diff --git a/README.md b/README.md
index 76f1008..cc2b9e9 100644
--- a/README.md
+++ b/README.md
@@ -9,11 +9,27 @@ make build
 ## Probe for the board
 Run
 ```sh
-st-info --probe 
+st-info --probe
 ```
 
 ## Flashing
 Run
 ```sh
-make flash 
+make flash
 ```
+
+## Debugging
+
+### `st-info --probe` shows 0KB flash
+```
+> sudo st-info --probe
+Found 1 stlink programmers
+  version:    V2J43S28
+  serial:     0671FF343056363043090732
+  flash:      0 (pagesize: 16384)      <--- 0KB flash
+  sram:       131072
+  chipid:     0x431
+  dev-type:   STM32F411xC_xE
+```
+This can happen when the flash is locked. One way to unlock it is to erase the entire chip via the
+Windows application `ST-Link Util`.
diff --git a/build/final.elf b/build/final.elf
index 8e6b73c..54f770f 100755
Binary files a/build/final.elf and b/build/final.elf differ
diff --git a/build/final.elf.map b/build/final.elf.map
index bfba6d0..6427ca2 100644
--- a/build/final.elf.map
+++ b/build/final.elf.map
@@ -53,7 +53,7 @@ Discarded input sections
  .debug_macro   0x00000000       0x89 build/main.o
  .debug_macro   0x00000000      0x4cc build/main.o
  .debug_macro   0x00000000       0x22 build/main.o
- .debug_macro   0x00000000       0x88 build/main.o
+ .debug_macro   0x00000000       0xa0 build/main.o
  .group         0x00000000        0xc build/startup.o
  .group         0x00000000        0xc build/startup.o
  .group         0x00000000        0xc build/startup.o
@@ -128,7 +128,7 @@ Discarded input sections
  .debug_macro   0x00000000      0x1df build/usart.o
  .debug_macro   0x00000000       0x89 build/usart.o
  .debug_macro   0x00000000      0x4cc build/usart.o
- .debug_macro   0x00000000      0x13e build/usart.o
+ .debug_macro   0x00000000      0x19f build/usart.o
  .debug_macro   0x00000000       0x22 build/usart.o
  .debug_macro   0x00000000       0x82 build/usart.o
 
@@ -157,7 +157,7 @@ LOAD build/usart.o
                 0x08000000                interrupt_vector_table
                 0x08000198                        . = ALIGN (0x4)
 
-.text           0x08000198      0x4e4
+.text           0x08000198      0x4d4
                 0x08000198                        . = ALIGN (0x4)
  *(.text)
  *(.text.*)
@@ -169,129 +169,129 @@ LOAD build/usart.o
                 0x080001fa                gpio_write
  *fill*         0x08000246        0x2 
  .text.system_clock_init
-                0x08000248      0x144 build/main.o
- .text.main     0x0800038c       0x9c build/main.o
-                0x0800038c                main
+                0x08000248      0x128 build/main.o
+ .text.main     0x08000370       0x9c build/main.o
+                0x08000370                main
  .text.init_memory
-                0x08000428       0x64 build/startup.o
-                0x08000428                init_memory
- .text.reset    0x0800048c       0x10 build/startup.o
-                0x0800048c                reset
+                0x0800040c       0x64 build/startup.o
+                0x0800040c                init_memory
+ .text.reset    0x08000470       0x10 build/startup.o
+                0x08000470                reset
  .text.default_handler
-                0x0800049c        0x8 build/startup.o
-                0x0800049c                exti0
-                0x0800049c                debug_monitor
-                0x0800049c                rcc
-                0x0800049c                x
-                0x0800049c                sdio
-                0x0800049c                usage_fault
-                0x0800049c                tim1_up_tim10
-                0x0800049c                usart1
-                0x0800049c                i2c3_er
-                0x0800049c                spi2
-                0x0800049c                dma1_stream1
-                0x0800049c                bus_fault
-                0x0800049c                spi5
-                0x0800049c                exti3
-                0x0800049c                dma2_stream5
-                0x0800049c                tim2
-                0x0800049c                dma1_stream6
-                0x0800049c                default_handler
-                0x0800049c                i2c1_er
-                0x0800049c                hard_fault
-                0x0800049c                usart6
-                0x0800049c                exti15_10
-                0x0800049c                usart2
-                0x0800049c                pend_sv
-                0x0800049c                i2c1_ev
-                0x0800049c                wwdg
-                0x0800049c                adc
-                0x0800049c                rtc_alarm
-                0x0800049c                spi3
-                0x0800049c                exti1
-                0x0800049c                mem_manage
-                0x0800049c                dma2_stream1
-                0x0800049c                dma1_stream2
-                0x0800049c                dma2_stream3
-                0x0800049c                sv_call
-                0x0800049c                tim3
-                0x0800049c                otg_fs
-                0x0800049c                dma1_stream5
-                0x0800049c                dma2_stream6
-                0x0800049c                flash
-                0x0800049c                tamp_stamp
-                0x0800049c                i2c3_ev
-                0x0800049c                rtc_wkup
-                0x0800049c                dma2_stream0
-                0x0800049c                pvd
-                0x0800049c                fpu
-                0x0800049c                exti4
-                0x0800049c                exti2
-                0x0800049c                spi1
-                0x0800049c                dma1_stream0
-                0x0800049c                tim1_brk_tim9
-                0x0800049c                i2c2_ev
-                0x0800049c                otg_fs_wkup
-                0x0800049c                spi4
-                0x0800049c                dma2_stream2
-                0x0800049c                tim1_cc
-                0x0800049c                tim1_trg_com_tim11
-                0x0800049c                exti9_5
-                0x0800049c                dma1_stream3
-                0x0800049c                dma2_stream4
-                0x0800049c                i2c2_er
-                0x0800049c                dma2_stream7
-                0x0800049c                dma1_stream7
-                0x0800049c                nmi
-                0x0800049c                systick
-                0x0800049c                tim4
-                0x0800049c                tim5
-                0x0800049c                dma1_stream4
+                0x08000480        0x8 build/startup.o
+                0x08000480                exti0
+                0x08000480                debug_monitor
+                0x08000480                rcc
+                0x08000480                x
+                0x08000480                sdio
+                0x08000480                usage_fault
+                0x08000480                tim1_up_tim10
+                0x08000480                usart1
+                0x08000480                i2c3_er
+                0x08000480                spi2
+                0x08000480                dma1_stream1
+                0x08000480                bus_fault
+                0x08000480                spi5
+                0x08000480                exti3
+                0x08000480                dma2_stream5
+                0x08000480                tim2
+                0x08000480                dma1_stream6
+                0x08000480                default_handler
+                0x08000480                i2c1_er
+                0x08000480                hard_fault
+                0x08000480                usart6
+                0x08000480                exti15_10
+                0x08000480                usart2
+                0x08000480                pend_sv
+                0x08000480                i2c1_ev
+                0x08000480                wwdg
+                0x08000480                adc
+                0x08000480                rtc_alarm
+                0x08000480                spi3
+                0x08000480                exti1
+                0x08000480                mem_manage
+                0x08000480                dma2_stream1
+                0x08000480                dma1_stream2
+                0x08000480                dma2_stream3
+                0x08000480                sv_call
+                0x08000480                tim3
+                0x08000480                otg_fs
+                0x08000480                dma1_stream5
+                0x08000480                dma2_stream6
+                0x08000480                flash
+                0x08000480                tamp_stamp
+                0x08000480                i2c3_ev
+                0x08000480                rtc_wkup
+                0x08000480                dma2_stream0
+                0x08000480                pvd
+                0x08000480                fpu
+                0x08000480                exti4
+                0x08000480                exti2
+                0x08000480                spi1
+                0x08000480                dma1_stream0
+                0x08000480                tim1_brk_tim9
+                0x08000480                i2c2_ev
+                0x08000480                otg_fs_wkup
+                0x08000480                spi4
+                0x08000480                dma2_stream2
+                0x08000480                tim1_cc
+                0x08000480                tim1_trg_com_tim11
+                0x08000480                exti9_5
+                0x08000480                dma1_stream3
+                0x08000480                dma2_stream4
+                0x08000480                i2c2_er
+                0x08000480                dma2_stream7
+                0x08000480                dma1_stream7
+                0x08000480                nmi
+                0x08000480                systick
+                0x08000480                tim4
+                0x08000480                tim5
+                0x08000480                dma1_stream4
  .text.tim4_init
-                0x080004a4       0x40 build/timer.o
-                0x080004a4                tim4_init
+                0x08000488       0x40 build/timer.o
+                0x08000488                tim4_init
  .text.tim4_start
-                0x080004e4       0x20 build/timer.o
-                0x080004e4                tim4_start
+                0x080004c8       0x20 build/timer.o
+                0x080004c8                tim4_start
  .text.usart2_init
-                0x08000504       0xec build/usart.o
-                0x08000504                usart2_init
+                0x080004e8       0xf8 build/usart.o
+                0x080004e8                usart2_init
  .text.usart2_start
-                0x080005f0       0x20 build/usart.o
-                0x080005f0                usart2_start
+                0x080005e0       0x20 build/usart.o
+                0x080005e0                usart2_start
  .text.usart2_write_byte
-                0x08000610       0x30 build/usart.o
-                0x08000610                usart2_write_byte
+                0x08000600       0x30 build/usart.o
+                0x08000600                usart2_write_byte
  .text.usart2_write
-                0x08000640       0x2a build/usart.o
-                0x08000640                usart2_write
+                0x08000630       0x2a build/usart.o
+                0x08000630                usart2_write
  *(.rodata)
- *fill*         0x0800066a        0x2 
- .rodata        0x0800066c        0xe build/main.o
+ *fill*         0x0800065a        0x2 
+ .rodata        0x0800065c        0xf build/main.o
  *(.rodata.*)
-                0x0800067c                        . = ALIGN (0x4)
- *fill*         0x0800067a        0x2 
-                0x0800067c                        _data_addr = LOADADDR (.data)
+                0x0800066c                        . = ALIGN (0x4)
+ *fill*         0x0800066b        0x1 
+                0x0800066c                        _data_addr = LOADADDR (.data)
 
-.glue_7         0x0800067c        0x0
- .glue_7        0x0800067c        0x0 linker stubs
+.glue_7         0x0800066c        0x0
+ .glue_7        0x0800066c        0x0 linker stubs
 
-.glue_7t        0x0800067c        0x0
- .glue_7t       0x0800067c        0x0 linker stubs
+.glue_7t        0x0800066c        0x0
+ .glue_7t       0x0800066c        0x0 linker stubs
 
-.vfp11_veneer   0x0800067c        0x0
- .vfp11_veneer  0x0800067c        0x0 linker stubs
+.vfp11_veneer   0x0800066c        0x0
+ .vfp11_veneer  0x0800066c        0x0 linker stubs
 
-.v4_bx          0x0800067c        0x0
- .v4_bx         0x0800067c        0x0 linker stubs
+.v4_bx          0x0800066c        0x0
+ .v4_bx         0x0800066c        0x0 linker stubs
 
-.iplt           0x0800067c        0x0
- .iplt          0x0800067c        0x0 build/main.o
+.iplt           0x0800066c        0x0
+ .iplt          0x0800066c        0x0 build/main.o
 
-.rel.dyn        0x0800067c        0x0
- .rel.iplt      0x0800067c        0x0 build/main.o
+.rel.dyn        0x0800066c        0x0
+ .rel.iplt      0x0800066c        0x0 build/main.o
 
-.data           0x20000000        0x0 load address 0x0800067c
+.data           0x20000000        0x0 load address 0x0800066c
                 0x20000000                        . = ALIGN (0x4)
                 0x20000000                        _data_start = .
  *(.data)
@@ -299,10 +299,10 @@ LOAD build/usart.o
                 0x20000000                        . = ALIGN (0x4)
                 0x20000000                        _data_end = .
 
-.igot.plt       0x20000000        0x0 load address 0x0800067c
+.igot.plt       0x20000000        0x0 load address 0x0800066c
  .igot.plt      0x20000000        0x0 build/main.o
 
-.bss            0x20000000        0x0 load address 0x0800067c
+.bss            0x20000000        0x0 load address 0x0800066c
                 0x20000000                        . = ALIGN (0x4)
                 0x20000000                        _bss_start = .
  *(.bss)
@@ -351,7 +351,7 @@ LOAD linker stubs
  .debug_rnglists
                 0x0000006c       0x26 build/usart.o
 
-.debug_macro    0x00000000     0x48a9
+.debug_macro    0x00000000     0x499b
  .debug_macro   0x00000000      0xb56 build/gpio.o
  .debug_macro   0x00000b56       0x22 build/gpio.o
  .debug_macro   0x00000b78       0x75 build/gpio.o
@@ -366,39 +366,39 @@ LOAD linker stubs
  .debug_macro   0x0000108c       0x89 build/gpio.o
  .debug_macro   0x00001115      0x4cc build/gpio.o
  .debug_macro   0x000015e1       0x22 build/gpio.o
- .debug_macro   0x00001603       0x88 build/gpio.o
- .debug_macro   0x0000168b      0xb89 build/main.o
- .debug_macro   0x00002214      0x144 build/main.o
- .debug_macro   0x00002358       0x46 build/main.o
- .debug_macro   0x0000239e       0x2e build/main.o
- .debug_macro   0x000023cc       0x22 build/main.o
- .debug_macro   0x000023ee       0x82 build/main.o
- .debug_macro   0x00002470      0xb02 build/startup.o
- .debug_macro   0x00002f72       0x56 build/startup.o
- .debug_macro   0x00002fc8       0x51 build/startup.o
- .debug_macro   0x00003019      0xb5c build/timer.o
- .debug_macro   0x00003b75      0x13e build/timer.o
- .debug_macro   0x00003cb3      0xb74 build/usart.o
- .debug_macro   0x00004827       0x82 build/usart.o
+ .debug_macro   0x00001603       0xa0 build/gpio.o
+ .debug_macro   0x000016a3      0xb89 build/main.o
+ .debug_macro   0x0000222c      0x1a5 build/main.o
+ .debug_macro   0x000023d1       0x46 build/main.o
+ .debug_macro   0x00002417       0x2e build/main.o
+ .debug_macro   0x00002445       0x22 build/main.o
+ .debug_macro   0x00002467       0x82 build/main.o
+ .debug_macro   0x000024e9      0xb02 build/startup.o
+ .debug_macro   0x00002feb       0x56 build/startup.o
+ .debug_macro   0x00003041       0x51 build/startup.o
+ .debug_macro   0x00003092      0xb5c build/timer.o
+ .debug_macro   0x00003bee      0x19f build/timer.o
+ .debug_macro   0x00003d8d      0xb74 build/usart.o
+ .debug_macro   0x00004901       0x9a build/usart.o
 
-.debug_line     0x00000000      0x661
+.debug_line     0x00000000      0x65d
  .debug_line    0x00000000      0x116 build/gpio.o
- .debug_line    0x00000116      0x1e4 build/main.o
- .debug_line    0x000002fa       0xea build/startup.o
- .debug_line    0x000003e4       0xdf build/timer.o
- .debug_line    0x000004c3      0x19e build/usart.o
+ .debug_line    0x00000116      0x1da build/main.o
+ .debug_line    0x000002f0       0xea build/startup.o
+ .debug_line    0x000003da       0xdf build/timer.o
+ .debug_line    0x000004b9      0x1a4 build/usart.o
 
-.debug_str      0x00000000     0x63e6
- .debug_str     0x00000000     0x5508 build/gpio.o
-                               0x56b0 (size before relaxing)
- .debug_str     0x00005508      0xe17 build/main.o
-                               0x6477 (size before relaxing)
- .debug_str     0x0000631f       0x88 build/startup.o
+.debug_str      0x00000000     0x65c7
+ .debug_str     0x00000000     0x5574 build/gpio.o
+                               0x571c (size before relaxing)
+ .debug_str     0x00005574      0xf8c build/main.o
+                               0x6658 (size before relaxing)
+ .debug_str     0x00006500       0x88 build/startup.o
                                0x3cdc (size before relaxing)
- .debug_str     0x000063a7        0xc build/timer.o
-                               0x5bc2 (size before relaxing)
- .debug_str     0x000063b3       0x33 build/usart.o
-                               0x60ec (size before relaxing)
+ .debug_str     0x00006588        0xc build/timer.o
+                               0x5d37 (size before relaxing)
+ .debug_str     0x00006594       0x33 build/usart.o
+                               0x62cd (size before relaxing)
 
 .comment        0x00000000       0x45
  .comment       0x00000000       0x45 build/gpio.o
diff --git a/build/gpio.S b/build/gpio.S
index a59bc5e..de0bc90 100644
--- a/build/gpio.S
+++ b/build/gpio.S
@@ -188,10 +188,10 @@ gpio_write:
 	.byte	0x4
 	.4byte	.Ldebug_abbrev0
 	.uleb128 0x8
-	.4byte	.LASF908
+	.4byte	.LASF912
 	.byte	0x1d
-	.4byte	.LASF909
-	.4byte	.LASF910
+	.4byte	.LASF913
+	.4byte	.LASF914
 	.4byte	.LLRL0
 	.4byte	0
 	.4byte	.Ldebug_line0
@@ -199,17 +199,17 @@ gpio_write:
 	.uleb128 0x1
 	.byte	0x1
 	.byte	0x6
-	.4byte	.LASF877
+	.4byte	.LASF881
 	.uleb128 0x1
 	.byte	0x1
 	.byte	0x8
-	.4byte	.LASF878
+	.4byte	.LASF882
 	.uleb128 0x1
 	.byte	0x2
 	.byte	0x5
-	.4byte	.LASF879
+	.4byte	.LASF883
 	.uleb128 0x3
-	.4byte	.LASF882
+	.4byte	.LASF886
 	.byte	0x2
 	.byte	0x39
 	.byte	0x1c
@@ -217,13 +217,13 @@ gpio_write:
 	.uleb128 0x1
 	.byte	0x2
 	.byte	0x7
-	.4byte	.LASF880
+	.4byte	.LASF884
 	.uleb128 0x1
 	.byte	0x4
 	.byte	0x5
-	.4byte	.LASF881
+	.4byte	.LASF885
 	.uleb128 0x3
-	.4byte	.LASF883
+	.4byte	.LASF887
 	.byte	0x2
 	.byte	0x4f
 	.byte	0x1b
@@ -231,21 +231,21 @@ gpio_write:
 	.uleb128 0x1
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF884
+	.4byte	.LASF888
 	.uleb128 0x1
 	.byte	0x8
 	.byte	0x5
-	.4byte	.LASF885
+	.4byte	.LASF889
 	.uleb128 0x1
 	.byte	0x8
 	.byte	0x7
-	.4byte	.LASF886
+	.4byte	.LASF890
 	.uleb128 0x9
 	.byte	0x4
 	.byte	0x5
 	.ascii	"int\000"
 	.uleb128 0x3
-	.4byte	.LASF887
+	.4byte	.LASF891
 	.byte	0x2
 	.byte	0xe8
 	.byte	0x16
@@ -253,15 +253,15 @@ gpio_write:
 	.uleb128 0x1
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF888
+	.4byte	.LASF892
 	.uleb128 0x3
-	.4byte	.LASF889
+	.4byte	.LASF893
 	.byte	0x3
 	.byte	0x24
 	.byte	0x14
 	.4byte	0x3f
 	.uleb128 0x3
-	.4byte	.LASF890
+	.4byte	.LASF894
 	.byte	0x3
 	.byte	0x30
 	.byte	0x14
@@ -269,35 +269,35 @@ gpio_write:
 	.uleb128 0xa
 	.4byte	0xa0
 	.uleb128 0x3
-	.4byte	.LASF891
+	.4byte	.LASF895
 	.byte	0x3
 	.byte	0x52
 	.byte	0x15
 	.4byte	0x81
 	.uleb128 0xb
-	.4byte	.LASF907
+	.4byte	.LASF911
 	.byte	0x28
 	.byte	0x4
 	.byte	0x7
 	.byte	0x8
 	.4byte	0x139
 	.uleb128 0x2
-	.4byte	.LASF892
+	.4byte	.LASF896
 	.byte	0x8
 	.4byte	0xac
 	.byte	0
 	.uleb128 0x2
-	.4byte	.LASF893
+	.4byte	.LASF897
 	.byte	0x9
 	.4byte	0xac
 	.byte	0x4
 	.uleb128 0x2
-	.4byte	.LASF894
+	.4byte	.LASF898
 	.byte	0xa
 	.4byte	0xac
 	.byte	0x8
 	.uleb128 0x2
-	.4byte	.LASF895
+	.4byte	.LASF899
 	.byte	0xb
 	.4byte	0xac
 	.byte	0xc
@@ -312,22 +312,22 @@ gpio_write:
 	.4byte	0xac
 	.byte	0x14
 	.uleb128 0x2
-	.4byte	.LASF896
+	.4byte	.LASF900
 	.byte	0xe
 	.4byte	0xac
 	.byte	0x18
 	.uleb128 0x2
-	.4byte	.LASF897
+	.4byte	.LASF901
 	.byte	0xf
 	.4byte	0xac
 	.byte	0x1c
 	.uleb128 0x2
-	.4byte	.LASF898
+	.4byte	.LASF902
 	.byte	0x10
 	.4byte	0xac
 	.byte	0x20
 	.uleb128 0x2
-	.4byte	.LASF899
+	.4byte	.LASF903
 	.byte	0x11
 	.4byte	0xac
 	.byte	0x24
@@ -337,30 +337,30 @@ gpio_write:
 	.byte	0x1
 	.4byte	0x31
 	.byte	0x4
-	.byte	0x38
+	.byte	0x40
 	.byte	0xe
 	.4byte	0x160
 	.uleb128 0x4
-	.4byte	.LASF900
+	.4byte	.LASF904
 	.byte	0
 	.uleb128 0x4
-	.4byte	.LASF901
+	.4byte	.LASF905
 	.byte	0x1
 	.uleb128 0x4
-	.4byte	.LASF902
+	.4byte	.LASF906
 	.byte	0x2
 	.uleb128 0x4
-	.4byte	.LASF903
+	.4byte	.LASF907
 	.byte	0x3
 	.byte	0
 	.uleb128 0x3
-	.4byte	.LASF904
+	.4byte	.LASF908
 	.byte	0x4
-	.byte	0x3d
+	.byte	0x45
 	.byte	0x3
 	.4byte	0x139
 	.uleb128 0xd
-	.4byte	.LASF911
+	.4byte	.LASF915
 	.byte	0x1
 	.byte	0xd
 	.byte	0x6
@@ -386,7 +386,7 @@ gpio_write:
 	.byte	0x91
 	.sleb128 -19
 	.uleb128 0x7
-	.4byte	.LASF907
+	.4byte	.LASF911
 	.byte	0xe
 	.4byte	0x1b3
 	.uleb128 0x2
@@ -396,12 +396,12 @@ gpio_write:
 	.uleb128 0x1
 	.byte	0x1
 	.byte	0x2
-	.4byte	.LASF905
+	.4byte	.LASF909
 	.uleb128 0xe
 	.byte	0x4
 	.4byte	0xbd
 	.uleb128 0xf
-	.4byte	.LASF912
+	.4byte	.LASF916
 	.byte	0x1
 	.byte	0x6
 	.byte	0x6
@@ -418,7 +418,7 @@ gpio_write:
 	.byte	0x91
 	.sleb128 -18
 	.uleb128 0x10
-	.4byte	.LASF906
+	.4byte	.LASF910
 	.byte	0x1
 	.byte	0x6
 	.byte	0x2c
@@ -427,7 +427,7 @@ gpio_write:
 	.byte	0x91
 	.sleb128 -19
 	.uleb128 0x7
-	.4byte	.LASF907
+	.4byte	.LASF911
 	.byte	0x7
 	.4byte	0x1b3
 	.uleb128 0x2
@@ -3525,7 +3525,7 @@ gpio_write:
 	.uleb128 0x32
 	.4byte	.LASF854
 	.byte	0
-	.section	.debug_macro,"G",%progbits,wm4.gpio.h.2.482807a1c0512cd436d5862f3edb1adc,comdat
+	.section	.debug_macro,"G",%progbits,wm4.gpio.h.2.bc74b8bd59193b3190f972f5d232b4bf,comdat
 .Ldebug_macro15:
 	.2byte	0x5
 	.byte	0
@@ -3542,40 +3542,40 @@ gpio_write:
 	.uleb128 0x18
 	.4byte	.LASF858
 	.byte	0x5
-	.uleb128 0x19
+	.uleb128 0x1a
 	.4byte	.LASF859
 	.byte	0x5
-	.uleb128 0x1a
+	.uleb128 0x1b
 	.4byte	.LASF860
 	.byte	0x5
-	.uleb128 0x1c
+	.uleb128 0x1d
 	.4byte	.LASF861
 	.byte	0x5
-	.uleb128 0x1d
+	.uleb128 0x1e
 	.4byte	.LASF862
 	.byte	0x5
-	.uleb128 0x1e
+	.uleb128 0x20
 	.4byte	.LASF863
 	.byte	0x5
 	.uleb128 0x21
 	.4byte	.LASF864
 	.byte	0x5
-	.uleb128 0x22
+	.uleb128 0x24
 	.4byte	.LASF865
 	.byte	0x5
-	.uleb128 0x23
+	.uleb128 0x25
 	.4byte	.LASF866
 	.byte	0x5
-	.uleb128 0x25
+	.uleb128 0x26
 	.4byte	.LASF867
 	.byte	0x5
-	.uleb128 0x26
+	.uleb128 0x29
 	.4byte	.LASF868
 	.byte	0x5
-	.uleb128 0x27
+	.uleb128 0x2a
 	.4byte	.LASF869
 	.byte	0x5
-	.uleb128 0x2c
+	.uleb128 0x2b
 	.4byte	.LASF870
 	.byte	0x5
 	.uleb128 0x2d
@@ -3584,17 +3584,29 @@ gpio_write:
 	.uleb128 0x2e
 	.4byte	.LASF872
 	.byte	0x5
-	.uleb128 0x30
+	.uleb128 0x2f
 	.4byte	.LASF873
 	.byte	0x5
-	.uleb128 0x32
+	.uleb128 0x34
 	.4byte	.LASF874
 	.byte	0x5
-	.uleb128 0x34
+	.uleb128 0x35
 	.4byte	.LASF875
 	.byte	0x5
 	.uleb128 0x36
 	.4byte	.LASF876
+	.byte	0x5
+	.uleb128 0x38
+	.4byte	.LASF877
+	.byte	0x5
+	.uleb128 0x3a
+	.4byte	.LASF878
+	.byte	0x5
+	.uleb128 0x3c
+	.4byte	.LASF879
+	.byte	0x5
+	.uleb128 0x3e
+	.4byte	.LASF880
 	.byte	0
 	.section	.debug_line,"",%progbits
 .Ldebug_line0:
@@ -3639,7 +3651,7 @@ gpio_write:
 	.ascii	"__PTRDIFF_MAX__ 0x7fffffff\000"
 .LASF541:
 	.ascii	"_LONG_DOUBLE long double\000"
-.LASF907:
+.LASF911:
 	.ascii	"gpio\000"
 .LASF591:
 	.ascii	"INT_LEAST8_MIN (-__INT_LEAST8_MAX__ - 1)\000"
@@ -3647,7 +3659,7 @@ gpio_write:
 	.ascii	"_UINT32_T_DECLARED \000"
 .LASF90:
 	.ascii	"__INTMAX_MAX__ 0x7fffffffffffffffLL\000"
-.LASF902:
+.LASF906:
 	.ascii	"GPIO_MODE_AF\000"
 .LASF335:
 	.ascii	"__TQ_IBIT__ 0\000"
@@ -3711,8 +3723,6 @@ gpio_write:
 	.ascii	"PRIXFAST32 __PRI32FAST(X)\000"
 .LASF525:
 	.ascii	"__INT8 \"hh\"\000"
-.LASF860:
-	.ascii	"GPIO_MODER_MODER3_AF (0b10)\000"
 .LASF47:
 	.ascii	"__UINT8_TYPE__ unsigned char\000"
 .LASF368:
@@ -3765,12 +3775,14 @@ gpio_write:
 	.ascii	"__need_wchar_t\000"
 .LASF199:
 	.ascii	"__FLT32_MIN_EXP__ (-125)\000"
-.LASF908:
+.LASF912:
 	.ascii	"GNU C2X 12.3.1 20230626 -mcpu=cortex-m4 -mthumb -mf"
 	.ascii	"loat-abi=hard -mfpu=fpv4-sp-d16 -march=armv7e-m+fp "
 	.ascii	"-g3 -ggdb -O0 -std=c2x -ffunction-sections -fdata-s"
 	.ascii	"ections -fno-builtin -fno-common\000"
-.LASF864:
+.LASF865:
+	.ascii	"GPIO_AFRH_AFRH8_BIT 0\000"
+.LASF868:
 	.ascii	"GPIO_AFRL_AFRL3_BIT 12\000"
 .LASF595:
 	.ascii	"INT16_MAX (__INT16_MAX__)\000"
@@ -3852,7 +3864,7 @@ gpio_write:
 	.ascii	"__INT64 \"ll\"\000"
 .LASF138:
 	.ascii	"__INTPTR_MAX__ 0x7fffffff\000"
-.LASF872:
+.LASF876:
 	.ascii	"GPIO(port) ((struct gpio*)(uintptr_t)(GPIO_BASE_ADD"
 	.ascii	"R + (GPIO_PORT_OFFSET * port)))\000"
 .LASF499:
@@ -3888,7 +3900,7 @@ gpio_write:
 	.ascii	"PRId64 __PRI64(d)\000"
 .LASF302:
 	.ascii	"__UACCUM_IBIT__ 16\000"
-.LASF881:
+.LASF885:
 	.ascii	"long int\000"
 .LASF818:
 	.ascii	"PRIXFAST64 __PRI64FAST(X)\000"
@@ -3916,6 +3928,8 @@ gpio_write:
 	.ascii	"PRIdFAST32 __PRI32FAST(d)\000"
 .LASF93:
 	.ascii	"__UINTMAX_C(c) c ## ULL\000"
+.LASF866:
+	.ascii	"GPIO_AFRH_AFRH8_MASK (0b1111)\000"
 .LASF31:
 	.ascii	"__SIZEOF_POINTER__ 4\000"
 .LASF621:
@@ -3924,8 +3938,6 @@ gpio_write:
 	.ascii	"__GCC_ATOMIC_BOOL_LOCK_FREE 2\000"
 .LASF554:
 	.ascii	"___int64_t_defined 1\000"
-.LASF863:
-	.ascii	"GPIO_MODER_MODER2_AF (0b10)\000"
 .LASF432:
 	.ascii	"__ARM_NEON__\000"
 .LASF587:
@@ -3986,7 +3998,7 @@ gpio_write:
 	.ascii	"PRIoLEAST16 __PRI16LEAST(o)\000"
 .LASF458:
 	.ascii	"__NEWLIB__ 4\000"
-.LASF900:
+.LASF904:
 	.ascii	"GPIO_MODE_INPUT\000"
 .LASF720:
 	.ascii	"SCNi16 __SCN16(i)\000"
@@ -3996,7 +4008,7 @@ gpio_write:
 	.ascii	"__FLT_DECIMAL_DIG__ 9\000"
 .LASF562:
 	.ascii	"_UINT8_T_DECLARED \000"
-.LASF877:
+.LASF881:
 	.ascii	"signed char\000"
 .LASF805:
 	.ascii	"PRIuLEAST64 __PRI64LEAST(u)\000"
@@ -4008,7 +4020,7 @@ gpio_write:
 	.ascii	"__ARM_FEATURE_FMA 1\000"
 .LASF364:
 	.ascii	"__GNUC_STDC_INLINE__ 1\000"
-.LASF904:
+.LASF908:
 	.ascii	"GPIO_MODE\000"
 .LASF256:
 	.ascii	"__FRACT_FBIT__ 15\000"
@@ -4030,11 +4042,11 @@ gpio_write:
 	.ascii	"__SACCUM_MAX__ 0X7FFFP-7HK\000"
 .LASF219:
 	.ascii	"__FLT64_MAX_10_EXP__ 308\000"
-.LASF868:
+.LASF872:
 	.ascii	"GPIO_AFRL_AFRL2_MASK (0b1111)\000"
 .LASF65:
 	.ascii	"__UINT_FAST32_TYPE__ unsigned int\000"
-.LASF878:
+.LASF882:
 	.ascii	"unsigned char\000"
 .LASF3:
 	.ascii	"__STDC_UTF_32__ 1\000"
@@ -4082,13 +4094,13 @@ gpio_write:
 	.ascii	"__int_fast64_t_defined 1\000"
 .LASF837:
 	.ascii	"__PRIPTR(x) __STRINGIFY(x)\000"
-.LASF889:
+.LASF893:
 	.ascii	"uint16_t\000"
 .LASF417:
 	.ascii	"__thumb2__ 1\000"
 .LASF321:
 	.ascii	"__ULLACCUM_FBIT__ 32\000"
-.LASF905:
+.LASF909:
 	.ascii	"_Bool\000"
 .LASF366:
 	.ascii	"__STRICT_ANSI__ 1\000"
@@ -4106,7 +4118,7 @@ gpio_write:
 	.ascii	"__PRAGMA_REDEFINE_EXTNAME 1\000"
 .LASF36:
 	.ascii	"__WCHAR_TYPE__ unsigned int\000"
-.LASF901:
+.LASF905:
 	.ascii	"GPIO_MODE_OUTPUT\000"
 .LASF357:
 	.ascii	"__USA_IBIT__ 16\000"
@@ -4144,7 +4156,7 @@ gpio_write:
 	.ascii	"__SCN64(x) __INT64 __STRINGIFY(x)\000"
 .LASF646:
 	.ascii	"_GCC_WRAP_STDINT_H \000"
-.LASF882:
+.LASF886:
 	.ascii	"__uint16_t\000"
 .LASF224:
 	.ascii	"__FLT64_EPSILON__ 2.2204460492503131e-16F64\000"
@@ -4172,7 +4184,7 @@ gpio_write:
 	.ascii	"INTMAX_MAX (__INTMAX_MAX__)\000"
 .LASF601:
 	.ascii	"INT32_MAX (__INT32_MAX__)\000"
-.LASF873:
+.LASF877:
 	.ascii	"BIT(x) (1 << x)\000"
 .LASF469:
 	.ascii	"_MB_LEN_MAX 8\000"
@@ -4190,7 +4202,7 @@ gpio_write:
 	.ascii	"_END_STD_C \000"
 .LASF852:
 	.ascii	"true ((_Bool)+1u)\000"
-.LASF865:
+.LASF869:
 	.ascii	"GPIO_AFRL_AFRL3_MASK (0b1111)\000"
 .LASF599:
 	.ascii	"UINT_LEAST16_MAX (__UINT_LEAST16_MAX__)\000"
@@ -4204,7 +4216,7 @@ gpio_write:
 	.ascii	"__FLT_EPSILON__ 1.1920928955078125e-7F\000"
 .LASF376:
 	.ascii	"__GCC_ATOMIC_SHORT_LOCK_FREE 2\000"
-.LASF874:
+.LASF878:
 	.ascii	"PIN(port,num) ((((port) - 'A') << 8) | num)\000"
 .LASF806:
 	.ascii	"PRIxLEAST64 __PRI64LEAST(x)\000"
@@ -4270,7 +4282,7 @@ gpio_write:
 	.ascii	"__FP_FAST_FMAF 1\000"
 .LASF628:
 	.ascii	"SIG_ATOMIC_MIN (-__STDINT_EXP(INT_MAX) - 1)\000"
-.LASF869:
+.LASF873:
 	.ascii	"GPIO_AFRL_AFRL2_USART2_TX (0b0111)\000"
 .LASF564:
 	.ascii	"_INT16_T_DECLARED \000"
@@ -4294,6 +4306,8 @@ gpio_write:
 	.ascii	"__ARM_FEATURE_FP16_FML\000"
 .LASF802:
 	.ascii	"PRIdLEAST64 __PRI64LEAST(d)\000"
+.LASF858:
+	.ascii	"GPIO_MODER_AF_MODE (0b10)\000"
 .LASF255:
 	.ascii	"__USFRACT_EPSILON__ 0x1P-8UHR\000"
 .LASF762:
@@ -4314,7 +4328,7 @@ gpio_write:
 	.ascii	"INT64_C(x) __INT64_C(x)\000"
 .LASF615:
 	.ascii	"INT_FAST16_MIN (-__INT_FAST16_MAX__ - 1)\000"
-.LASF862:
+.LASF864:
 	.ascii	"GPIO_MODER_MODER2_MASK (0b11)\000"
 .LASF106:
 	.ascii	"__INT_LEAST8_MAX__ 0x7f\000"
@@ -4342,6 +4356,8 @@ gpio_write:
 	.ascii	"__PRI8LEAST(x) __LEAST8 __STRINGIFY(x)\000"
 .LASF174:
 	.ascii	"__DBL_EPSILON__ ((double)2.2204460492503131e-16L)\000"
+.LASF860:
+	.ascii	"GPIO_MODER_MODER8_MASK (0b11)\000"
 .LASF268:
 	.ascii	"__LFRACT_MIN__ (-0.5LR-0.5LR)\000"
 .LASF117:
@@ -4364,7 +4380,7 @@ gpio_write:
 	.ascii	"___int8_t_defined 1\000"
 .LASF248:
 	.ascii	"__SFRACT_MIN__ (-0.5HR-0.5HR)\000"
-.LASF884:
+.LASF888:
 	.ascii	"long unsigned int\000"
 .LASF349:
 	.ascii	"__SA_IBIT__ 16\000"
@@ -4380,7 +4396,7 @@ gpio_write:
 	.ascii	"__ARM_FP16_FORMAT_IEEE\000"
 .LASF48:
 	.ascii	"__UINT16_TYPE__ short unsigned int\000"
-.LASF911:
+.LASF915:
 	.ascii	"gpio_write\000"
 .LASF569:
 	.ascii	"__int32_t_defined 1\000"
@@ -4424,7 +4440,7 @@ gpio_write:
 	.ascii	"SCNx8 __SCN8(x)\000"
 .LASF208:
 	.ascii	"__FLT32_DENORM_MIN__ 1.4012984643248171e-45F32\000"
-.LASF912:
+.LASF916:
 	.ascii	"gpio_set_mode\000"
 .LASF125:
 	.ascii	"__UINT64_C(c) c ## ULL\000"
@@ -4446,7 +4462,7 @@ gpio_write:
 	.ascii	"__GCC_ATOMIC_CHAR16_T_LOCK_FREE 2\000"
 .LASF789:
 	.ascii	"__PRI64FAST(x) __FAST64 __STRINGIFY(x)\000"
-.LASF891:
+.LASF895:
 	.ascii	"uintptr_t\000"
 .LASF168:
 	.ascii	"__DBL_MAX_EXP__ 1024\000"
@@ -4494,7 +4510,7 @@ gpio_write:
 	.ascii	"PRIX32 __PRI32(X)\000"
 .LASF773:
 	.ascii	"SCNxLEAST32 __SCN32LEAST(x)\000"
-.LASF894:
+.LASF898:
 	.ascii	"OSPEEDR\000"
 .LASF711:
 	.ascii	"__SCN16LEAST(x) __LEAST16 __STRINGIFY(x)\000"
@@ -4524,7 +4540,7 @@ gpio_write:
 	.ascii	"__ULACCUM_MIN__ 0.0ULK\000"
 .LASF461:
 	.ascii	"_ATEXIT_DYNAMIC_ALLOC 1\000"
-.LASF883:
+.LASF887:
 	.ascii	"__uint32_t\000"
 .LASF188:
 	.ascii	"__LDBL_MAX__ 1.7976931348623157e+308L\000"
@@ -4534,7 +4550,7 @@ gpio_write:
 	.ascii	"__FLT_RADIX__ 2\000"
 .LASF454:
 	.ascii	"_INTTYPES_H \000"
-.LASF885:
+.LASF889:
 	.ascii	"long long int\000"
 .LASF401:
 	.ascii	"__ARM_FEATURE_CMSE\000"
@@ -4570,7 +4586,7 @@ gpio_write:
 	.ascii	"__WCHAR_T \000"
 .LASF223:
 	.ascii	"__FLT64_MIN__ 2.2250738585072014e-308F64\000"
-.LASF866:
+.LASF870:
 	.ascii	"GPIO_AFRL_AFRL3_USART2_RX (0b0111)\000"
 .LASF553:
 	.ascii	"___int32_t_defined 1\000"
@@ -4641,20 +4657,22 @@ gpio_write:
 	.ascii	"\000"
 .LASF582:
 	.ascii	"__int_fast16_t_defined 1\000"
-.LASF892:
+.LASF896:
 	.ascii	"MODER\000"
 .LASF482:
 	.ascii	"__FLOAT_TYPE float\000"
 .LASF185:
 	.ascii	"__LDBL_MAX_10_EXP__ 308\000"
+.LASF867:
+	.ascii	"GPIO_AFRH_AFRH8_MCO_1 (0b0000)\000"
 .LASF175:
 	.ascii	"__DBL_DENORM_MIN__ ((double)4.9406564584124654e-324"
 	.ascii	"L)\000"
 .LASF607:
 	.ascii	"INT64_MAX (__INT64_MAX__)\000"
-.LASF888:
+.LASF892:
 	.ascii	"unsigned int\000"
-.LASF887:
+.LASF891:
 	.ascii	"__uintptr_t\000"
 .LASF459:
 	.ascii	"__NEWLIB_MINOR__ 3\000"
@@ -4686,7 +4704,7 @@ gpio_write:
 	.ascii	"__CHAR_BIT__ 8\000"
 .LASF143:
 	.ascii	"__FLT_EVAL_METHOD__ 0\000"
-.LASF879:
+.LASF883:
 	.ascii	"short int\000"
 .LASF685:
 	.ascii	"PRIdLEAST8 __PRI8LEAST(d)\000"
@@ -4746,6 +4764,8 @@ gpio_write:
 	.ascii	"__ATFILE_VISIBLE 0\000"
 .LASF372:
 	.ascii	"__GCC_ATOMIC_CHAR_LOCK_FREE 2\000"
+.LASF859:
+	.ascii	"GPIO_MODER_MODER8_BIT 16\000"
 .LASF270:
 	.ascii	"__LFRACT_EPSILON__ 0x1P-31LR\000"
 .LASF808:
@@ -4812,7 +4832,7 @@ gpio_write:
 	.ascii	"__UFRACT_IBIT__ 0\000"
 .LASF399:
 	.ascii	"__ARM_32BIT_STATE 1\000"
-.LASF861:
+.LASF863:
 	.ascii	"GPIO_MODER_MODER2_BIT 4\000"
 .LASF107:
 	.ascii	"__INT8_C(c) c\000"
@@ -4826,13 +4846,13 @@ gpio_write:
 	.ascii	"SCNuFAST16 __SCN16FAST(u)\000"
 .LASF801:
 	.ascii	"SCNx64 __SCN64(x)\000"
-.LASF876:
+.LASF880:
 	.ascii	"PINPORT(pin) (pin >> 8)\000"
 .LASF198:
 	.ascii	"__FLT32_DIG__ 6\000"
 .LASF645:
 	.ascii	"UINTMAX_C(x) __UINTMAX_C(x)\000"
-.LASF859:
+.LASF862:
 	.ascii	"GPIO_MODER_MODER3_MASK (0b11)\000"
 .LASF623:
 	.ascii	"UINT_FAST64_MAX (__UINT_FAST64_MAX__)\000"
@@ -4876,7 +4896,7 @@ gpio_write:
 	.ascii	"__ORDER_LITTLE_ENDIAN__ 1234\000"
 .LASF155:
 	.ascii	"__FLT_NORM_MAX__ 3.4028234663852886e+38F\000"
-.LASF886:
+.LASF890:
 	.ascii	"long long unsigned int\000"
 .LASF611:
 	.ascii	"UINT_LEAST64_MAX (__UINT_LEAST64_MAX__)\000"
@@ -4906,8 +4926,8 @@ gpio_write:
 	.ascii	"SCNdFAST32 __SCN32FAST(d)\000"
 .LASF339:
 	.ascii	"__UHQ_IBIT__ 0\000"
-.LASF858:
-	.ascii	"GPIO_MODER_MODER3_BIT 7\000"
+.LASF861:
+	.ascii	"GPIO_MODER_MODER3_BIT 6\000"
 .LASF60:
 	.ascii	"__INT_FAST16_TYPE__ int\000"
 .LASF631:
@@ -4956,11 +4976,11 @@ gpio_write:
 	.ascii	"SCNdFAST8 __SCN8FAST(d)\000"
 .LASF576:
 	.ascii	"_UINTPTR_T_DECLARED \000"
-.LASF899:
+.LASF903:
 	.ascii	"AFRH\000"
 .LASF314:
 	.ascii	"__ULACCUM_MAX__ 0XFFFFFFFFFFFFFFFFP-32ULK\000"
-.LASF898:
+.LASF902:
 	.ascii	"AFRL\000"
 .LASF273:
 	.ascii	"__ULFRACT_MIN__ 0.0ULR\000"
@@ -4974,7 +4994,7 @@ gpio_write:
 	.ascii	"__INT32_TYPE__ long int\000"
 .LASF118:
 	.ascii	"__UINT_LEAST8_MAX__ 0xff\000"
-.LASF897:
+.LASF901:
 	.ascii	"LCKR\000"
 .LASF520:
 	.ascii	"__int20__ +2\000"
@@ -5020,7 +5040,7 @@ gpio_write:
 	.ascii	"__QQ_IBIT__ 0\000"
 .LASF763:
 	.ascii	"PRIdLEAST32 __PRI32LEAST(d)\000"
-.LASF893:
+.LASF897:
 	.ascii	"OTYPER\000"
 .LASF811:
 	.ascii	"SCNuLEAST64 __SCN64LEAST(u)\000"
@@ -5040,11 +5060,11 @@ gpio_write:
 	.ascii	"__GNUC_MINOR__ 3\000"
 .LASF57:
 	.ascii	"__UINT_LEAST32_TYPE__ long unsigned int\000"
-.LASF909:
+.LASF913:
 	.ascii	"src/gpio.c\000"
 .LASF405:
 	.ascii	"__ARM_FEATURE_NUMERIC_MAXMIN\000"
-.LASF870:
+.LASF874:
 	.ascii	"GPIO_BASE_ADDR (0x40020000U)\000"
 .LASF38:
 	.ascii	"__INTMAX_TYPE__ long long int\000"
@@ -5096,7 +5116,7 @@ gpio_write:
 	.ascii	"__SCN8(x) __INT8 __STRINGIFY(x)\000"
 .LASF23:
 	.ascii	"__SIZEOF_SIZE_T__ 4\000"
-.LASF871:
+.LASF875:
 	.ascii	"GPIO_PORT_OFFSET (0x400U)\000"
 .LASF50:
 	.ascii	"__UINT64_TYPE__ long long unsigned int\000"
@@ -5106,7 +5126,7 @@ gpio_write:
 	.ascii	"__INT64_C(c) c ## LL\000"
 .LASF699:
 	.ascii	"PRIuFAST8 __PRI8FAST(u)\000"
-.LASF867:
+.LASF871:
 	.ascii	"GPIO_AFRL_AFRL2_BIT 8\000"
 .LASF190:
 	.ascii	"__LDBL_MIN__ 2.2250738585072014e-308L\000"
@@ -5116,7 +5136,7 @@ gpio_write:
 	.ascii	"__ACCUM_IBIT__ 16\000"
 .LASF509:
 	.ascii	"unsigned\000"
-.LASF895:
+.LASF899:
 	.ascii	"PUPDR\000"
 .LASF835:
 	.ascii	"SCNuMAX __SCNMAX(u)\000"
@@ -5126,7 +5146,7 @@ gpio_write:
 	.ascii	"_ATTRIBUTE(attrs) __attribute__ (attrs)\000"
 .LASF359:
 	.ascii	"__UDA_IBIT__ 32\000"
-.LASF906:
+.LASF910:
 	.ascii	"mode\000"
 .LASF586:
 	.ascii	"INTPTR_MAX (__INTPTR_MAX__)\000"
@@ -5140,7 +5160,7 @@ gpio_write:
 	.ascii	"__UHQ_FBIT__ 16\000"
 .LASF443:
 	.ascii	"__ARM_FEATURE_COPROC\000"
-.LASF903:
+.LASF907:
 	.ascii	"GPIO_MODE_ANALOG\000"
 .LASF177:
 	.ascii	"__DBL_HAS_INFINITY__ 1\000"
@@ -5178,7 +5198,7 @@ gpio_write:
 	.ascii	"__FAST8 \000"
 .LASF496:
 	.ascii	"__XSI_VISIBLE 0\000"
-.LASF896:
+.LASF900:
 	.ascii	"BSRR\000"
 .LASF794:
 	.ascii	"PRIu64 __PRI64(u)\000"
@@ -5266,7 +5286,7 @@ gpio_write:
 	.ascii	"PRIx32 __PRI32(x)\000"
 .LASF278:
 	.ascii	"__LLFRACT_MIN__ (-0.5LLR-0.5LLR)\000"
-.LASF890:
+.LASF894:
 	.ascii	"uint32_t\000"
 .LASF689:
 	.ascii	"PRIxLEAST8 __PRI8LEAST(x)\000"
@@ -5314,13 +5334,13 @@ gpio_write:
 	.ascii	"__INT_LEAST16_TYPE__ short int\000"
 .LASF326:
 	.ascii	"__QQ_FBIT__ 7\000"
-.LASF875:
+.LASF879:
 	.ascii	"PINNUM(pin) (pin & 0b1111)\000"
 .LASF768:
 	.ascii	"PRIXLEAST32 __PRI32LEAST(X)\000"
 .LASF171:
 	.ascii	"__DBL_MAX__ ((double)1.7976931348623157e+308L)\000"
-.LASF880:
+.LASF884:
 	.ascii	"short unsigned int\000"
 .LASF276:
 	.ascii	"__LLFRACT_FBIT__ 63\000"
@@ -5368,7 +5388,7 @@ gpio_write:
 	.ascii	"__SCN64LEAST(x) __LEAST64 __STRINGIFY(x)\000"
 .LASF280:
 	.ascii	"__LLFRACT_EPSILON__ 0x1P-63LLR\000"
-.LASF910:
+.LASF914:
 	.ascii	"/home/alex/code/own/stm32-falling-sand\000"
 .LASF249:
 	.ascii	"__SFRACT_MAX__ 0X7FP-7HR\000"
diff --git a/build/gpio.i b/build/gpio.i
index c3ed08a..0cab24a 100644
--- a/build/gpio.i
+++ b/build/gpio.i
@@ -2003,13 +2003,21 @@ struct gpio {
 #define GPIOA ((struct gpio *) GPIOA_BASE_ADDR)
 
 
-#define GPIO_MODER_MODER3_BIT 7
+#define GPIO_MODER_AF_MODE (0b10)
+
+#define GPIO_MODER_MODER8_BIT 16
+#define GPIO_MODER_MODER8_MASK (0b11)
+
+#define GPIO_MODER_MODER3_BIT 6
 #define GPIO_MODER_MODER3_MASK (0b11)
-#define GPIO_MODER_MODER3_AF (0b10)
 
 #define GPIO_MODER_MODER2_BIT 4
 #define GPIO_MODER_MODER2_MASK (0b11)
-#define GPIO_MODER_MODER2_AF (0b10)
+
+
+#define GPIO_AFRH_AFRH8_BIT 0
+#define GPIO_AFRH_AFRH8_MASK (0b1111)
+#define GPIO_AFRH_AFRH8_MCO_1 (0b0000)
 
 
 #define GPIO_AFRL_AFRL3_BIT 12
@@ -2044,9 +2052,9 @@ typedef enum {
 
 void gpio_set_mode(uint16_t pin, GPIO_MODE mode);
 void gpio_write(uint16_t pin, 
-# 64 "src/gpio.h" 3 4
+# 72 "src/gpio.h" 3 4
                              _Bool 
-# 64 "src/gpio.h"
+# 72 "src/gpio.h"
                                   val);
 # 5 "src/gpio.c" 2
 
diff --git a/build/gpio.o b/build/gpio.o
index 7613394..f5ee649 100644
Binary files a/build/gpio.o and b/build/gpio.o differ
diff --git a/build/main.S b/build/main.S
index e25b4ba..6e5ff95 100644
--- a/build/main.S
+++ b/build/main.S
@@ -61,163 +61,149 @@ system_clock_init:
 	ldr	r3, [r3]
 	ldr	r2, .L5
 	.loc 1 22 38
-	orr	r3, r3, #65536
+	bic	r3, r3, #1
 	str	r3, [r2]
-	.loc 1 26 9
-	nop
-.L2:
-	.loc 1 26 42 discriminator 1
-	ldr	r3, .L5
-	ldr	r3, [r3]
-	.loc 1 26 47 discriminator 1
-	and	r3, r3, #131072
-	.loc 1 26 10 discriminator 1
-	cmp	r3, #0
-	beq	.L2
-	.loc 1 30 33
+	.loc 1 34 33
 	ldr	r3, .L5
 	ldr	r3, [r3]
 	ldr	r2, .L5
-	.loc 1 30 38
+	.loc 1 34 38
+	orr	r3, r3, #65536
+	str	r3, [r2]
+	.loc 1 37 33
+	ldr	r3, .L5
+	ldr	r3, [r3]
+	ldr	r2, .L5
+	.loc 1 37 38
+	orr	r3, r3, #524288
+	str	r3, [r2]
+	.loc 1 41 9
+	nop
+.L2:
+	.loc 1 41 42 discriminator 1
+	ldr	r3, .L5
+	ldr	r3, [r3]
+	.loc 1 41 47 discriminator 1
+	and	r3, r3, #131072
+	.loc 1 41 10 discriminator 1
+	cmp	r3, #0
+	beq	.L2
+	.loc 1 45 33
+	ldr	r3, .L5
+	ldr	r3, [r3]
+	ldr	r2, .L5
+	.loc 1 45 38
 	bic	r3, r3, #16777216
 	str	r3, [r2]
-	.loc 1 33 33
+	.loc 1 49 33
 	ldr	r3, .L5
 	ldr	r3, [r3, #4]
 	ldr	r2, .L5
-	.loc 1 33 43
+	.loc 1 49 43
 	orr	r3, r3, #4194304
 	str	r3, [r2, #4]
-	.loc 1 36 33
+	.loc 1 52 33
 	ldr	r3, .L5
 	ldr	r2, [r3, #4]
 	ldr	r1, .L5
-	.loc 1 36 43
+	.loc 1 52 43
 	ldr	r3, .L5+8
 	orrs	r3, r3, r2
 	str	r3, [r1, #4]
-	.loc 1 39 33
+	.loc 1 55 33
 	ldr	r3, .L5
 	ldr	r3, [r3, #8]
 	ldr	r2, .L5
-	.loc 1 39 40
+	.loc 1 55 40
 	bic	r3, r3, #240
 	str	r3, [r2, #8]
-	.loc 1 40 33
+	.loc 1 56 33
 	ldr	r3, .L5
 	ldr	r2, .L5
 	ldr	r3, [r3, #8]
-	.loc 1 40 40
+	.loc 1 56 40
 	str	r3, [r2, #8]
-	.loc 1 43 33
+	.loc 1 59 33
 	ldr	r3, .L5
 	ldr	r3, [r3, #8]
 	ldr	r2, .L5
-	.loc 1 43 40
+	.loc 1 59 40
 	bic	r3, r3, #7168
 	str	r3, [r2, #8]
-	.loc 1 44 33
+	.loc 1 60 33
 	ldr	r3, .L5
 	ldr	r3, [r3, #8]
 	ldr	r2, .L5
-	.loc 1 44 40
+	.loc 1 60 40
 	orr	r3, r3, #4096
 	str	r3, [r2, #8]
-	.loc 1 47 33
-	ldr	r3, .L5
-	ldr	r3, [r3, #8]
-	ldr	r2, .L5
-	.loc 1 47 40
-	bic	r3, r3, #57344
-	str	r3, [r2, #8]
-	.loc 1 48 33
-	ldr	r3, .L5
-	ldr	r2, .L5
-	ldr	r3, [r3, #8]
-	.loc 1 48 40
-	str	r3, [r2, #8]
-	.loc 1 51 33
-	ldr	r3, .L5
-	ldr	r3, [r3]
-	ldr	r2, .L5
-	.loc 1 51 38
-	orr	r3, r3, #16777216
-	str	r3, [r2]
-	.loc 1 55 9
-	nop
-.L3:
-	.loc 1 55 42 discriminator 1
-	ldr	r3, .L5
-	ldr	r3, [r3]
-	.loc 1 55 47 discriminator 1
-	and	r3, r3, #131072
-	.loc 1 55 10 discriminator 1
-	cmp	r3, #0
-	beq	.L3
-	.loc 1 58 35
-	ldr	r3, .L5+12
-	ldr	r3, [r3]
-	ldr	r2, .L5+12
-	.loc 1 58 41
-	orr	r3, r3, #1024
-	str	r3, [r2]
-	.loc 1 59 35
-	ldr	r3, .L5+12
-	ldr	r3, [r3]
-	ldr	r2, .L5+12
-	.loc 1 59 41
-	orr	r3, r3, #512
-	str	r3, [r2]
-	.loc 1 62 35
-	ldr	r3, .L5+12
-	ldr	r3, [r3]
-	ldr	r2, .L5+12
-	.loc 1 62 41
-	bic	r3, r3, #15
-	str	r3, [r2]
 	.loc 1 63 33
 	ldr	r3, .L5
 	ldr	r3, [r3, #8]
 	ldr	r2, .L5
 	.loc 1 63 40
-	orr	r3, r3, #272
-	orr	r3, r3, #1
+	bic	r3, r3, #57344
 	str	r3, [r2, #8]
-	.loc 1 66 33
+	.loc 1 64 33
 	ldr	r3, .L5
-	ldr	r3, [r3, #8]
 	ldr	r2, .L5
-	.loc 1 66 40
-	bic	r3, r3, #3
+	ldr	r3, [r3, #8]
+	.loc 1 64 40
 	str	r3, [r2, #8]
 	.loc 1 67 33
 	ldr	r3, .L5
-	ldr	r3, [r3, #8]
-	ldr	r2, .L5
-	.loc 1 67 40
-	orr	r3, r3, #2
-	str	r3, [r2, #8]
-	.loc 1 71 9
-	nop
-.L4:
-	.loc 1 71 42 discriminator 1
-	ldr	r3, .L5
-	ldr	r3, [r3, #8]
-	.loc 1 71 49 discriminator 1
-	lsrs	r3, r3, #2
-	.loc 1 71 55 discriminator 1
-	and	r3, r3, #3
-	.loc 1 71 65 discriminator 1
-	cmp	r3, #2
-	bne	.L4
-	.loc 1 74 33
-	ldr	r3, .L5
 	ldr	r3, [r3]
 	ldr	r2, .L5
-	.loc 1 74 38
-	bic	r3, r3, #1
+	.loc 1 67 38
+	orr	r3, r3, #16777216
 	str	r3, [r2]
-	.loc 1 75 1
+	.loc 1 71 9
+	nop
+.L3:
+	.loc 1 71 42 discriminator 1
+	ldr	r3, .L5
+	ldr	r3, [r3]
+	.loc 1 71 47 discriminator 1
+	and	r3, r3, #33554432
+	.loc 1 71 10 discriminator 1
+	cmp	r3, #0
+	beq	.L3
+	.loc 1 74 35
+	ldr	r3, .L5+12
+	ldr	r3, [r3]
+	ldr	r2, .L5+12
+	.loc 1 74 41
+	orr	r3, r3, #1024
+	str	r3, [r2]
+	.loc 1 75 35
+	ldr	r3, .L5+12
+	ldr	r3, [r3]
+	ldr	r2, .L5+12
+	.loc 1 75 41
+	orr	r3, r3, #512
+	str	r3, [r2]
+	.loc 1 83 33
+	ldr	r3, .L5
+	ldr	r3, [r3, #8]
+	ldr	r2, .L5
+	.loc 1 83 40
+	orr	r3, r3, #2
+	str	r3, [r2, #8]
+	.loc 1 87 9
+	nop
+.L4:
+	.loc 1 87 42 discriminator 1
+	ldr	r3, .L5
+	ldr	r3, [r3, #8]
+	.loc 1 87 49 discriminator 1
+	lsrs	r3, r3, #2
+	.loc 1 87 55 discriminator 1
+	and	r3, r3, #3
+	.loc 1 87 65 discriminator 1
+	cmp	r3, #2
+	bne	.L4
+	.loc 1 88 1
+	nop
 	nop
 	mov	sp, r7
 	.cfi_def_cfa_register 13
@@ -231,7 +217,7 @@ system_clock_init:
 .L5:
 	.word	1073887232
 	.word	1073770496
-	.word	67252505
+	.word	67252249
 	.word	1073888256
 	.cfi_endproc
 .LFE0:
@@ -239,7 +225,7 @@ system_clock_init:
 	.section	.rodata
 	.align	2
 .LC0:
-	.ascii	"hello, world\012\000"
+	.ascii	"hello, world!\012\000"
 	.section	.text.main,"ax",%progbits
 	.align	1
 	.global	main
@@ -249,7 +235,7 @@ system_clock_init:
 	.type	main, %function
 main:
 .LFB1:
-	.loc 1 77 16
+	.loc 1 90 16
 	.cfi_startproc
 	@ args = 0, pretend = 0, frame = 8
 	@ frame_needed = 1, uses_anonymous_args = 0
@@ -261,60 +247,60 @@ main:
 	.cfi_def_cfa_offset 16
 	add	r7, sp, #0
 	.cfi_def_cfa_register 7
-	.loc 1 78 3
+	.loc 1 91 3
 	bl	system_clock_init
-	.loc 1 79 3
+	.loc 1 92 3
 	bl	tim4_init
-	.loc 1 80 3
+	.loc 1 93 3
 	bl	usart2_init
-	.loc 1 82 3
+	.loc 1 95 3
 	bl	tim4_start
-	.loc 1 83 3
+	.loc 1 96 3
 	bl	usart2_start
-	.loc 1 85 12
+	.loc 1 98 12
 	movw	r3, #525
 	strh	r3, [r7, #2]	@ movhi
-	.loc 1 86 33
+	.loc 1 99 33
 	ldr	r3, .L10
 	ldr	r3, [r3, #48]
-	.loc 1 86 57
+	.loc 1 99 57
 	ldrh	r2, [r7, #2]
 	lsrs	r2, r2, #8
 	uxth	r2, r2
 	mov	r1, r2
-	.loc 1 86 49
+	.loc 1 99 49
 	movs	r2, #1
 	lsls	r2, r2, r1
 	mov	r1, r2
-	.loc 1 86 33
+	.loc 1 99 33
 	ldr	r2, .L10
-	.loc 1 86 43
+	.loc 1 99 43
 	orrs	r3, r3, r1
 	str	r3, [r2, #48]
-	.loc 1 87 3
+	.loc 1 100 3
 	ldrh	r3, [r7, #2]
 	movs	r1, #1
 	mov	r0, r3
 	bl	gpio_set_mode
-	.loc 1 89 54
+	.loc 1 102 54
 	ldr	r3, .L10+4
 	ldr	r3, [r3, #36]
-	.loc 1 89 12
+	.loc 1 102 12
 	strh	r3, [r7, #6]	@ movhi
-	.loc 1 90 7
+	.loc 1 103 7
 	movs	r3, #0
 	strb	r3, [r7, #5]
 .L9:
-	.loc 1 92 39
+	.loc 1 105 39
 	ldr	r3, .L10+4
 	ldr	r2, [r3, #36]
-	.loc 1 92 45
+	.loc 1 105 45
 	ldrh	r3, [r7, #6]
 	subs	r3, r2, r3
-	.loc 1 92 5
+	.loc 1 105 5
 	cmp	r3, #249
 	bls	.L9
-	.loc 1 93 3
+	.loc 1 106 3
 	ldrb	r3, [r7, #5]	@ zero_extendqisi2
 	cmp	r3, #0
 	ite	ne
@@ -323,26 +309,26 @@ main:
 	uxtb	r3, r3
 	eor	r3, r3, #1
 	uxtb	r3, r3
-	.loc 1 93 10
+	.loc 1 106 10
 	strb	r3, [r7, #5]
 	ldrb	r3, [r7, #5]
 	and	r3, r3, #1
 	strb	r3, [r7, #5]
-	.loc 1 94 3
+	.loc 1 107 3
 	ldrb	r2, [r7, #5]	@ zero_extendqisi2
 	ldrh	r3, [r7, #2]
 	mov	r1, r2
 	mov	r0, r3
 	bl	gpio_write
-	.loc 1 96 3
+	.loc 1 109 3
 	ldr	r0, .L10+8
 	bl	usart2_write
-	.loc 1 98 45
+	.loc 1 111 45
 	ldr	r3, .L10+4
 	ldr	r3, [r3, #36]
-	.loc 1 98 11
+	.loc 1 111 11
 	strh	r3, [r7, #6]	@ movhi
-	.loc 1 92 5
+	.loc 1 105 5
 	b	.L9
 .L11:
 	.align	2
@@ -371,10 +357,10 @@ main:
 	.byte	0x4
 	.4byte	.Ldebug_abbrev0
 	.uleb128 0xd
-	.4byte	.LASF1044
+	.4byte	.LASF1061
 	.byte	0x1d
-	.4byte	.LASF1045
-	.4byte	.LASF1046
+	.4byte	.LASF1062
+	.4byte	.LASF1063
 	.4byte	.LLRL0
 	.4byte	0
 	.4byte	.Ldebug_line0
@@ -382,17 +368,17 @@ main:
 	.uleb128 0x3
 	.byte	0x1
 	.byte	0x6
-	.4byte	.LASF975
+	.4byte	.LASF992
 	.uleb128 0x3
 	.byte	0x1
 	.byte	0x8
-	.4byte	.LASF976
+	.4byte	.LASF993
 	.uleb128 0x3
 	.byte	0x2
 	.byte	0x5
-	.4byte	.LASF977
+	.4byte	.LASF994
 	.uleb128 0x4
-	.4byte	.LASF980
+	.4byte	.LASF997
 	.byte	0x2
 	.byte	0x39
 	.byte	0x1c
@@ -400,13 +386,13 @@ main:
 	.uleb128 0x3
 	.byte	0x2
 	.byte	0x7
-	.4byte	.LASF978
+	.4byte	.LASF995
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x5
-	.4byte	.LASF979
+	.4byte	.LASF996
 	.uleb128 0x4
-	.4byte	.LASF981
+	.4byte	.LASF998
 	.byte	0x2
 	.byte	0x4f
 	.byte	0x1b
@@ -414,15 +400,15 @@ main:
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF982
+	.4byte	.LASF999
 	.uleb128 0x3
 	.byte	0x8
 	.byte	0x5
-	.4byte	.LASF983
+	.4byte	.LASF1000
 	.uleb128 0x3
 	.byte	0x8
 	.byte	0x7
-	.4byte	.LASF984
+	.4byte	.LASF1001
 	.uleb128 0xe
 	.byte	0x4
 	.byte	0x5
@@ -430,15 +416,15 @@ main:
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF985
+	.4byte	.LASF1002
 	.uleb128 0x4
-	.4byte	.LASF986
+	.4byte	.LASF1003
 	.byte	0x3
 	.byte	0x24
 	.byte	0x14
 	.4byte	0x3f
 	.uleb128 0x4
-	.4byte	.LASF987
+	.4byte	.LASF1004
 	.byte	0x3
 	.byte	0x30
 	.byte	0x14
@@ -457,13 +443,13 @@ main:
 	.4byte	0xa0
 	.byte	0
 	.uleb128 0x1
-	.4byte	.LASF988
+	.4byte	.LASF1005
 	.byte	0x4
 	.byte	0x8
 	.4byte	0xa0
 	.byte	0x4
 	.uleb128 0x1
-	.4byte	.LASF989
+	.4byte	.LASF1006
 	.byte	0x4
 	.byte	0x9
 	.4byte	0xa0
@@ -475,115 +461,115 @@ main:
 	.4byte	0xa0
 	.byte	0xc
 	.uleb128 0x1
-	.4byte	.LASF990
+	.4byte	.LASF1007
 	.byte	0x4
 	.byte	0xb
 	.4byte	0xa0
 	.byte	0x10
 	.uleb128 0x1
-	.4byte	.LASF991
+	.4byte	.LASF1008
 	.byte	0x4
 	.byte	0xc
 	.4byte	0xa0
 	.byte	0x14
 	.uleb128 0x1
-	.4byte	.LASF992
+	.4byte	.LASF1009
 	.byte	0x4
 	.byte	0xd
 	.4byte	0x210
 	.byte	0x18
 	.uleb128 0x1
-	.4byte	.LASF993
+	.4byte	.LASF1010
 	.byte	0x4
 	.byte	0xe
 	.4byte	0xa0
 	.byte	0x20
 	.uleb128 0x1
-	.4byte	.LASF994
+	.4byte	.LASF1011
 	.byte	0x4
 	.byte	0xf
 	.4byte	0xa0
 	.byte	0x24
 	.uleb128 0x1
-	.4byte	.LASF995
+	.4byte	.LASF1012
 	.byte	0x4
 	.byte	0x10
 	.4byte	0x210
 	.byte	0x28
 	.uleb128 0x1
-	.4byte	.LASF996
+	.4byte	.LASF1013
 	.byte	0x4
 	.byte	0x11
 	.4byte	0xa0
 	.byte	0x30
 	.uleb128 0x1
-	.4byte	.LASF997
+	.4byte	.LASF1014
 	.byte	0x4
 	.byte	0x12
 	.4byte	0xa0
 	.byte	0x34
 	.uleb128 0x1
-	.4byte	.LASF998
+	.4byte	.LASF1015
 	.byte	0x4
 	.byte	0x13
 	.4byte	0x210
 	.byte	0x38
 	.uleb128 0x1
-	.4byte	.LASF999
+	.4byte	.LASF1016
 	.byte	0x4
 	.byte	0x14
 	.4byte	0xa0
 	.byte	0x40
 	.uleb128 0x1
-	.4byte	.LASF1000
+	.4byte	.LASF1017
 	.byte	0x4
 	.byte	0x15
 	.4byte	0xa0
 	.byte	0x44
 	.uleb128 0x1
-	.4byte	.LASF1001
+	.4byte	.LASF1018
 	.byte	0x4
 	.byte	0x16
 	.4byte	0x210
 	.byte	0x48
 	.uleb128 0x1
-	.4byte	.LASF1002
+	.4byte	.LASF1019
 	.byte	0x4
 	.byte	0x17
 	.4byte	0xa0
 	.byte	0x50
 	.uleb128 0x1
-	.4byte	.LASF1003
+	.4byte	.LASF1020
 	.byte	0x4
 	.byte	0x18
 	.4byte	0xa0
 	.byte	0x54
 	.uleb128 0x1
-	.4byte	.LASF1004
+	.4byte	.LASF1021
 	.byte	0x4
 	.byte	0x19
 	.4byte	0x210
 	.byte	0x58
 	.uleb128 0x1
-	.4byte	.LASF1005
+	.4byte	.LASF1022
 	.byte	0x4
 	.byte	0x1a
 	.4byte	0xa0
 	.byte	0x60
 	.uleb128 0x1
-	.4byte	.LASF1006
+	.4byte	.LASF1023
 	.byte	0x4
 	.byte	0x1b
 	.4byte	0xa0
 	.byte	0x64
 	.uleb128 0x1
-	.4byte	.LASF1007
+	.4byte	.LASF1024
 	.byte	0x4
 	.byte	0x1c
 	.4byte	0x210
 	.byte	0x68
 	.uleb128 0x1
-	.4byte	.LASF1008
+	.4byte	.LASF1025
 	.byte	0x4
 	.byte	0x1d
 	.4byte	0xa0
@@ -595,25 +581,25 @@ main:
 	.4byte	0xa0
 	.byte	0x74
 	.uleb128 0x1
-	.4byte	.LASF1009
+	.4byte	.LASF1026
 	.byte	0x4
 	.byte	0x1f
 	.4byte	0x210
 	.byte	0x78
 	.uleb128 0x1
-	.4byte	.LASF1010
+	.4byte	.LASF1027
 	.byte	0x4
 	.byte	0x20
 	.4byte	0xa0
 	.byte	0x80
 	.uleb128 0x1
-	.4byte	.LASF1011
+	.4byte	.LASF1028
 	.byte	0x4
 	.byte	0x21
 	.4byte	0xa0
 	.byte	0x84
 	.uleb128 0x1
-	.4byte	.LASF1012
+	.4byte	.LASF1029
 	.byte	0x4
 	.byte	0x22
 	.4byte	0xa0
@@ -633,30 +619,30 @@ main:
 	.byte	0x1
 	.4byte	0x31
 	.byte	0x5
-	.byte	0x38
+	.byte	0x40
 	.byte	0xe
 	.4byte	0x23c
 	.uleb128 0x6
-	.4byte	.LASF1013
+	.4byte	.LASF1030
 	.byte	0
 	.uleb128 0x6
-	.4byte	.LASF1014
+	.4byte	.LASF1031
 	.byte	0x1
 	.uleb128 0x6
-	.4byte	.LASF1015
+	.4byte	.LASF1032
 	.byte	0x2
 	.uleb128 0x6
-	.4byte	.LASF1016
+	.4byte	.LASF1033
 	.byte	0x3
 	.byte	0
 	.uleb128 0x4
-	.4byte	.LASF1017
+	.4byte	.LASF1034
 	.byte	0x5
-	.byte	0x3d
+	.byte	0x45
 	.byte	0x3
 	.4byte	0x215
 	.uleb128 0xb
-	.4byte	.LASF1018
+	.4byte	.LASF1035
 	.byte	0x18
 	.byte	0x6
 	.4byte	0x29a
@@ -667,13 +653,13 @@ main:
 	.4byte	0xa0
 	.byte	0
 	.uleb128 0x1
-	.4byte	.LASF1019
+	.4byte	.LASF1036
 	.byte	0x6
 	.byte	0x8
 	.4byte	0xa0
 	.byte	0x4
 	.uleb128 0x1
-	.4byte	.LASF1020
+	.4byte	.LASF1037
 	.byte	0x6
 	.byte	0x9
 	.4byte	0xa0
@@ -691,7 +677,7 @@ main:
 	.4byte	0xa0
 	.byte	0x10
 	.uleb128 0x1
-	.4byte	.LASF1021
+	.4byte	.LASF1038
 	.byte	0x6
 	.byte	0xc
 	.4byte	0xa0
@@ -716,7 +702,7 @@ main:
 	.byte	0x4
 	.byte	0
 	.uleb128 0xb
-	.4byte	.LASF1022
+	.4byte	.LASF1039
 	.byte	0x50
 	.byte	0x8
 	.4byte	0x3b8
@@ -733,13 +719,13 @@ main:
 	.4byte	0xa0
 	.byte	0x4
 	.uleb128 0x1
-	.4byte	.LASF1023
+	.4byte	.LASF1040
 	.byte	0x8
 	.byte	0x9
 	.4byte	0xa0
 	.byte	0x8
 	.uleb128 0x1
-	.4byte	.LASF1024
+	.4byte	.LASF1041
 	.byte	0x8
 	.byte	0xa
 	.4byte	0xa0
@@ -757,19 +743,19 @@ main:
 	.4byte	0xa0
 	.byte	0x14
 	.uleb128 0x1
-	.4byte	.LASF1025
+	.4byte	.LASF1042
 	.byte	0x8
 	.byte	0xd
 	.4byte	0xa0
 	.byte	0x18
 	.uleb128 0x1
-	.4byte	.LASF1026
+	.4byte	.LASF1043
 	.byte	0x8
 	.byte	0xe
 	.4byte	0xa0
 	.byte	0x1c
 	.uleb128 0x1
-	.4byte	.LASF1027
+	.4byte	.LASF1044
 	.byte	0x8
 	.byte	0xf
 	.4byte	0xa0
@@ -799,31 +785,31 @@ main:
 	.4byte	0xa0
 	.byte	0x30
 	.uleb128 0x1
-	.4byte	.LASF1028
+	.4byte	.LASF1045
 	.byte	0x8
 	.byte	0x14
 	.4byte	0xa0
 	.byte	0x34
 	.uleb128 0x1
-	.4byte	.LASF1029
+	.4byte	.LASF1046
 	.byte	0x8
 	.byte	0x15
 	.4byte	0xa0
 	.byte	0x38
 	.uleb128 0x1
-	.4byte	.LASF1030
+	.4byte	.LASF1047
 	.byte	0x8
 	.byte	0x16
 	.4byte	0xa0
 	.byte	0x3c
 	.uleb128 0x1
-	.4byte	.LASF1031
+	.4byte	.LASF1048
 	.byte	0x8
 	.byte	0x17
 	.4byte	0xa0
 	.byte	0x40
 	.uleb128 0x1
-	.4byte	.LASF1032
+	.4byte	.LASF1049
 	.byte	0x8
 	.byte	0x18
 	.4byte	0xa0
@@ -835,14 +821,14 @@ main:
 	.4byte	0xa0
 	.byte	0x48
 	.uleb128 0x1
-	.4byte	.LASF1033
+	.4byte	.LASF1050
 	.byte	0x8
 	.byte	0x1a
 	.4byte	0xa0
 	.byte	0x4c
 	.byte	0
 	.uleb128 0x8
-	.4byte	.LASF1034
+	.4byte	.LASF1051
 	.byte	0x9
 	.byte	0x3d
 	.4byte	0x3c9
@@ -857,9 +843,9 @@ main:
 	.byte	0x8
 	.4byte	.LASF510
 	.uleb128 0x8
-	.4byte	.LASF1035
+	.4byte	.LASF1052
 	.byte	0x5
-	.byte	0x40
+	.byte	0x48
 	.4byte	0x3ec
 	.uleb128 0x5
 	.4byte	0x88
@@ -869,11 +855,11 @@ main:
 	.uleb128 0x3
 	.byte	0x1
 	.byte	0x2
-	.4byte	.LASF1036
+	.4byte	.LASF1053
 	.uleb128 0x8
-	.4byte	.LASF1037
+	.4byte	.LASF1054
 	.byte	0x5
-	.byte	0x3f
+	.byte	0x47
 	.4byte	0x409
 	.uleb128 0x5
 	.4byte	0x88
@@ -881,25 +867,25 @@ main:
 	.4byte	0x23c
 	.byte	0
 	.uleb128 0x7
-	.4byte	.LASF1038
+	.4byte	.LASF1055
 	.byte	0x9
 	.byte	0x3a
 	.uleb128 0x7
-	.4byte	.LASF1039
+	.4byte	.LASF1056
 	.byte	0x8
 	.byte	0x24
 	.uleb128 0x7
-	.4byte	.LASF1040
+	.4byte	.LASF1057
 	.byte	0x9
 	.byte	0x39
 	.uleb128 0x7
-	.4byte	.LASF1041
+	.4byte	.LASF1058
 	.byte	0x8
 	.byte	0x23
 	.uleb128 0x13
-	.4byte	.LASF1047
+	.4byte	.LASF1064
 	.byte	0x1
-	.byte	0x4d
+	.byte	0x5a
 	.byte	0x5
 	.4byte	0x7a
 	.4byte	.LFB1
@@ -910,23 +896,23 @@ main:
 	.uleb128 0x14
 	.ascii	"led\000"
 	.byte	0x1
-	.byte	0x55
+	.byte	0x62
 	.byte	0xc
 	.4byte	0x88
 	.uleb128 0x2
 	.byte	0x91
 	.sleb128 -14
 	.uleb128 0xc
-	.4byte	.LASF1042
-	.byte	0x59
+	.4byte	.LASF1059
+	.byte	0x66
 	.byte	0xc
 	.4byte	0x88
 	.uleb128 0x2
 	.byte	0x91
 	.sleb128 -10
 	.uleb128 0xc
-	.4byte	.LASF1043
-	.byte	0x5a
+	.4byte	.LASF1060
+	.byte	0x67
 	.byte	0x7
 	.4byte	0x3ec
 	.uleb128 0x2
@@ -934,7 +920,7 @@ main:
 	.sleb128 -11
 	.byte	0
 	.uleb128 0x15
-	.4byte	.LASF1048
+	.4byte	.LASF1065
 	.byte	0x1
 	.byte	0xd
 	.byte	0xd
@@ -2827,7 +2813,7 @@ main:
 	.byte	0x4
 	.byte	0x5
 	.uleb128 0xb
-	.4byte	.LASF974
+	.4byte	.LASF991
 	.byte	0x4
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4._newlib_version.h.4.6d111ab2e95434b664b53815e5c8ccba,comdat
@@ -4107,7 +4093,7 @@ main:
 	.uleb128 0x32
 	.4byte	.LASF854
 	.byte	0
-	.section	.debug_macro,"G",%progbits,wm4.rcc.h.2.723e44a04c73f618b9d2a2287322c677,comdat
+	.section	.debug_macro,"G",%progbits,wm4.rcc.h.2.900c20676b10d3f3230142c4a203d63e,comdat
 .Ldebug_macro15:
 	.2byte	0x5
 	.byte	0
@@ -4139,64 +4125,64 @@ main:
 	.uleb128 0x33
 	.4byte	.LASF863
 	.byte	0x5
-	.uleb128 0x36
+	.uleb128 0x37
 	.4byte	.LASF864
 	.byte	0x5
-	.uleb128 0x37
+	.uleb128 0x38
 	.4byte	.LASF865
 	.byte	0x5
-	.uleb128 0x3a
+	.uleb128 0x3b
 	.4byte	.LASF866
 	.byte	0x5
-	.uleb128 0x3b
+	.uleb128 0x3c
 	.4byte	.LASF867
 	.byte	0x5
-	.uleb128 0x3e
+	.uleb128 0x3f
 	.4byte	.LASF868
 	.byte	0x5
-	.uleb128 0x3f
+	.uleb128 0x40
 	.4byte	.LASF869
 	.byte	0x5
-	.uleb128 0x42
+	.uleb128 0x43
 	.4byte	.LASF870
 	.byte	0x5
-	.uleb128 0x43
+	.uleb128 0x44
 	.4byte	.LASF871
 	.byte	0x5
-	.uleb128 0x44
+	.uleb128 0x47
 	.4byte	.LASF872
 	.byte	0x5
-	.uleb128 0x46
+	.uleb128 0x48
 	.4byte	.LASF873
 	.byte	0x5
-	.uleb128 0x47
+	.uleb128 0x49
 	.4byte	.LASF874
 	.byte	0x5
-	.uleb128 0x49
+	.uleb128 0x4b
 	.4byte	.LASF875
 	.byte	0x5
-	.uleb128 0x4a
+	.uleb128 0x4c
 	.4byte	.LASF876
 	.byte	0x5
-	.uleb128 0x4b
+	.uleb128 0x4d
 	.4byte	.LASF877
 	.byte	0x5
-	.uleb128 0x4d
+	.uleb128 0x4f
 	.4byte	.LASF878
 	.byte	0x5
-	.uleb128 0x4e
+	.uleb128 0x50
 	.4byte	.LASF879
 	.byte	0x5
-	.uleb128 0x4f
+	.uleb128 0x51
 	.4byte	.LASF880
 	.byte	0x5
-	.uleb128 0x51
+	.uleb128 0x53
 	.4byte	.LASF881
 	.byte	0x5
-	.uleb128 0x52
+	.uleb128 0x54
 	.4byte	.LASF882
 	.byte	0x5
-	.uleb128 0x53
+	.uleb128 0x55
 	.4byte	.LASF883
 	.byte	0x5
 	.uleb128 0x57
@@ -4205,142 +4191,196 @@ main:
 	.uleb128 0x58
 	.4byte	.LASF885
 	.byte	0x5
-	.uleb128 0x5b
+	.uleb128 0x59
 	.4byte	.LASF886
 	.byte	0x5
-	.uleb128 0x5c
+	.uleb128 0x5d
 	.4byte	.LASF887
 	.byte	0x5
-	.uleb128 0x5f
+	.uleb128 0x5e
 	.4byte	.LASF888
 	.byte	0x5
-	.uleb128 0x60
+	.uleb128 0x61
 	.4byte	.LASF889
 	.byte	0x5
-	.uleb128 0x63
+	.uleb128 0x62
 	.4byte	.LASF890
 	.byte	0x5
-	.uleb128 0x65
+	.uleb128 0x63
 	.4byte	.LASF891
 	.byte	0x5
-	.uleb128 0x66
+	.uleb128 0x65
 	.4byte	.LASF892
 	.byte	0x5
-	.uleb128 0x69
+	.uleb128 0x66
 	.4byte	.LASF893
 	.byte	0x5
-	.uleb128 0x6b
+	.uleb128 0x68
 	.4byte	.LASF894
 	.byte	0x5
-	.uleb128 0x6c
+	.uleb128 0x69
 	.4byte	.LASF895
 	.byte	0x5
-	.uleb128 0x6f
+	.uleb128 0x6a
 	.4byte	.LASF896
 	.byte	0x5
-	.uleb128 0x71
+	.uleb128 0x6c
 	.4byte	.LASF897
 	.byte	0x5
-	.uleb128 0x72
+	.uleb128 0x6d
 	.4byte	.LASF898
 	.byte	0x5
-	.uleb128 0x73
+	.uleb128 0x70
 	.4byte	.LASF899
 	.byte	0x5
-	.uleb128 0x77
+	.uleb128 0x71
 	.4byte	.LASF900
 	.byte	0x5
-	.uleb128 0x78
+	.uleb128 0x74
 	.4byte	.LASF901
 	.byte	0x5
-	.uleb128 0x7b
+	.uleb128 0x75
 	.4byte	.LASF902
 	.byte	0x5
-	.uleb128 0x7c
+	.uleb128 0x78
 	.4byte	.LASF903
 	.byte	0x5
-	.uleb128 0x7e
+	.uleb128 0x7a
 	.4byte	.LASF904
 	.byte	0x5
-	.uleb128 0x7f
+	.uleb128 0x7b
 	.4byte	.LASF905
 	.byte	0x5
-	.uleb128 0x81
+	.uleb128 0x7e
 	.4byte	.LASF906
 	.byte	0x5
-	.uleb128 0x82
+	.uleb128 0x80
 	.4byte	.LASF907
+	.byte	0x5
+	.uleb128 0x81
+	.4byte	.LASF908
+	.byte	0x5
+	.uleb128 0x84
+	.4byte	.LASF909
+	.byte	0x5
+	.uleb128 0x85
+	.4byte	.LASF909
+	.byte	0x5
+	.uleb128 0x87
+	.4byte	.LASF910
+	.byte	0x5
+	.uleb128 0x88
+	.4byte	.LASF911
+	.byte	0x5
+	.uleb128 0x89
+	.4byte	.LASF912
+	.byte	0x5
+	.uleb128 0x8d
+	.4byte	.LASF913
+	.byte	0x5
+	.uleb128 0x8e
+	.4byte	.LASF914
+	.byte	0x5
+	.uleb128 0x91
+	.4byte	.LASF915
+	.byte	0x5
+	.uleb128 0x92
+	.4byte	.LASF916
+	.byte	0x5
+	.uleb128 0x94
+	.4byte	.LASF917
+	.byte	0x5
+	.uleb128 0x95
+	.4byte	.LASF918
+	.byte	0x5
+	.uleb128 0x97
+	.4byte	.LASF919
+	.byte	0x5
+	.uleb128 0x98
+	.4byte	.LASF920
 	.byte	0
-	.section	.debug_macro,"G",%progbits,wm4.gpio.h.2.482807a1c0512cd436d5862f3edb1adc,comdat
+	.section	.debug_macro,"G",%progbits,wm4.gpio.h.2.bc74b8bd59193b3190f972f5d232b4bf,comdat
 .Ldebug_macro16:
 	.2byte	0x5
 	.byte	0
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF908
-	.byte	0x5
-	.uleb128 0x14
-	.4byte	.LASF909
-	.byte	0x5
-	.uleb128 0x15
-	.4byte	.LASF910
-	.byte	0x5
-	.uleb128 0x18
-	.4byte	.LASF911
-	.byte	0x5
-	.uleb128 0x19
-	.4byte	.LASF912
-	.byte	0x5
-	.uleb128 0x1a
-	.4byte	.LASF913
-	.byte	0x5
-	.uleb128 0x1c
-	.4byte	.LASF914
-	.byte	0x5
-	.uleb128 0x1d
-	.4byte	.LASF915
-	.byte	0x5
-	.uleb128 0x1e
-	.4byte	.LASF916
-	.byte	0x5
-	.uleb128 0x21
-	.4byte	.LASF917
-	.byte	0x5
-	.uleb128 0x22
-	.4byte	.LASF918
-	.byte	0x5
-	.uleb128 0x23
-	.4byte	.LASF919
-	.byte	0x5
-	.uleb128 0x25
-	.4byte	.LASF920
-	.byte	0x5
-	.uleb128 0x26
 	.4byte	.LASF921
 	.byte	0x5
-	.uleb128 0x27
+	.uleb128 0x14
 	.4byte	.LASF922
 	.byte	0x5
-	.uleb128 0x2c
+	.uleb128 0x15
 	.4byte	.LASF923
 	.byte	0x5
-	.uleb128 0x2d
+	.uleb128 0x18
 	.4byte	.LASF924
 	.byte	0x5
-	.uleb128 0x2e
+	.uleb128 0x1a
 	.4byte	.LASF925
 	.byte	0x5
-	.uleb128 0x30
+	.uleb128 0x1b
 	.4byte	.LASF926
 	.byte	0x5
-	.uleb128 0x32
+	.uleb128 0x1d
 	.4byte	.LASF927
 	.byte	0x5
-	.uleb128 0x34
+	.uleb128 0x1e
 	.4byte	.LASF928
 	.byte	0x5
-	.uleb128 0x36
+	.uleb128 0x20
 	.4byte	.LASF929
+	.byte	0x5
+	.uleb128 0x21
+	.4byte	.LASF930
+	.byte	0x5
+	.uleb128 0x24
+	.4byte	.LASF931
+	.byte	0x5
+	.uleb128 0x25
+	.4byte	.LASF932
+	.byte	0x5
+	.uleb128 0x26
+	.4byte	.LASF933
+	.byte	0x5
+	.uleb128 0x29
+	.4byte	.LASF934
+	.byte	0x5
+	.uleb128 0x2a
+	.4byte	.LASF935
+	.byte	0x5
+	.uleb128 0x2b
+	.4byte	.LASF936
+	.byte	0x5
+	.uleb128 0x2d
+	.4byte	.LASF937
+	.byte	0x5
+	.uleb128 0x2e
+	.4byte	.LASF938
+	.byte	0x5
+	.uleb128 0x2f
+	.4byte	.LASF939
+	.byte	0x5
+	.uleb128 0x34
+	.4byte	.LASF940
+	.byte	0x5
+	.uleb128 0x35
+	.4byte	.LASF941
+	.byte	0x5
+	.uleb128 0x36
+	.4byte	.LASF942
+	.byte	0x5
+	.uleb128 0x38
+	.4byte	.LASF943
+	.byte	0x5
+	.uleb128 0x3a
+	.4byte	.LASF944
+	.byte	0x5
+	.uleb128 0x3c
+	.4byte	.LASF945
+	.byte	0x5
+	.uleb128 0x3e
+	.4byte	.LASF946
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4.flash.h.2.51d6f0499046dca8c8d7cee08875e55f,comdat
 .Ldebug_macro17:
@@ -4348,37 +4388,37 @@ main:
 	.byte	0
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF930
+	.4byte	.LASF947
 	.byte	0x5
 	.uleb128 0xf
-	.4byte	.LASF931
+	.4byte	.LASF948
 	.byte	0x5
 	.uleb128 0x10
-	.4byte	.LASF932
+	.4byte	.LASF949
 	.byte	0x5
 	.uleb128 0x14
-	.4byte	.LASF933
+	.4byte	.LASF950
 	.byte	0x5
 	.uleb128 0x15
-	.4byte	.LASF934
+	.4byte	.LASF951
 	.byte	0x5
 	.uleb128 0x18
-	.4byte	.LASF935
+	.4byte	.LASF952
 	.byte	0x5
 	.uleb128 0x19
-	.4byte	.LASF936
+	.4byte	.LASF953
 	.byte	0x5
 	.uleb128 0x1c
-	.4byte	.LASF937
+	.4byte	.LASF954
 	.byte	0x5
 	.uleb128 0x1e
-	.4byte	.LASF938
+	.4byte	.LASF955
 	.byte	0x5
 	.uleb128 0x1f
-	.4byte	.LASF939
+	.4byte	.LASF956
 	.byte	0x5
 	.uleb128 0x20
-	.4byte	.LASF940
+	.4byte	.LASF957
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4.pwr.h.2.b22d01f8fafa27268c4600cc8f787804,comdat
 .Ldebug_macro18:
@@ -4386,25 +4426,25 @@ main:
 	.byte	0
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF941
+	.4byte	.LASF958
 	.byte	0x5
 	.uleb128 0xb
-	.4byte	.LASF942
+	.4byte	.LASF959
 	.byte	0x5
 	.uleb128 0xc
-	.4byte	.LASF943
+	.4byte	.LASF960
 	.byte	0x5
 	.uleb128 0xf
-	.4byte	.LASF944
+	.4byte	.LASF961
 	.byte	0x5
 	.uleb128 0x12
-	.4byte	.LASF945
+	.4byte	.LASF962
 	.byte	0x5
 	.uleb128 0x13
-	.4byte	.LASF946
+	.4byte	.LASF963
 	.byte	0x5
 	.uleb128 0x14
-	.4byte	.LASF947
+	.4byte	.LASF964
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4.timer.h.2.2e929ede818fb0960868f1b0a08a1cbf,comdat
 .Ldebug_macro19:
@@ -4412,19 +4452,19 @@ main:
 	.byte	0
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF948
+	.4byte	.LASF965
 	.byte	0x5
 	.uleb128 0x1d
-	.4byte	.LASF949
+	.4byte	.LASF966
 	.byte	0x5
 	.uleb128 0x1e
-	.4byte	.LASF950
+	.4byte	.LASF967
 	.byte	0x5
 	.uleb128 0x20
-	.4byte	.LASF951
+	.4byte	.LASF968
 	.byte	0x5
 	.uleb128 0x21
-	.4byte	.LASF952
+	.4byte	.LASF969
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4.usart.h.2.c32df0bd7cfa17e6f790f44d3d6388d5,comdat
 .Ldebug_macro20:
@@ -4432,67 +4472,67 @@ main:
 	.byte	0
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF953
-	.byte	0x5
-	.uleb128 0x10
-	.4byte	.LASF954
-	.byte	0x5
-	.uleb128 0x11
-	.4byte	.LASF955
-	.byte	0x5
-	.uleb128 0x15
-	.4byte	.LASF956
-	.byte	0x5
-	.uleb128 0x16
-	.4byte	.LASF957
-	.byte	0x5
-	.uleb128 0x19
-	.4byte	.LASF958
-	.byte	0x5
-	.uleb128 0x1a
-	.4byte	.LASF959
-	.byte	0x5
-	.uleb128 0x1e
-	.4byte	.LASF960
-	.byte	0x5
-	.uleb128 0x1f
-	.4byte	.LASF961
-	.byte	0x5
-	.uleb128 0x23
-	.4byte	.LASF962
-	.byte	0x5
-	.uleb128 0x24
-	.4byte	.LASF963
-	.byte	0x5
-	.uleb128 0x27
-	.4byte	.LASF964
-	.byte	0x5
-	.uleb128 0x28
-	.4byte	.LASF965
-	.byte	0x5
-	.uleb128 0x2b
-	.4byte	.LASF966
-	.byte	0x5
-	.uleb128 0x2c
-	.4byte	.LASF967
-	.byte	0x5
-	.uleb128 0x2f
-	.4byte	.LASF968
-	.byte	0x5
-	.uleb128 0x30
-	.4byte	.LASF969
-	.byte	0x5
-	.uleb128 0x33
 	.4byte	.LASF970
 	.byte	0x5
-	.uleb128 0x34
+	.uleb128 0x10
 	.4byte	.LASF971
 	.byte	0x5
-	.uleb128 0x36
+	.uleb128 0x11
 	.4byte	.LASF972
 	.byte	0x5
-	.uleb128 0x37
+	.uleb128 0x15
 	.4byte	.LASF973
+	.byte	0x5
+	.uleb128 0x16
+	.4byte	.LASF974
+	.byte	0x5
+	.uleb128 0x19
+	.4byte	.LASF975
+	.byte	0x5
+	.uleb128 0x1a
+	.4byte	.LASF976
+	.byte	0x5
+	.uleb128 0x1e
+	.4byte	.LASF977
+	.byte	0x5
+	.uleb128 0x1f
+	.4byte	.LASF978
+	.byte	0x5
+	.uleb128 0x23
+	.4byte	.LASF979
+	.byte	0x5
+	.uleb128 0x24
+	.4byte	.LASF980
+	.byte	0x5
+	.uleb128 0x27
+	.4byte	.LASF981
+	.byte	0x5
+	.uleb128 0x28
+	.4byte	.LASF982
+	.byte	0x5
+	.uleb128 0x2b
+	.4byte	.LASF983
+	.byte	0x5
+	.uleb128 0x2c
+	.4byte	.LASF984
+	.byte	0x5
+	.uleb128 0x2f
+	.4byte	.LASF985
+	.byte	0x5
+	.uleb128 0x30
+	.4byte	.LASF986
+	.byte	0x5
+	.uleb128 0x33
+	.4byte	.LASF987
+	.byte	0x5
+	.uleb128 0x34
+	.4byte	.LASF988
+	.byte	0x5
+	.uleb128 0x36
+	.4byte	.LASF989
+	.byte	0x5
+	.uleb128 0x37
+	.4byte	.LASF990
 	.byte	0
 	.section	.debug_line,"",%progbits
 .Ldebug_line0:
@@ -4509,7 +4549,7 @@ main:
 	.ascii	"__UHA_FBIT__ 8\000"
 .LASF814:
 	.ascii	"PRIiFAST64 __PRI64FAST(i)\000"
-.LASF976:
+.LASF993:
 	.ascii	"unsigned char\000"
 .LASF225:
 	.ascii	"__FLT64_DENORM_MIN__ 4.9406564584124654e-324F64\000"
@@ -4539,7 +4579,7 @@ main:
 	.ascii	"__WINT_MIN__ 0U\000"
 .LASF90:
 	.ascii	"__INTMAX_MAX__ 0x7fffffffffffffffLL\000"
-.LASF1015:
+.LASF1032:
 	.ascii	"GPIO_MODE_AF\000"
 .LASF335:
 	.ascii	"__TQ_IBIT__ 0\000"
@@ -4551,11 +4591,13 @@ main:
 	.ascii	"__ULACCUM_FBIT__ 32\000"
 .LASF75:
 	.ascii	"__WCHAR_MAX__ 0xffffffffU\000"
+.LASF896:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV2 (0b100)\000"
 .LASF513:
 	.ascii	"__int20__\000"
-.LASF906:
+.LASF919:
 	.ascii	"RCC_APB1ENR_TIM4_BIT 2\000"
-.LASF973:
+.LASF990:
 	.ascii	"USART_BRR_FRACTION_MASK (0b111)\000"
 .LASF18:
 	.ascii	"__SIZEOF_LONG_LONG__ 8\000"
@@ -4567,7 +4609,7 @@ main:
 	.ascii	"__FRACT_MIN__ (-0.5R-0.5R)\000"
 .LASF324:
 	.ascii	"__ULLACCUM_MAX__ 0XFFFFFFFFFFFFFFFFP-32ULLK\000"
-.LASF1018:
+.LASF1035:
 	.ascii	"flash\000"
 .LASF294:
 	.ascii	"__USACCUM_MAX__ 0XFFFFP-8UHK\000"
@@ -4575,7 +4617,7 @@ main:
 	.ascii	"__SFRACT_FBIT__ 7\000"
 .LASF94:
 	.ascii	"__INTMAX_WIDTH__ 64\000"
-.LASF953:
+.LASF970:
 	.ascii	"USART_H_ \000"
 .LASF448:
 	.ascii	"__ARM_FEATURE_BF16_SCALAR_ARITHMETIC\000"
@@ -4585,7 +4627,7 @@ main:
 	.ascii	"__ORDER_PDP_ENDIAN__ 3412\000"
 .LASF34:
 	.ascii	"__SIZE_TYPE__ unsigned int\000"
-.LASF907:
+.LASF920:
 	.ascii	"RCC_APB1ENR_TIM4_ENABLE (1 << RCC_APB1ENR_TIM4_BIT)"
 	.ascii	"\000"
 .LASF620:
@@ -4624,8 +4666,6 @@ main:
 	.ascii	"RCC_BASE_ADDR (0x40023800U)\000"
 .LASF525:
 	.ascii	"__INT8 \"hh\"\000"
-.LASF913:
-	.ascii	"GPIO_MODER_MODER3_AF (0b10)\000"
 .LASF47:
 	.ascii	"__UINT8_TYPE__ unsigned char\000"
 .LASF368:
@@ -4634,7 +4674,7 @@ main:
 	.ascii	"INT_LEAST16_MAX (__INT_LEAST16_MAX__)\000"
 .LASF703:
 	.ascii	"SCNiFAST8 __SCN8FAST(i)\000"
-.LASF909:
+.LASF922:
 	.ascii	"GPIOA_BASE_ADDR (0x40020000U)\000"
 .LASF790:
 	.ascii	"__SCN64FAST(x) __FAST64 __STRINGIFY(x)\000"
@@ -4648,9 +4688,9 @@ main:
 	.ascii	"_LDBL_EQ_DBL 1\000"
 .LASF675:
 	.ascii	"PRIi8 __PRI8(i)\000"
-.LASF936:
+.LASF953:
 	.ascii	"FLASH_ACR_ICEN_ENABLE (1 <<FLASH_ACR_ICEN_BIT)\000"
-.LASF946:
+.LASF963:
 	.ascii	"PWR_CR_VOS_MASK (0b11)\000"
 .LASF62:
 	.ascii	"__INT_FAST64_TYPE__ long long int\000"
@@ -4666,7 +4706,7 @@ main:
 	.ascii	"__SCNPTR(x) __STRINGIFY(x)\000"
 .LASF202:
 	.ascii	"__FLT32_MAX_10_EXP__ 38\000"
-.LASF891:
+.LASF904:
 	.ascii	"RCC_CFGR_HPRE_BIT 4\000"
 .LASF682:
 	.ascii	"SCNo8 __SCN8(o)\000"
@@ -4682,14 +4722,16 @@ main:
 	.ascii	"__need_wchar_t\000"
 .LASF199:
 	.ascii	"__FLT32_MIN_EXP__ (-125)\000"
-.LASF1044:
+.LASF1061:
 	.ascii	"GNU C2X 12.3.1 20230626 -mcpu=cortex-m4 -mthumb -mf"
 	.ascii	"loat-abi=hard -mfpu=fpv4-sp-d16 -march=armv7e-m+fp "
 	.ascii	"-g3 -ggdb -O0 -std=c2x -ffunction-sections -fdata-s"
 	.ascii	"ections -fno-builtin -fno-common\000"
-.LASF917:
+.LASF931:
+	.ascii	"GPIO_AFRH_AFRH8_BIT 0\000"
+.LASF934:
 	.ascii	"GPIO_AFRL_AFRL3_BIT 12\000"
-.LASF864:
+.LASF866:
 	.ascii	"RCC_CR_HSEON_BIT 16\000"
 .LASF595:
 	.ascii	"INT16_MAX (__INT16_MAX__)\000"
@@ -4703,7 +4745,7 @@ main:
 	.ascii	"__int_fast32_t_defined 1\000"
 .LASF133:
 	.ascii	"__INT_FAST64_WIDTH__ 64\000"
-.LASF1033:
+.LASF1050:
 	.ascii	"DMAR\000"
 .LASF659:
 	.ascii	"___int_wchar_t_h \000"
@@ -4719,6 +4761,8 @@ main:
 	.ascii	"__SFRACT_EPSILON__ 0x1P-7HR\000"
 .LASF2:
 	.ascii	"__STDC_UTF_16__ 1\000"
+.LASF893:
+	.ascii	"RCC_CFGR_MCO1_MASK (0b11)\000"
 .LASF113:
 	.ascii	"__INT32_C(c) c ## L\000"
 .LASF27:
@@ -4747,28 +4791,30 @@ main:
 	.ascii	"__PRI32LEAST(x) __LEAST32 __STRINGIFY(x)\000"
 .LASF88:
 	.ascii	"__PTRDIFF_WIDTH__ 32\000"
-.LASF899:
-	.ascii	"RCC_CFGR_SW(clock) ((clock & RCC_CFGR_SW_MASK) << R"
-	.ascii	"CC_CFGR_SW_BIT)\000"
+.LASF957:
+	.ascii	"FLASH_ACR_LATENCY(latency) ((latency & FLASH_ACR_LA"
+	.ascii	"TENCY_MASK) << FLASH_ACR_LATENCY_BIT)\000"
+.LASF891:
+	.ascii	"RCC_CFGR_MCO1_PLL (0b11)\000"
 .LASF134:
 	.ascii	"__UINT_FAST8_MAX__ 0xffffffffU\000"
 .LASF760:
 	.ascii	"SCNo32 __SCN32(o)\000"
 .LASF540:
 	.ascii	"_NOTHROW \000"
-.LASF1028:
+.LASF1045:
 	.ascii	"CCR1\000"
 .LASF633:
 	.ascii	"WCHAR_MAX (__WCHAR_MAX__)\000"
-.LASF1030:
+.LASF1047:
 	.ascii	"CCR3\000"
-.LASF1031:
+.LASF1048:
 	.ascii	"CCR4\000"
 .LASF307:
 	.ascii	"__LACCUM_IBIT__ 32\000"
 .LASF592:
 	.ascii	"INT_LEAST8_MAX (__INT_LEAST8_MAX__)\000"
-.LASF893:
+.LASF906:
 	.ascii	"RCC_CFGR_SWS_PLL (0b10)\000"
 .LASF559:
 	.ascii	"__EXP\000"
@@ -4786,7 +4832,7 @@ main:
 	.ascii	"__INT64 \"ll\"\000"
 .LASF138:
 	.ascii	"__INTPTR_MAX__ 0x7fffffff\000"
-.LASF1003:
+.LASF1020:
 	.ascii	"AHB2LPENR\000"
 .LASF499:
 	.ascii	"__RAND_MAX\000"
@@ -4796,7 +4842,7 @@ main:
 	.ascii	"INT_LEAST64_MIN (-__INT_LEAST64_MAX__ - 1)\000"
 .LASF613:
 	.ascii	"INT_FAST8_MAX (__INT_FAST8_MAX__)\000"
-.LASF903:
+.LASF916:
 	.ascii	"RCC_APB1ENR_PWREN_CLOCK_ENABLE (1 << RCC_APB1ENR_PW"
 	.ascii	"REN_BIT)\000"
 .LASF486:
@@ -4824,12 +4870,12 @@ main:
 	.ascii	"__ACCUM_FBIT__ 15\000"
 .LASF791:
 	.ascii	"PRId64 __PRI64(d)\000"
-.LASF877:
+.LASF880:
 	.ascii	"RCC_PLLCFGR_PLLP(p) ((p & RCC_PLLCFGR_PLLP_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLP_BIT)\000"
 .LASF302:
 	.ascii	"__UACCUM_IBIT__ 16\000"
-.LASF979:
+.LASF996:
 	.ascii	"long int\000"
 .LASF719:
 	.ascii	"SCNd16 __SCN16(d)\000"
@@ -4847,7 +4893,7 @@ main:
 	.ascii	"__FLT32X_EPSILON__ 2.2204460492503131e-16F32x\000"
 .LASF556:
 	.ascii	"___int_least16_t_defined 1\000"
-.LASF883:
+.LASF886:
 	.ascii	"RCC_PLLCFGR_PLLM(m) ((m & RCC_PLLCFGR_PLLM_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLM_BIT)\000"
 .LASF59:
@@ -4862,7 +4908,7 @@ main:
 	.ascii	"__LLFRACT_MIN__ (-0.5LLR-0.5LLR)\000"
 .LASF93:
 	.ascii	"__UINTMAX_C(c) c ## ULL\000"
-.LASF870:
+.LASF872:
 	.ascii	"RCC_PLLCFGR_PLLQ_BIT 24\000"
 .LASF31:
 	.ascii	"__SIZEOF_POINTER__ 4\000"
@@ -4870,10 +4916,8 @@ main:
 	.ascii	"INT_FAST64_MIN (-__INT_FAST64_MAX__ - 1)\000"
 .LASF371:
 	.ascii	"__GCC_ATOMIC_BOOL_LOCK_FREE 2\000"
-.LASF898:
+.LASF911:
 	.ascii	"RCC_CFGR_SW_MASK (0b11)\000"
-.LASF916:
-	.ascii	"GPIO_MODER_MODER2_AF (0b10)\000"
 .LASF432:
 	.ascii	"__ARM_NEON__\000"
 .LASF587:
@@ -4882,7 +4926,7 @@ main:
 	.ascii	"__FLT32_MAX_EXP__ 128\000"
 .LASF824:
 	.ascii	"__PRIMAX(x) __STRINGIFY(ll ##x)\000"
-.LASF1047:
+.LASF1064:
 	.ascii	"main\000"
 .LASF435:
 	.ascii	"__THUMB_INTERWORK__ 1\000"
@@ -4890,7 +4934,7 @@ main:
 	.ascii	"__ULLFRACT_MAX__ 0XFFFFFFFFFFFFFFFFP-64ULLR\000"
 .LASF697:
 	.ascii	"PRIiFAST8 __PRI8FAST(i)\000"
-.LASF961:
+.LASF978:
 	.ascii	"USART_SR_RXNE_READY (1 <<USART_SR_RXNE_BIT)\000"
 .LASF33:
 	.ascii	"__GNUC_WIDE_EXECUTION_CHARSET_NAME \"UTF-32LE\"\000"
@@ -4900,7 +4944,7 @@ main:
 	.ascii	"__CHAR32_TYPE__ long unsigned int\000"
 .LASF429:
 	.ascii	"__ARM_FEATURE_FP16_VECTOR_ARITHMETIC\000"
-.LASF908:
+.LASF921:
 	.ascii	"GPIO_H_ \000"
 .LASF179:
 	.ascii	"__DBL_IS_IEC_60559__ 2\000"
@@ -4912,7 +4956,7 @@ main:
 	.ascii	"__SIZEOF_LONG__ 4\000"
 .LASF753:
 	.ascii	"PRIi32 __PRI32(i)\000"
-.LASF1000:
+.LASF1017:
 	.ascii	"APB2ENR\000"
 .LASF855:
 	.ascii	"RCC_H_ \000"
@@ -4924,11 +4968,11 @@ main:
 	.ascii	"__SIZEOF_DOUBLE__ 8\000"
 .LASF114:
 	.ascii	"__INT_LEAST32_WIDTH__ 32\000"
-.LASF935:
+.LASF952:
 	.ascii	"FLASH_ACR_ICEN_BIT 9\000"
 .LASF815:
 	.ascii	"PRIoFAST64 __PRI64FAST(o)\000"
-.LASF1002:
+.LASF1019:
 	.ascii	"AHB1LPENR\000"
 .LASF406:
 	.ascii	"__ARM_FEATURE_SIMD32 1\000"
@@ -4940,7 +4984,7 @@ main:
 	.ascii	"PRIoLEAST16 __PRI16LEAST(o)\000"
 .LASF458:
 	.ascii	"__NEWLIB__ 4\000"
-.LASF1012:
+.LASF1029:
 	.ascii	"DCKCFGR\000"
 .LASF720:
 	.ascii	"SCNi16 __SCN16(i)\000"
@@ -4950,7 +4994,7 @@ main:
 	.ascii	"__FLT_DECIMAL_DIG__ 9\000"
 .LASF562:
 	.ascii	"_UINT8_T_DECLARED \000"
-.LASF975:
+.LASF992:
 	.ascii	"signed char\000"
 .LASF805:
 	.ascii	"PRIuLEAST64 __PRI64LEAST(u)\000"
@@ -4960,7 +5004,7 @@ main:
 	.ascii	"INTMAX_MIN (-INTMAX_MAX - 1)\000"
 .LASF364:
 	.ascii	"__GNUC_STDC_INLINE__ 1\000"
-.LASF1017:
+.LASF1034:
 	.ascii	"GPIO_MODE\000"
 .LASF256:
 	.ascii	"__FRACT_FBIT__ 15\000"
@@ -4968,11 +5012,13 @@ main:
 	.ascii	"PRIxFAST8 __PRI8FAST(x)\000"
 .LASF320:
 	.ascii	"__LLACCUM_EPSILON__ 0x1P-31LLK\000"
+.LASF975:
+	.ascii	"USART_SR_TC_BIT 6\000"
 .LASF7:
 	.ascii	"__GNUC_PATCHLEVEL__ 1\000"
 .LASF374:
 	.ascii	"__GCC_ATOMIC_CHAR32_T_LOCK_FREE 2\000"
-.LASF871:
+.LASF873:
 	.ascii	"RCC_PLLCFGR_PLLQ_MASK (0b1111)\000"
 .LASF120:
 	.ascii	"__UINT_LEAST16_MAX__ 0xffff\000"
@@ -4984,35 +5030,35 @@ main:
 	.ascii	"_STDBOOL_H \000"
 .LASF219:
 	.ascii	"__FLT64_MAX_10_EXP__ 308\000"
-.LASF921:
+.LASF938:
 	.ascii	"GPIO_AFRL_AFRL2_MASK (0b1111)\000"
-.LASF879:
+.LASF882:
 	.ascii	"RCC_PLLCFGR_PLLN_MASK (0b111111111)\000"
-.LASF992:
+.LASF1009:
 	.ascii	"RESERVED0\000"
-.LASF995:
+.LASF1012:
 	.ascii	"RESERVED1\000"
-.LASF998:
+.LASF1015:
 	.ascii	"RESERVED2\000"
 .LASF3:
 	.ascii	"__STDC_UTF_32__ 1\000"
-.LASF1004:
+.LASF1021:
 	.ascii	"RESERVED4\000"
 .LASF241:
 	.ascii	"__FLT32X_DENORM_MIN__ 4.9406564584124654e-324F32x\000"
-.LASF1009:
+.LASF1026:
 	.ascii	"RESERVED6\000"
 .LASF152:
 	.ascii	"__FLT_MAX_10_EXP__ 38\000"
 .LASF42:
 	.ascii	"__SIG_ATOMIC_TYPE__ int\000"
-.LASF888:
+.LASF901:
 	.ascii	"RCC_CFGR_PPRE1_BIT 10\000"
 .LASF259:
 	.ascii	"__FRACT_MAX__ 0X7FFFP-15R\000"
 .LASF728:
 	.ascii	"PRIxLEAST16 __PRI16LEAST(x)\000"
-.LASF947:
+.LASF964:
 	.ascii	"PWR_CR_VOS(scale) ((scale & PWR_CR_VOS_MASK) << PWR"
 	.ascii	"_CR_VOS_BIT)\000"
 .LASF130:
@@ -5023,11 +5069,11 @@ main:
 	.ascii	"_READ_WRITE_RETURN_TYPE int\000"
 .LASF771:
 	.ascii	"SCNoLEAST32 __SCN32LEAST(o)\000"
-.LASF896:
+.LASF909:
 	.ascii	"RCC_CFGR_SW_PLL (0b10)\000"
 .LASF844:
 	.ascii	"PRIXPTR __PRIPTR(X)\000"
-.LASF951:
+.LASF968:
 	.ascii	"TIM_CR1_CEN_BIT 0\000"
 .LASF797:
 	.ascii	"SCNd64 __SCN64(d)\000"
@@ -5047,17 +5093,17 @@ main:
 	.ascii	"__int_fast64_t_defined 1\000"
 .LASF837:
 	.ascii	"__PRIPTR(x) __STRINGIFY(x)\000"
-.LASF986:
+.LASF1003:
 	.ascii	"uint16_t\000"
 .LASF417:
 	.ascii	"__thumb2__ 1\000"
 .LASF321:
 	.ascii	"__ULLACCUM_FBIT__ 32\000"
-.LASF1036:
+.LASF1053:
 	.ascii	"_Bool\000"
-.LASF902:
+.LASF915:
 	.ascii	"RCC_APB1ENR_PWREN_BIT 28\000"
-.LASF905:
+.LASF918:
 	.ascii	"RCC_APB1ENR_USART2EN_ENABLE (1 << RCC_APB1ENR_USART"
 	.ascii	"2EN_BIT)\000"
 .LASF366:
@@ -5068,23 +5114,23 @@ main:
 	.ascii	"SCNxLEAST64 __SCN64LEAST(x)\000"
 .LASF769:
 	.ascii	"SCNdLEAST32 __SCN32LEAST(d)\000"
-.LASF1001:
+.LASF1018:
 	.ascii	"RESERVED3\000"
 .LASF22:
 	.ascii	"__SIZEOF_LONG_DOUBLE__ 8\000"
-.LASF1007:
+.LASF1024:
 	.ascii	"RESERVED5\000"
-.LASF1025:
+.LASF1042:
 	.ascii	"CCMR1\000"
-.LASF1026:
+.LASF1043:
 	.ascii	"CCMR2\000"
 .LASF36:
 	.ascii	"__WCHAR_TYPE__ unsigned int\000"
-.LASF948:
+.LASF965:
 	.ascii	"TIMER_H_ \000"
 .LASF469:
 	.ascii	"_MB_LEN_MAX 8\000"
-.LASF1014:
+.LASF1031:
 	.ascii	"GPIO_MODE_OUTPUT\000"
 .LASF357:
 	.ascii	"__USA_IBIT__ 16\000"
@@ -5098,9 +5144,9 @@ main:
 	.ascii	"__need_wchar_t \000"
 .LASF66:
 	.ascii	"__UINT_FAST64_TYPE__ long long unsigned int\000"
-.LASF954:
+.LASF971:
 	.ascii	"USART2_BASE_ADDR (0x40004400U)\000"
-.LASF894:
+.LASF907:
 	.ascii	"RCC_CFGR_SWS_BIT 2\000"
 .LASF156:
 	.ascii	"__FLT_MIN__ 1.1754943508222875e-38F\000"
@@ -5118,7 +5164,7 @@ main:
 	.ascii	"__FLT32_IS_IEC_60559__ 2\000"
 .LASF629:
 	.ascii	"SIG_ATOMIC_MAX (__STDINT_EXP(INT_MAX))\000"
-.LASF969:
+.LASF986:
 	.ascii	"USART_CR1_RE_ENABLE (1 << USART_CR1_RE_BIT)\000"
 .LASF724:
 	.ascii	"PRIdLEAST16 __PRI16LEAST(d)\000"
@@ -5128,9 +5174,9 @@ main:
 	.ascii	"__SCN64(x) __INT64 __STRINGIFY(x)\000"
 .LASF646:
 	.ascii	"_GCC_WRAP_STDINT_H \000"
-.LASF980:
-	.ascii	"__uint16_t\000"
 .LASF997:
+	.ascii	"__uint16_t\000"
+.LASF1014:
 	.ascii	"AHB2ENR\000"
 .LASF804:
 	.ascii	"PRIoLEAST64 __PRI64LEAST(o)\000"
@@ -5144,7 +5190,7 @@ main:
 	.ascii	"__UINT8_MAX__ 0xff\000"
 .LASF552:
 	.ascii	"___int16_t_defined 1\000"
-.LASF1022:
+.LASF1039:
 	.ascii	"timer\000"
 .LASF184:
 	.ascii	"__LDBL_MAX_EXP__ 1024\000"
@@ -5156,17 +5202,19 @@ main:
 	.ascii	"__int8_t_defined 1\000"
 .LASF176:
 	.ascii	"__DBL_HAS_DENORM__ 1\000"
+.LASF890:
+	.ascii	"RCC_CFGR_MCO1_HSE (0b10)\000"
 .LASF624:
 	.ascii	"INTMAX_MAX (__INTMAX_MAX__)\000"
 .LASF601:
 	.ascii	"INT32_MAX (__INT32_MAX__)\000"
-.LASF926:
+.LASF943:
 	.ascii	"BIT(x) (1 << x)\000"
 .LASF426:
 	.ascii	"__ARM_FP16_FORMAT_ALTERNATIVE\000"
-.LASF1048:
+.LASF1065:
 	.ascii	"system_clock_init\000"
-.LASF932:
+.LASF949:
 	.ascii	"FLASH ((struct flash *) FLASH_BASE_ADDR)\000"
 .LASF69:
 	.ascii	"__GXX_ABI_VERSION 1017\000"
@@ -5176,15 +5224,15 @@ main:
 	.ascii	"__FLT_DENORM_MIN__ 1.4012984643248171e-45F\000"
 .LASF533:
 	.ascii	"__LEAST8 \"hh\"\000"
-.LASF890:
+.LASF903:
 	.ascii	"RCC_CFGR_HPRE_DIV_NONE 0\000"
 .LASF539:
 	.ascii	"_END_STD_C \000"
 .LASF852:
 	.ascii	"true ((_Bool)+1u)\000"
-.LASF918:
+.LASF935:
 	.ascii	"GPIO_AFRL_AFRL3_MASK (0b1111)\000"
-.LASF937:
+.LASF954:
 	.ascii	"FLASH_ACR_LATENCY_3_WAIT_STATES (0x0111)\000"
 .LASF599:
 	.ascii	"UINT_LEAST16_MAX (__UINT_LEAST16_MAX__)\000"
@@ -5194,13 +5242,13 @@ main:
 	.ascii	"PRIiLEAST16 __PRI16LEAST(i)\000"
 .LASF303:
 	.ascii	"__UACCUM_MIN__ 0.0UK\000"
-.LASF875:
+.LASF878:
 	.ascii	"RCC_PLLCFGR_PLLP_BIT 16\000"
 .LASF157:
 	.ascii	"__FLT_EPSILON__ 1.1920928955078125e-7F\000"
 .LASF297:
 	.ascii	"__ACCUM_IBIT__ 16\000"
-.LASF927:
+.LASF944:
 	.ascii	"PIN(port,num) ((((port) - 'A') << 8) | num)\000"
 .LASF806:
 	.ascii	"PRIxLEAST64 __PRI64LEAST(x)\000"
@@ -5222,7 +5270,7 @@ main:
 	.ascii	"INT_LEAST32_MIN (-__INT_LEAST32_MAX__ - 1)\000"
 .LASF376:
 	.ascii	"__GCC_ATOMIC_SHORT_LOCK_FREE 2\000"
-.LASF868:
+.LASF870:
 	.ascii	"RCC_CR_HSION_BIT 0\000"
 .LASF778:
 	.ascii	"PRIxFAST32 __PRI32FAST(x)\000"
@@ -5240,7 +5288,7 @@ main:
 	.ascii	"__ELF__ 1\000"
 .LASF688:
 	.ascii	"PRIuLEAST8 __PRI8LEAST(u)\000"
-.LASF1008:
+.LASF1025:
 	.ascii	"BDCR\000"
 .LASF853:
 	.ascii	"false ((_Bool)+0u)\000"
@@ -5274,7 +5322,7 @@ main:
 	.ascii	"__FP_FAST_FMAF 1\000"
 .LASF628:
 	.ascii	"SIG_ATOMIC_MIN (-__STDINT_EXP(INT_MAX) - 1)\000"
-.LASF865:
+.LASF867:
 	.ascii	"RCC_CR_HSEON_ON (1 << RCC_CR_HSEON_BIT)\000"
 .LASF564:
 	.ascii	"_INT16_T_DECLARED \000"
@@ -5296,21 +5344,26 @@ main:
 	.ascii	"__ARM_FEATURE_FP16_FML\000"
 .LASF802:
 	.ascii	"PRIdLEAST64 __PRI64LEAST(d)\000"
+.LASF924:
+	.ascii	"GPIO_MODER_AF_MODE (0b10)\000"
 .LASF255:
 	.ascii	"__USFRACT_EPSILON__ 0x1P-8UHR\000"
-.LASF863:
+.LASF865:
 	.ascii	"RCC_CR_HSERDY_READY (1 << RCC_CR_HSERDY_BIT)\000"
 .LASF762:
 	.ascii	"SCNx32 __SCN32(x)\000"
-.LASF989:
+.LASF1006:
 	.ascii	"CFGR\000"
 .LASF557:
 	.ascii	"___int_least32_t_defined 1\000"
 .LASF319:
 	.ascii	"__LLACCUM_MAX__ 0X7FFFFFFFFFFFFFFFP-31LLK\000"
+.LASF912:
+	.ascii	"RCC_CFGR_SW(clock) ((clock & RCC_CFGR_SW_MASK) << R"
+	.ascii	"CC_CFGR_SW_BIT)\000"
 .LASF666:
 	.ascii	"__need_NULL\000"
-.LASF963:
+.LASF980:
 	.ascii	"USART_CR1_OVER8_8 (1 << USART_CR1_OVER8_BIT)\000"
 .LASF363:
 	.ascii	"__USER_LABEL_PREFIX__ \000"
@@ -5324,7 +5377,7 @@ main:
 	.ascii	"INT64_C(x) __INT64_C(x)\000"
 .LASF615:
 	.ascii	"INT_FAST16_MIN (-__INT_FAST16_MAX__ - 1)\000"
-.LASF915:
+.LASF930:
 	.ascii	"GPIO_MODER_MODER2_MASK (0b11)\000"
 .LASF106:
 	.ascii	"__INT_LEAST8_MAX__ 0x7f\000"
@@ -5354,7 +5407,7 @@ main:
 	.ascii	"__PRI8LEAST(x) __LEAST8 __STRINGIFY(x)\000"
 .LASF174:
 	.ascii	"__DBL_EPSILON__ ((double)2.2204460492503131e-16L)\000"
-.LASF1020:
+.LASF1037:
 	.ascii	"OPTKEYR\000"
 .LASF268:
 	.ascii	"__LFRACT_MIN__ (-0.5LR-0.5LR)\000"
@@ -5378,7 +5431,7 @@ main:
 	.ascii	"___int8_t_defined 1\000"
 .LASF248:
 	.ascii	"__SFRACT_MIN__ (-0.5HR-0.5HR)\000"
-.LASF982:
+.LASF999:
 	.ascii	"long unsigned int\000"
 .LASF349:
 	.ascii	"__SA_IBIT__ 16\000"
@@ -5394,11 +5447,11 @@ main:
 	.ascii	"__ARM_FP16_FORMAT_IEEE\000"
 .LASF48:
 	.ascii	"__UINT16_TYPE__ short unsigned int\000"
-.LASF873:
+.LASF875:
 	.ascii	"RCC_PLLCFGR_PLLSRC_BIT 22\000"
-.LASF1035:
+.LASF1052:
 	.ascii	"gpio_write\000"
-.LASF1024:
+.LASF1041:
 	.ascii	"DIER\000"
 .LASF656:
 	.ascii	"_WCHAR_T_DEFINED_ \000"
@@ -5408,7 +5461,7 @@ main:
 	.ascii	"int +2\000"
 .LASF636:
 	.ascii	"INT8_C(x) __INT8_C(x)\000"
-.LASF974:
+.LASF991:
 	.ascii	"exit 42\000"
 .LASF63:
 	.ascii	"__UINT_FAST8_TYPE__ unsigned int\000"
@@ -5440,7 +5493,7 @@ main:
 	.ascii	"SCNx8 __SCN8(x)\000"
 .LASF208:
 	.ascii	"__FLT32_DENORM_MIN__ 1.4012984643248171e-45F32\000"
-.LASF1037:
+.LASF1054:
 	.ascii	"gpio_set_mode\000"
 .LASF125:
 	.ascii	"__UINT64_C(c) c ## ULL\000"
@@ -5452,19 +5505,19 @@ main:
 	.ascii	"__USFRACT_FBIT__ 8\000"
 .LASF191:
 	.ascii	"__LDBL_EPSILON__ 2.2204460492503131e-16L\000"
-.LASF910:
+.LASF923:
 	.ascii	"GPIOA ((struct gpio *) GPIOA_BASE_ADDR)\000"
 .LASF729:
 	.ascii	"PRIXLEAST16 __PRI16LEAST(X)\000"
 .LASF622:
 	.ascii	"INT_FAST64_MAX (__INT_FAST64_MAX__)\000"
-.LASF968:
+.LASF985:
 	.ascii	"USART_CR1_RE_BIT 2\000"
 .LASF373:
 	.ascii	"__GCC_ATOMIC_CHAR16_T_LOCK_FREE 2\000"
 .LASF789:
 	.ascii	"__PRI64FAST(x) __FAST64 __STRINGIFY(x)\000"
-.LASF897:
+.LASF910:
 	.ascii	"RCC_CFGR_SW_BIT 0\000"
 .LASF168:
 	.ascii	"__DBL_MAX_EXP__ 1024\000"
@@ -5510,7 +5563,7 @@ main:
 	.ascii	"PRIX32 __PRI32(X)\000"
 .LASF773:
 	.ascii	"SCNxLEAST32 __SCN32LEAST(x)\000"
-.LASF1039:
+.LASF1056:
 	.ascii	"tim4_start\000"
 .LASF711:
 	.ascii	"__SCN16LEAST(x) __LEAST16 __STRINGIFY(x)\000"
@@ -5518,7 +5571,7 @@ main:
 	.ascii	"__GNUC__ 12\000"
 .LASF692:
 	.ascii	"SCNiLEAST8 __SCN8LEAST(i)\000"
-.LASF943:
+.LASF960:
 	.ascii	"PWR ((struct pwr *) PWR_BASE_ADDR)\000"
 .LASF752:
 	.ascii	"PRId32 __PRI32(d)\000"
@@ -5542,7 +5595,7 @@ main:
 	.ascii	"__ULACCUM_MIN__ 0.0ULK\000"
 .LASF461:
 	.ascii	"_ATEXIT_DYNAMIC_ALLOC 1\000"
-.LASF981:
+.LASF998:
 	.ascii	"__uint32_t\000"
 .LASF188:
 	.ascii	"__LDBL_MAX__ 1.7976931348623157e+308L\000"
@@ -5552,7 +5605,7 @@ main:
 	.ascii	"__FLT_RADIX__ 2\000"
 .LASF454:
 	.ascii	"_INTTYPES_H \000"
-.LASF983:
+.LASF1000:
 	.ascii	"long long int\000"
 .LASF784:
 	.ascii	"SCNxFAST32 __SCN32FAST(x)\000"
@@ -5562,11 +5615,11 @@ main:
 	.ascii	"__LONG_WIDTH__ 32\000"
 .LASF602:
 	.ascii	"UINT32_MAX (__UINT32_MAX__)\000"
-.LASF1042:
+.LASF1059:
 	.ascii	"counter\000"
 .LASF648:
 	.ascii	"__wchar_t__ \000"
-.LASF945:
+.LASF962:
 	.ascii	"PWR_CR_VOS_BIT 14\000"
 .LASF195:
 	.ascii	"__LDBL_HAS_QUIET_NAN__ 1\000"
@@ -5578,7 +5631,7 @@ main:
 	.ascii	"WINT_MAX (__WINT_MAX__)\000"
 .LASF822:
 	.ascii	"SCNuFAST64 __SCN64FAST(u)\000"
-.LASF1010:
+.LASF1027:
 	.ascii	"SSCGR\000"
 .LASF137:
 	.ascii	"__UINT_FAST64_MAX__ 0xffffffffffffffffULL\000"
@@ -5592,13 +5645,13 @@ main:
 	.ascii	"__INTPTR_WIDTH__ 32\000"
 .LASF379:
 	.ascii	"__GCC_ATOMIC_LLONG_LOCK_FREE 1\000"
-.LASF956:
+.LASF973:
 	.ascii	"USART_SR_TXE_BIT 7\000"
-.LASF988:
+.LASF1005:
 	.ascii	"PLLCFGR\000"
 .LASF239:
 	.ascii	"__FLT32X_MIN__ 2.2250738585072014e-308F32x\000"
-.LASF938:
+.LASF955:
 	.ascii	"FLASH_ACR_LATENCY_BIT 0\000"
 .LASF218:
 	.ascii	"__FLT64_MAX_EXP__ 1024\000"
@@ -5606,13 +5659,13 @@ main:
 	.ascii	"__WCHAR_T \000"
 .LASF223:
 	.ascii	"__FLT64_MIN__ 2.2250738585072014e-308F64\000"
-.LASF919:
+.LASF936:
 	.ascii	"GPIO_AFRL_AFRL3_USART2_RX (0b0111)\000"
 .LASF553:
 	.ascii	"___int32_t_defined 1\000"
 .LASF83:
 	.ascii	"__INT_WIDTH__ 32\000"
-.LASF994:
+.LASF1011:
 	.ascii	"APB2RSTR\000"
 .LASF409:
 	.ascii	"__ARM_ARCH_PROFILE\000"
@@ -5662,9 +5715,9 @@ main:
 	.ascii	"__ARM_NEON_FP\000"
 .LASF280:
 	.ascii	"__LLFRACT_EPSILON__ 0x1P-63LLR\000"
-.LASF1006:
+.LASF1023:
 	.ascii	"APB2LPENR\000"
-.LASF952:
+.LASF969:
 	.ascii	"TIM_ENABLE (1 << TIM_CR1_CEN_BIT)\000"
 .LASF820:
 	.ascii	"SCNiFAST64 __SCN64FAST(i)\000"
@@ -5672,11 +5725,11 @@ main:
 	.ascii	"_ANSIDECL_H_ \000"
 .LASF683:
 	.ascii	"SCNu8 __SCN8(u)\000"
-.LASF949:
+.LASF966:
 	.ascii	"TIM4_BASE_ADDR (0x40000800U)\000"
 .LASF261:
 	.ascii	"__UFRACT_FBIT__ 16\000"
-.LASF962:
+.LASF979:
 	.ascii	"USART_CR1_OVER8_BIT 15\000"
 .LASF342:
 	.ascii	"__UDQ_FBIT__ 64\000"
@@ -5689,19 +5742,18 @@ main:
 	.ascii	"__FLOAT_TYPE float\000"
 .LASF185:
 	.ascii	"__LDBL_MAX_10_EXP__ 308\000"
-.LASF940:
-	.ascii	"FLASH_ACR_LATENCY(latency) ((latency & FLASH_ACR_LA"
-	.ascii	"TENCY_MASK) << FLASH_ACR_LATENCY_BIT)\000"
+.LASF933:
+	.ascii	"GPIO_AFRH_AFRH8_MCO_1 (0b0000)\000"
 .LASF175:
 	.ascii	"__DBL_DENORM_MIN__ ((double)4.9406564584124654e-324"
 	.ascii	"L)\000"
 .LASF607:
 	.ascii	"INT64_MAX (__INT64_MAX__)\000"
-.LASF985:
+.LASF1002:
 	.ascii	"unsigned int\000"
-.LASF862:
+.LASF864:
 	.ascii	"RCC_CR_HSERDY_BIT 17\000"
-.LASF924:
+.LASF941:
 	.ascii	"GPIO_PORT_OFFSET (0x400U)\000"
 .LASF459:
 	.ascii	"__NEWLIB_MINOR__ 3\000"
@@ -5715,7 +5767,7 @@ main:
 	.ascii	"PRIiFAST16 __PRI16FAST(i)\000"
 .LASF292:
 	.ascii	"__USACCUM_IBIT__ 8\000"
-.LASF934:
+.LASF951:
 	.ascii	"FLASH_ACR_DCEN_ENABLE (1 <<FLASH_ACR_DCEN_BIT)\000"
 .LASF612:
 	.ascii	"INT_FAST8_MIN (-__INT_FAST8_MAX__ - 1)\000"
@@ -5741,9 +5793,11 @@ main:
 	.ascii	"__INT_FAST8_WIDTH__ 32\000"
 .LASF526:
 	.ascii	"__INT16 \"h\"\000"
+.LASF897:
+	.ascii	"RCC_CFGR_MCO1PRE_BIT 24\000"
 .LASF402:
 	.ascii	"__ARM_FEATURE_LDREX\000"
-.LASF1038:
+.LASF1055:
 	.ascii	"usart2_start\000"
 .LASF336:
 	.ascii	"__UQQ_FBIT__ 8\000"
@@ -5775,27 +5829,29 @@ main:
 	.ascii	"__ARM_FEATURE_COPROC 15\000"
 .LASF483:
 	.ascii	"__OBSOLETE_MATH_DEFAULT 1\000"
-.LASF869:
+.LASF926:
+	.ascii	"GPIO_MODER_MODER8_MASK (0b11)\000"
+.LASF871:
 	.ascii	"RCC_CR_HSION_ON (1 << RCC_CR_HSION_BIT)\000"
 .LASF670:
 	.ascii	"__PRI8FAST(x) __FAST8 __STRINGIFY(x)\000"
 .LASF82:
 	.ascii	"__SHRT_WIDTH__ 16\000"
-.LASF885:
+.LASF888:
 	.ascii	"RCC_CFGR_PPRE_DIV_2 (0b100)\000"
 .LASF586:
 	.ascii	"INTPTR_MAX (__INTPTR_MAX__)\000"
 .LASF667:
 	.ascii	"__STRINGIFY(a) #a\000"
-.LASF941:
+.LASF958:
 	.ascii	"PWR_H_ \000"
 .LASF356:
 	.ascii	"__USA_FBIT__ 16\000"
-.LASF1005:
+.LASF1022:
 	.ascii	"APB1LPENR\000"
 .LASF479:
 	.ascii	"__IEEE_LITTLE_ENDIAN \000"
-.LASF922:
+.LASF939:
 	.ascii	"GPIO_AFRL_AFRL2_USART2_TX (0b0111)\000"
 .LASF232:
 	.ascii	"__FLT32X_MIN_EXP__ (-1021)\000"
@@ -5807,6 +5863,8 @@ main:
 	.ascii	"__ATFILE_VISIBLE 0\000"
 .LASF372:
 	.ascii	"__GCC_ATOMIC_CHAR_LOCK_FREE 2\000"
+.LASF925:
+	.ascii	"GPIO_MODER_MODER8_BIT 16\000"
 .LASF270:
 	.ascii	"__LFRACT_EPSILON__ 0x1P-31LR\000"
 .LASF808:
@@ -5823,6 +5881,9 @@ main:
 	.ascii	"PRIuLEAST32 __PRI32LEAST(u)\000"
 .LASF407:
 	.ascii	"__ARM_SIZEOF_MINIMAL_ENUM 1\000"
+.LASF877:
+	.ascii	"RCC_PLLCFGR_PLLSRC_HSI (0 << RCC_PLLCFGR_PLLSRC_BIT"
+	.ascii	")\000"
 .LASF498:
 	.ascii	"_POINTER_INT long\000"
 .LASF238:
@@ -5839,7 +5900,7 @@ main:
 	.ascii	"WCHAR_MIN (__WCHAR_MIN__)\000"
 .LASF594:
 	.ascii	"INT16_MIN (-__INT16_MAX__ - 1)\000"
-.LASF1029:
+.LASF1046:
 	.ascii	"CCR2\000"
 .LASF189:
 	.ascii	"__LDBL_NORM_MAX__ 1.7976931348623157e+308L\000"
@@ -5855,7 +5916,7 @@ main:
 	.ascii	"__SCN16FAST(x) __FAST16 __STRINGIFY(x)\000"
 .LASF536:
 	.ascii	"__LEAST64 \"ll\"\000"
-.LASF867:
+.LASF869:
 	.ascii	"RCC_CR_HSIRDY_READY (1 << RCC_CR_HSIRDY_BIT)\000"
 .LASF658:
 	.ascii	"_WCHAR_T_H \000"
@@ -5869,7 +5930,7 @@ main:
 	.ascii	"_HAVE_CC_INHIBIT_LOOP_TO_LIBCALL 1\000"
 .LASF420:
 	.ascii	"__ARM_ARCH_ISA_THUMB 2\000"
-.LASF900:
+.LASF913:
 	.ascii	"RCC_AHB1ENR_GPIOAEN_BIT 0\000"
 .LASF709:
 	.ascii	"__PRI16FAST(x) __FAST16 __STRINGIFY(x)\000"
@@ -5879,6 +5940,8 @@ main:
 	.ascii	"_FSEEK_OPTIMIZATION 1\000"
 .LASF87:
 	.ascii	"__WINT_WIDTH__ 32\000"
+.LASF862:
+	.ascii	"RCC_CR_CSS_BIT 19\000"
 .LASF514:
 	.ascii	"long\000"
 .LASF65:
@@ -5889,7 +5952,7 @@ main:
 	.ascii	"__UFRACT_IBIT__ 0\000"
 .LASF399:
 	.ascii	"__ARM_32BIT_STATE 1\000"
-.LASF914:
+.LASF929:
 	.ascii	"GPIO_MODER_MODER2_BIT 4\000"
 .LASF107:
 	.ascii	"__INT8_C(c) c\000"
@@ -5897,7 +5960,7 @@ main:
 	.ascii	"__LFRACT_IBIT__ 0\000"
 .LASF16:
 	.ascii	"__SIZEOF_INT__ 4\000"
-.LASF967:
+.LASF984:
 	.ascii	"USART_CR1_TE_ENABLE (1 << USART_CR1_TE_BIT)\000"
 .LASF166:
 	.ascii	"__DBL_MIN_EXP__ (-1021)\000"
@@ -5907,17 +5970,19 @@ main:
 	.ascii	"SCNuFAST16 __SCN16FAST(u)\000"
 .LASF801:
 	.ascii	"SCNx64 __SCN64(x)\000"
-.LASF929:
+.LASF946:
 	.ascii	"PINPORT(pin) (pin >> 8)\000"
 .LASF198:
 	.ascii	"__FLT32_DIG__ 6\000"
-.LASF904:
+.LASF895:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV4 (0b110)\000"
+.LASF917:
 	.ascii	"RCC_APB1ENR_USART2EN_BIT 17\000"
-.LASF889:
+.LASF902:
 	.ascii	"RCC_CFGR_PPRE1_MASK (0b111)\000"
 .LASF645:
 	.ascii	"UINTMAX_C(x) __UINTMAX_C(x)\000"
-.LASF912:
+.LASF928:
 	.ascii	"GPIO_MODER_MODER3_MASK (0b11)\000"
 .LASF623:
 	.ascii	"UINT_FAST64_MAX (__UINT_FAST64_MAX__)\000"
@@ -5933,20 +5998,22 @@ main:
 	.ascii	"__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1\000"
 .LASF733:
 	.ascii	"SCNuLEAST16 __SCN16LEAST(u)\000"
-.LASF993:
+.LASF1010:
 	.ascii	"APB1RSTR\000"
 .LASF298:
 	.ascii	"__ACCUM_MIN__ (-0X1P15K-0X1P15K)\000"
 .LASF393:
 	.ascii	"__ARM_FEATURE_CRYPTO\000"
-.LASF999:
+.LASF1016:
 	.ascii	"APB1ENR\000"
 .LASF741:
 	.ascii	"SCNdFAST16 __SCN16FAST(d)\000"
-.LASF872:
+.LASF892:
+	.ascii	"RCC_CFGR_MCO1_BIT 21\000"
+.LASF874:
 	.ascii	"RCC_PLLCFGR_PLLQ(q) ((q & RCC_PLLCFGR_PLLQ_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLQ_BIT)\000"
-.LASF957:
+.LASF974:
 	.ascii	"USART_SR_TXE_TRANSMITTED (1 << USART_SR_TXE_BIT)\000"
 .LASF787:
 	.ascii	"__PRI64LEAST(x) __LEAST64 __STRINGIFY(x)\000"
@@ -5966,18 +6033,18 @@ main:
 	.ascii	"__NEWLIB_PATCHLEVEL__ 0\000"
 .LASF26:
 	.ascii	"__ORDER_LITTLE_ENDIAN__ 1234\000"
-.LASF874:
+.LASF876:
 	.ascii	"RCC_PLLCFGR_PLLSRC_HSE (1 << RCC_PLLCFGR_PLLSRC_BIT"
 	.ascii	")\000"
 .LASF155:
 	.ascii	"__FLT_NORM_MAX__ 3.4028234663852886e+38F\000"
-.LASF984:
+.LASF1001:
 	.ascii	"long long unsigned int\000"
 .LASF611:
 	.ascii	"UINT_LEAST64_MAX (__UINT_LEAST64_MAX__)\000"
 .LASF150:
 	.ascii	"__FLT_MIN_10_EXP__ (-37)\000"
-.LASF895:
+.LASF908:
 	.ascii	"RCC_CFGR_SWS_MASK (0b11)\000"
 .LASF312:
 	.ascii	"__ULACCUM_IBIT__ 32\000"
@@ -6003,8 +6070,8 @@ main:
 	.ascii	"SCNdFAST32 __SCN32FAST(d)\000"
 .LASF339:
 	.ascii	"__UHQ_IBIT__ 0\000"
-.LASF911:
-	.ascii	"GPIO_MODER_MODER3_BIT 7\000"
+.LASF927:
+	.ascii	"GPIO_MODER_MODER3_BIT 6\000"
 .LASF60:
 	.ascii	"__INT_FAST16_TYPE__ int\000"
 .LASF574:
@@ -6015,20 +6082,20 @@ main:
 	.ascii	"__SACCUM_MIN__ (-0X1P7HK-0X1P7HK)\000"
 .LASF274:
 	.ascii	"__ULFRACT_MAX__ 0XFFFFFFFFP-32ULR\000"
-.LASF880:
+.LASF883:
 	.ascii	"RCC_PLLCFGR_PLLN(n) ((n & RCC_PLLCFGR_PLLN_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLN_BIT)\000"
 .LASF56:
 	.ascii	"__UINT_LEAST16_TYPE__ short unsigned int\000"
-.LASF944:
+.LASF961:
 	.ascii	"PWR_SCALE3 (0b11)\000"
 .LASF573:
 	.ascii	"_INTMAX_T_DECLARED \000"
-.LASF1027:
+.LASF1044:
 	.ascii	"CCER\000"
 .LASF40:
 	.ascii	"__CHAR16_TYPE__ short unsigned int\000"
-.LASF959:
+.LASF976:
 	.ascii	"USART_SR_TC_COMPLETED (1 << USART_SR_TC_BIT)\000"
 .LASF231:
 	.ascii	"__FLT32X_DIG__ 15\000"
@@ -6072,6 +6139,8 @@ main:
 	.ascii	"SIZE_MAX (__SIZE_MAX__)\000"
 .LASF333:
 	.ascii	"__DQ_IBIT__ 0\000"
+.LASF898:
+	.ascii	"RCC_CFGR_MCO1PRE_MASK (0b111)\000"
 .LASF450:
 	.ascii	"__ARM_BF16_FORMAT_ALTERNATIVE\000"
 .LASF45:
@@ -6084,19 +6153,19 @@ main:
 	.ascii	"__int20__ +2\000"
 .LASF654:
 	.ascii	"_WCHAR_T_ \000"
-.LASF1023:
+.LASF1040:
 	.ascii	"SMCR\000"
 .LASF828:
 	.ascii	"PRIoMAX __PRIMAX(o)\000"
 .LASF747:
 	.ascii	"__SCN32(x) __INT32 __STRINGIFY(x)\000"
-.LASF939:
+.LASF956:
 	.ascii	"FLASH_ACR_LATENCY_MASK (0b1111)\000"
-.LASF1013:
+.LASF1030:
 	.ascii	"GPIO_MODE_INPUT\000"
 .LASF743:
 	.ascii	"SCNoFAST16 __SCN16FAST(o)\000"
-.LASF1040:
+.LASF1057:
 	.ascii	"usart2_init\000"
 .LASF345:
 	.ascii	"__UTQ_IBIT__ 0\000"
@@ -6122,7 +6191,7 @@ main:
 	.ascii	"PRIi16 __PRI16(i)\000"
 .LASF390:
 	.ascii	"__ARM_FEATURE_DSP 1\000"
-.LASF965:
+.LASF982:
 	.ascii	"USART_CR1_UE_ENABLE (1 << USART_CR1_UE_BIT)\000"
 .LASF825:
 	.ascii	"__SCNMAX(x) __STRINGIFY(ll ##x)\000"
@@ -6150,15 +6219,15 @@ main:
 	.ascii	"__UINT_LEAST32_TYPE__ long unsigned int\000"
 .LASF405:
 	.ascii	"__ARM_FEATURE_NUMERIC_MAXMIN\000"
-.LASF923:
+.LASF940:
 	.ascii	"GPIO_BASE_ADDR (0x40020000U)\000"
 .LASF38:
 	.ascii	"__INTMAX_TYPE__ long long int\000"
 .LASF377:
 	.ascii	"__GCC_ATOMIC_INT_LOCK_FREE 2\000"
-.LASF971:
+.LASF988:
 	.ascii	"USART_BRR_MANTISSA_MASK (0b111111111111)\000"
-.LASF960:
+.LASF977:
 	.ascii	"USART_SR_RXNE_BIT 5\000"
 .LASF561:
 	.ascii	"_INT8_T_DECLARED \000"
@@ -6166,7 +6235,7 @@ main:
 	.ascii	"__ARM_ARCH_7EM__ 1\000"
 .LASF428:
 	.ascii	"__ARM_FEATURE_FP16_SCALAR_ARITHMETIC\000"
-.LASF996:
+.LASF1013:
 	.ascii	"AHB1ENR\000"
 .LASF295:
 	.ascii	"__USACCUM_EPSILON__ 0x1P-8UHK\000"
@@ -6206,11 +6275,11 @@ main:
 	.ascii	"__DBL_DIG__ 15\000"
 .LASF275:
 	.ascii	"__ULFRACT_EPSILON__ 0x1P-32ULR\000"
-.LASF991:
+.LASF1008:
 	.ascii	"AHB2RSTR\000"
 .LASF671:
 	.ascii	"__SCN8(x) __INT8 __STRINGIFY(x)\000"
-.LASF887:
+.LASF900:
 	.ascii	"RCC_CFGR_PPRE2_MASK (0b111)\000"
 .LASF23:
 	.ascii	"__SIZEOF_SIZE_T__ 4\000"
@@ -6226,38 +6295,38 @@ main:
 	.ascii	"_FVWRITE_IN_STREAMIO 1\000"
 .LASF183:
 	.ascii	"__LDBL_MIN_10_EXP__ (-307)\000"
-.LASF920:
+.LASF937:
 	.ascii	"GPIO_AFRL_AFRL2_BIT 8\000"
 .LASF190:
 	.ascii	"__LDBL_MIN__ 2.2250738585072014e-308L\000"
 .LASF445:
 	.ascii	"__ARM_FEATURE_CDE\000"
-.LASF1019:
+.LASF1036:
 	.ascii	"KEYR\000"
 .LASF509:
 	.ascii	"unsigned\000"
 .LASF381:
 	.ascii	"__GCC_DESTRUCTIVE_SIZE 64\000"
-.LASF977:
+.LASF994:
 	.ascii	"short int\000"
 .LASF835:
 	.ascii	"SCNuMAX __SCNMAX(u)\000"
-.LASF955:
+.LASF972:
 	.ascii	"USART2 ((struct usart *) USART2_BASE_ADDR)\000"
 .LASF121:
 	.ascii	"__UINT16_C(c) c\000"
-.LASF972:
+.LASF989:
 	.ascii	"USART_BRR_FRACTION_BIT 0\000"
 .LASF359:
 	.ascii	"__UDA_IBIT__ 32\000"
 .LASF534:
 	.ascii	"__LEAST16 \"h\"\000"
-.LASF882:
+.LASF885:
 	.ascii	"RCC_PLLCFGR_PLLM_MASK (0b111111)\000"
 .LASF365:
 	.ascii	"__NO_INLINE__ 1\000"
-.LASF958:
-	.ascii	"USART_SR_TC_BIT 6\000"
+.LASF889:
+	.ascii	"RCC_CFGR_MCO1_HSI (0b00)\000"
 .LASF710:
 	.ascii	"__SCN16(x) __INT16 __STRINGIFY(x)\000"
 .LASF606:
@@ -6268,22 +6337,24 @@ main:
 	.ascii	"_ATTRIBUTE(attrs) __attribute__ (attrs)\000"
 .LASF443:
 	.ascii	"__ARM_FEATURE_COPROC\000"
-.LASF1016:
+.LASF1033:
 	.ascii	"GPIO_MODE_ANALOG\000"
 .LASF177:
 	.ascii	"__DBL_HAS_INFINITY__ 1\000"
-.LASF950:
+.LASF967:
 	.ascii	"TIM4 ((struct timer *) TIM4_BASE_ADDR)\000"
 .LASF95:
 	.ascii	"__SIG_ATOMIC_MAX__ 0x7fffffff\000"
 .LASF608:
 	.ascii	"UINT64_MAX (__UINT64_MAX__)\000"
-.LASF901:
+.LASF914:
 	.ascii	"RCC_AHB1ENR_GPIOAEN_ENABLE (1 << RCC_AHB1ENR_GPIOAE"
 	.ascii	"N_BIT)\000"
+.LASF932:
+	.ascii	"GPIO_AFRH_AFRH8_MASK (0b1111)\000"
 .LASF471:
 	.ascii	"_RETARGETABLE_LOCKING 1\000"
-.LASF933:
+.LASF950:
 	.ascii	"FLASH_ACR_DCEN_BIT 10\000"
 .LASF453:
 	.ascii	"__USES_INITFINI__ 1\000"
@@ -6307,7 +6378,7 @@ main:
 	.ascii	"__INT16_MAX__ 0x7fff\000"
 .LASF478:
 	.ascii	"__SYS_CONFIG_H__ \000"
-.LASF881:
+.LASF884:
 	.ascii	"RCC_PLLCFGR_PLLM_BIT 0\000"
 .LASF8:
 	.ascii	"__VERSION__ \"12.3.1 20230626\"\000"
@@ -6343,7 +6414,7 @@ main:
 	.ascii	"PRIdMAX __PRIMAX(d)\000"
 .LASF388:
 	.ascii	"__SIZEOF_WINT_T__ 4\000"
-.LASF886:
+.LASF899:
 	.ascii	"RCC_CFGR_PPRE2_BIT 13\000"
 .LASF782:
 	.ascii	"SCNoFAST32 __SCN32FAST(o)\000"
@@ -6355,11 +6426,11 @@ main:
 	.ascii	"__LDBL_DECIMAL_DIG__ 17\000"
 .LASF701:
 	.ascii	"PRIXFAST8 __PRI8FAST(X)\000"
-.LASF1043:
+.LASF1060:
 	.ascii	"led_on\000"
 .LASF308:
 	.ascii	"__LACCUM_MIN__ (-0X1P31LK-0X1P31LK)\000"
-.LASF1045:
+.LASF1062:
 	.ascii	"src/main.c\000"
 .LASF126:
 	.ascii	"__INT_FAST8_MAX__ 0x7fffffff\000"
@@ -6397,13 +6468,13 @@ main:
 	.ascii	"__ULLFRACT_MIN__ 0.0ULLR\000"
 .LASF651:
 	.ascii	"_T_WCHAR_ \000"
-.LASF1032:
+.LASF1049:
 	.ascii	"BDTR\000"
 .LASF382:
 	.ascii	"__GCC_CONSTRUCTIVE_SIZE 64\000"
 .LASF664:
 	.ascii	"_BSD_WCHAR_T_\000"
-.LASF1011:
+.LASF1028:
 	.ascii	"PLLI2SCFGR\000"
 .LASF277:
 	.ascii	"__LLFRACT_IBIT__ 0\000"
@@ -6411,23 +6482,23 @@ main:
 	.ascii	"UINT16_C(x) __UINT16_C(x)\000"
 .LASF756:
 	.ascii	"PRIx32 __PRI32(x)\000"
-.LASF1041:
+.LASF1058:
 	.ascii	"tim4_init\000"
-.LASF987:
+.LASF1004:
 	.ascii	"uint32_t\000"
-.LASF878:
+.LASF881:
 	.ascii	"RCC_PLLCFGR_PLLN_BIT 6\000"
 .LASF689:
 	.ascii	"PRIxLEAST8 __PRI8LEAST(x)\000"
 .LASF506:
 	.ascii	"_SYS__INTSUP_H \000"
-.LASF1021:
+.LASF1038:
 	.ascii	"OPTCR\000"
 .LASF290:
 	.ascii	"__SACCUM_EPSILON__ 0x1P-7HK\000"
 .LASF415:
 	.ascii	"__GCC_ASM_FLAG_OUTPUTS__ 1\000"
-.LASF931:
+.LASF948:
 	.ascii	"FLASH_BASE_ADDR (0x40023C00U)\000"
 .LASF745:
 	.ascii	"SCNxFAST16 __SCN16FAST(x)\000"
@@ -6451,9 +6522,11 @@ main:
 	.ascii	"__ULACCUM_EPSILON__ 0x1P-32ULK\000"
 .LASF181:
 	.ascii	"__LDBL_DIG__ 15\000"
+.LASF894:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV5 (0b111)\000"
 .LASF89:
 	.ascii	"__SIZE_WIDTH__ 32\000"
-.LASF876:
+.LASF879:
 	.ascii	"RCC_PLLCFGR_PLLP_MASK (0b11)\000"
 .LASF480:
 	.ascii	"_SUPPORTS_ERREXCEPT \000"
@@ -6461,7 +6534,7 @@ main:
 	.ascii	"__FLT64_DIG__ 15\000"
 .LASF524:
 	.ascii	"_INT32_EQ_LONG \000"
-.LASF884:
+.LASF887:
 	.ascii	"RCC_CFGR_PPRE_DIV_NONE 0\000"
 .LASF77:
 	.ascii	"__WINT_MAX__ 0xffffffffU\000"
@@ -6473,13 +6546,13 @@ main:
 	.ascii	"__PRI16(x) __INT16 __STRINGIFY(x)\000"
 .LASF159:
 	.ascii	"__FLT_HAS_DENORM__ 1\000"
-.LASF928:
+.LASF945:
 	.ascii	"PINNUM(pin) (pin & 0b1111)\000"
 .LASF768:
 	.ascii	"PRIXLEAST32 __PRI32LEAST(X)\000"
 .LASF171:
 	.ascii	"__DBL_MAX__ ((double)1.7976931348623157e+308L)\000"
-.LASF978:
+.LASF995:
 	.ascii	"short unsigned int\000"
 .LASF276:
 	.ascii	"__LLFRACT_FBIT__ 63\000"
@@ -6487,7 +6560,7 @@ main:
 	.ascii	"__FLT32_HAS_INFINITY__ 1\000"
 .LASF416:
 	.ascii	"__thumb__ 1\000"
-.LASF970:
+.LASF987:
 	.ascii	"USART_BRR_MANTISSA_BIT 4\000"
 .LASF421:
 	.ascii	"__ARMEL__ 1\000"
@@ -6497,23 +6570,25 @@ main:
 	.ascii	"__HQ_FBIT__ 15\000"
 .LASF854:
 	.ascii	"__bool_true_false_are_defined 1\000"
-.LASF964:
+.LASF981:
 	.ascii	"USART_CR1_UE_BIT 13\000"
-.LASF925:
+.LASF942:
 	.ascii	"GPIO(port) ((struct gpio*)(uintptr_t)(GPIO_BASE_ADD"
 	.ascii	"R + (GPIO_PORT_OFFSET * port)))\000"
 .LASF798:
 	.ascii	"SCNi64 __SCN64(i)\000"
-.LASF866:
+.LASF868:
 	.ascii	"RCC_CR_HSIRDY_BIT 1\000"
 .LASF80:
 	.ascii	"__SIZE_MAX__ 0xffffffffU\000"
-.LASF1034:
+.LASF1051:
 	.ascii	"usart2_write\000"
 .LASF818:
 	.ascii	"PRIXFAST64 __PRI64FAST(X)\000"
-.LASF930:
+.LASF947:
 	.ascii	"FLASH_H_ \000"
+.LASF863:
+	.ascii	"RCC_CR_CSS_ON (1 << RCC_CR_CSS_BIT)\000"
 .LASF412:
 	.ascii	"__ARM_ARCH\000"
 .LASF590:
@@ -6530,7 +6605,7 @@ main:
 	.ascii	"SCNuFAST32 __SCN32FAST(u)\000"
 .LASF522:
 	.ascii	"long +4\000"
-.LASF990:
+.LASF1007:
 	.ascii	"AHB1RSTR\000"
 .LASF723:
 	.ascii	"SCNx16 __SCN16(x)\000"
@@ -6540,7 +6615,7 @@ main:
 	.ascii	"__SCN64LEAST(x) __LEAST64 __STRINGIFY(x)\000"
 .LASF340:
 	.ascii	"__USQ_FBIT__ 32\000"
-.LASF1046:
+.LASF1063:
 	.ascii	"/home/alex/code/own/stm32-falling-sand\000"
 .LASF796:
 	.ascii	"PRIX64 __PRI64(X)\000"
@@ -6578,7 +6653,7 @@ main:
 	.ascii	"__DBL_MIN_10_EXP__ (-307)\000"
 .LASF795:
 	.ascii	"PRIx64 __PRI64(x)\000"
-.LASF966:
+.LASF983:
 	.ascii	"USART_CR1_TE_BIT 3\000"
 .LASF512:
 	.ascii	"__int20\000"
@@ -6598,7 +6673,7 @@ main:
 	.ascii	"__ULFRACT_IBIT__ 0\000"
 .LASF857:
 	.ascii	"RCC ((struct rcc *) RCC_BASE_ADDR)\000"
-.LASF892:
+.LASF905:
 	.ascii	"RCC_CFGR_HPRE_MASK (0b1111)\000"
 .LASF72:
 	.ascii	"__INT_MAX__ 0x7fffffff\000"
@@ -6606,7 +6681,7 @@ main:
 	.ascii	"__INT_LEAST64_TYPE__ long long int\000"
 .LASF103:
 	.ascii	"__UINT16_MAX__ 0xffff\000"
-.LASF942:
+.LASF959:
 	.ascii	"PWR_BASE_ADDR (0x40007000U)\000"
 .LASF446:
 	.ascii	"__ARM_FEATURE_CDE_COPROC\000"
diff --git a/build/main.i b/build/main.i
index e46b82c..e7ac7fc 100644
--- a/build/main.i
+++ b/build/main.i
@@ -2029,6 +2029,11 @@ struct rcc {
 #define RCC_CR_PLLON_ON (1 << RCC_CR_PLLON_BIT)
 
 
+#define RCC_CR_CSS_BIT 19
+#define RCC_CR_CSS_ON (1 << RCC_CR_CSS_BIT)
+
+
+
 #define RCC_CR_HSERDY_BIT 17
 #define RCC_CR_HSERDY_READY (1 << RCC_CR_HSERDY_BIT)
 
@@ -2051,6 +2056,7 @@ struct rcc {
 
 #define RCC_PLLCFGR_PLLSRC_BIT 22
 #define RCC_PLLCFGR_PLLSRC_HSE (1 << RCC_PLLCFGR_PLLSRC_BIT)
+#define RCC_PLLCFGR_PLLSRC_HSI (0 << RCC_PLLCFGR_PLLSRC_BIT)
 
 #define RCC_PLLCFGR_PLLP_BIT 16
 #define RCC_PLLCFGR_PLLP_MASK (0b11)
@@ -2070,6 +2076,21 @@ struct rcc {
 #define RCC_CFGR_PPRE_DIV_2 (0b100)
 
 
+#define RCC_CFGR_MCO1_HSI (0b00)
+#define RCC_CFGR_MCO1_HSE (0b10)
+#define RCC_CFGR_MCO1_PLL (0b11)
+
+#define RCC_CFGR_MCO1_BIT 21
+#define RCC_CFGR_MCO1_MASK (0b11)
+
+#define RCC_CFGR_MCO1PRE_DIV5 (0b111)
+#define RCC_CFGR_MCO1PRE_DIV4 (0b110)
+#define RCC_CFGR_MCO1PRE_DIV2 (0b100)
+
+#define RCC_CFGR_MCO1PRE_BIT 24
+#define RCC_CFGR_MCO1PRE_MASK (0b111)
+
+
 #define RCC_CFGR_PPRE2_BIT 13
 #define RCC_CFGR_PPRE2_MASK (0b111)
 
@@ -2090,6 +2111,7 @@ struct rcc {
 #define RCC_CFGR_SWS_MASK (0b11)
 
 
+#define RCC_CFGR_SW_PLL (0b10)
 #define RCC_CFGR_SW_PLL (0b10)
 
 #define RCC_CFGR_SW_BIT 0
@@ -2135,13 +2157,21 @@ struct gpio {
 #define GPIOA ((struct gpio *) GPIOA_BASE_ADDR)
 
 
-#define GPIO_MODER_MODER3_BIT 7
+#define GPIO_MODER_AF_MODE (0b10)
+
+#define GPIO_MODER_MODER8_BIT 16
+#define GPIO_MODER_MODER8_MASK (0b11)
+
+#define GPIO_MODER_MODER3_BIT 6
 #define GPIO_MODER_MODER3_MASK (0b11)
-#define GPIO_MODER_MODER3_AF (0b10)
 
 #define GPIO_MODER_MODER2_BIT 4
 #define GPIO_MODER_MODER2_MASK (0b11)
-#define GPIO_MODER_MODER2_AF (0b10)
+
+
+#define GPIO_AFRH_AFRH8_BIT 0
+#define GPIO_AFRH_AFRH8_MASK (0b1111)
+#define GPIO_AFRH_AFRH8_MCO_1 (0b0000)
 
 
 #define GPIO_AFRL_AFRL3_BIT 12
@@ -2176,9 +2206,9 @@ typedef enum {
 
 void gpio_set_mode(uint16_t pin, GPIO_MODE mode);
 void gpio_write(uint16_t pin, 
-# 64 "src/gpio.h" 3 4
+# 72 "src/gpio.h" 3 4
                              _Bool 
-# 64 "src/gpio.h"
+# 72 "src/gpio.h"
                                   val);
 # 6 "src/main.c" 2
 # 1 "src/flash.h" 1
@@ -2350,9 +2380,14 @@ static void system_clock_init(void) {
   ((struct pwr *) (0x40007000U))->CR |= ((0b11) << 14);
 
 
+  ((struct rcc *) (0x40023800U))->CR &= ~(1 << 0);
+# 34 "src/main.c"
   ((struct rcc *) (0x40023800U))->CR |= (1 << 16);
 
 
+  ((struct rcc *) (0x40023800U))->CR |= (1 << 19);
+
+
 
   while (!(((struct rcc *) (0x40023800U))->CR & (1 << 17)));
 
@@ -2361,10 +2396,11 @@ static void system_clock_init(void) {
   ((struct rcc *) (0x40023800U))->CR &= ~(1 << 24);
 
 
+
   ((struct rcc *) (0x40023800U))->PLLCFGR |= (1 << 22);
 
 
-  ((struct rcc *) (0x40023800U))->PLLCFGR |= ((25 & (0b111111)) << 0) | ((196 & (0b111111111)) << 6) | ((2 & (0b11)) << 16) | ((4 & (0b1111)) << 24);
+  ((struct rcc *) (0x40023800U))->PLLCFGR |= ((25 & (0b111111)) << 0) | ((192 & (0b111111111)) << 6) | ((2 & (0b11)) << 16) | ((4 & (0b1111)) << 24);
 
 
   ((struct rcc *) (0x40023800U))->CFGR &= ~((0b1111) << 4);
@@ -2383,26 +2419,23 @@ static void system_clock_init(void) {
 
 
 
-  while (!(((struct rcc *) (0x40023800U))->CR & (1 << 17)));
+  while (!(((struct rcc *) (0x40023800U))->CR & (1 << 25)));
 
 
   ((struct flash *) (0x40023C00U))->ACR |= (1 <<10);
   ((struct flash *) (0x40023C00U))->ACR |= (1 <<9);
 
 
-  ((struct flash *) (0x40023C00U))->ACR &= ~((0b1111) << 0);
-  ((struct rcc *) (0x40023800U))->CFGR |= ((0x0111) << 0);
 
 
-  ((struct rcc *) (0x40023800U))->CFGR &= ~((0b11) << 0);
-  ((struct rcc *) (0x40023800U))->CFGR |= ((0b10) << 0);
+
+
+
+  ((struct rcc *) (0x40023800U))->CFGR |= (((0b10) & (0b11)) << 0);
 
 
 
   while (((((struct rcc *) (0x40023800U))->CFGR >> 2) & (0b11)) != (0b10));
-
-
-  ((struct rcc *) (0x40023800U))->CR &= ~(1 << 0);
 }
 
 int main(void) {
@@ -2419,20 +2452,20 @@ int main(void) {
 
   uint16_t counter = ((struct timer *) (0x40000800U))->CNT;
   
-# 90 "src/main.c" 3 4
+# 103 "src/main.c" 3 4
  _Bool 
-# 90 "src/main.c"
+# 103 "src/main.c"
       led_on = 
-# 90 "src/main.c" 3 4
+# 103 "src/main.c" 3 4
                ((_Bool)+0u)
-# 90 "src/main.c"
+# 103 "src/main.c"
                     ;
   while(1) {
  if ((((struct timer *) (0x40000800U))->CNT - counter) >= 250) {
   led_on = !led_on;
   gpio_write(led, led_on);
 
-  usart2_write("hello, world\n");
+  usart2_write("hello, world!\n");
 
   counter = ((struct timer *) (0x40000800U))->CNT;
  }
diff --git a/build/main.o b/build/main.o
index 3687611..5a29d55 100644
Binary files a/build/main.o and b/build/main.o differ
diff --git a/build/timer.S b/build/timer.S
index aae1189..faa42c6 100644
--- a/build/timer.S
+++ b/build/timer.S
@@ -56,7 +56,7 @@ tim4_init:
 	.loc 1 14 35
 	ldr	r3, .L2+4
 	.loc 1 14 41
-	movw	r2, #47999
+	movw	r2, #30463
 	str	r2, [r3, #40]
 	.loc 1 17 35
 	ldr	r3, .L2+4
@@ -136,10 +136,10 @@ tim4_start:
 	.byte	0x4
 	.4byte	.Ldebug_abbrev0
 	.uleb128 0x7
-	.4byte	.LASF960
+	.4byte	.LASF973
 	.byte	0x1d
-	.4byte	.LASF961
-	.4byte	.LASF962
+	.4byte	.LASF974
+	.4byte	.LASF975
 	.4byte	.LLRL0
 	.4byte	0
 	.4byte	.Ldebug_line0
@@ -147,17 +147,17 @@ tim4_start:
 	.uleb128 0x3
 	.byte	0x1
 	.byte	0x6
-	.4byte	.LASF908
+	.4byte	.LASF921
 	.uleb128 0x3
 	.byte	0x1
 	.byte	0x8
-	.4byte	.LASF909
+	.4byte	.LASF922
 	.uleb128 0x3
 	.byte	0x2
 	.byte	0x5
-	.4byte	.LASF910
+	.4byte	.LASF923
 	.uleb128 0x4
-	.4byte	.LASF913
+	.4byte	.LASF926
 	.byte	0x2
 	.byte	0x39
 	.byte	0x1c
@@ -165,13 +165,13 @@ tim4_start:
 	.uleb128 0x3
 	.byte	0x2
 	.byte	0x7
-	.4byte	.LASF911
+	.4byte	.LASF924
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x5
-	.4byte	.LASF912
+	.4byte	.LASF925
 	.uleb128 0x4
-	.4byte	.LASF914
+	.4byte	.LASF927
 	.byte	0x2
 	.byte	0x4f
 	.byte	0x1b
@@ -179,15 +179,15 @@ tim4_start:
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF915
+	.4byte	.LASF928
 	.uleb128 0x3
 	.byte	0x8
 	.byte	0x5
-	.4byte	.LASF916
+	.4byte	.LASF929
 	.uleb128 0x3
 	.byte	0x8
 	.byte	0x7
-	.4byte	.LASF917
+	.4byte	.LASF930
 	.uleb128 0x8
 	.byte	0x4
 	.byte	0x5
@@ -195,15 +195,15 @@ tim4_start:
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF918
+	.4byte	.LASF931
 	.uleb128 0x4
-	.4byte	.LASF919
+	.4byte	.LASF932
 	.byte	0x3
 	.byte	0x24
 	.byte	0x14
 	.4byte	0x3f
 	.uleb128 0x4
-	.4byte	.LASF920
+	.4byte	.LASF933
 	.byte	0x3
 	.byte	0x30
 	.byte	0x14
@@ -224,13 +224,13 @@ tim4_start:
 	.4byte	0xa0
 	.byte	0
 	.uleb128 0x1
-	.4byte	.LASF921
+	.4byte	.LASF934
 	.byte	0x4
 	.byte	0x8
 	.4byte	0xa0
 	.byte	0x4
 	.uleb128 0x1
-	.4byte	.LASF922
+	.4byte	.LASF935
 	.byte	0x4
 	.byte	0x9
 	.4byte	0xa0
@@ -242,115 +242,115 @@ tim4_start:
 	.4byte	0xa0
 	.byte	0xc
 	.uleb128 0x1
-	.4byte	.LASF923
+	.4byte	.LASF936
 	.byte	0x4
 	.byte	0xb
 	.4byte	0xa0
 	.byte	0x10
 	.uleb128 0x1
-	.4byte	.LASF924
+	.4byte	.LASF937
 	.byte	0x4
 	.byte	0xc
 	.4byte	0xa0
 	.byte	0x14
 	.uleb128 0x1
-	.4byte	.LASF925
+	.4byte	.LASF938
 	.byte	0x4
 	.byte	0xd
 	.4byte	0x212
 	.byte	0x18
 	.uleb128 0x1
-	.4byte	.LASF926
+	.4byte	.LASF939
 	.byte	0x4
 	.byte	0xe
 	.4byte	0xa0
 	.byte	0x20
 	.uleb128 0x1
-	.4byte	.LASF927
+	.4byte	.LASF940
 	.byte	0x4
 	.byte	0xf
 	.4byte	0xa0
 	.byte	0x24
 	.uleb128 0x1
-	.4byte	.LASF928
+	.4byte	.LASF941
 	.byte	0x4
 	.byte	0x10
 	.4byte	0x212
 	.byte	0x28
 	.uleb128 0x1
-	.4byte	.LASF929
+	.4byte	.LASF942
 	.byte	0x4
 	.byte	0x11
 	.4byte	0xa0
 	.byte	0x30
 	.uleb128 0x1
-	.4byte	.LASF930
+	.4byte	.LASF943
 	.byte	0x4
 	.byte	0x12
 	.4byte	0xa0
 	.byte	0x34
 	.uleb128 0x1
-	.4byte	.LASF931
+	.4byte	.LASF944
 	.byte	0x4
 	.byte	0x13
 	.4byte	0x212
 	.byte	0x38
 	.uleb128 0x1
-	.4byte	.LASF932
+	.4byte	.LASF945
 	.byte	0x4
 	.byte	0x14
 	.4byte	0xa0
 	.byte	0x40
 	.uleb128 0x1
-	.4byte	.LASF933
+	.4byte	.LASF946
 	.byte	0x4
 	.byte	0x15
 	.4byte	0xa0
 	.byte	0x44
 	.uleb128 0x1
-	.4byte	.LASF934
+	.4byte	.LASF947
 	.byte	0x4
 	.byte	0x16
 	.4byte	0x212
 	.byte	0x48
 	.uleb128 0x1
-	.4byte	.LASF935
+	.4byte	.LASF948
 	.byte	0x4
 	.byte	0x17
 	.4byte	0xa0
 	.byte	0x50
 	.uleb128 0x1
-	.4byte	.LASF936
+	.4byte	.LASF949
 	.byte	0x4
 	.byte	0x18
 	.4byte	0xa0
 	.byte	0x54
 	.uleb128 0x1
-	.4byte	.LASF937
+	.4byte	.LASF950
 	.byte	0x4
 	.byte	0x19
 	.4byte	0x212
 	.byte	0x58
 	.uleb128 0x1
-	.4byte	.LASF938
+	.4byte	.LASF951
 	.byte	0x4
 	.byte	0x1a
 	.4byte	0xa0
 	.byte	0x60
 	.uleb128 0x1
-	.4byte	.LASF939
+	.4byte	.LASF952
 	.byte	0x4
 	.byte	0x1b
 	.4byte	0xa0
 	.byte	0x64
 	.uleb128 0x1
-	.4byte	.LASF940
+	.4byte	.LASF953
 	.byte	0x4
 	.byte	0x1c
 	.4byte	0x212
 	.byte	0x68
 	.uleb128 0x1
-	.4byte	.LASF941
+	.4byte	.LASF954
 	.byte	0x4
 	.byte	0x1d
 	.4byte	0xa0
@@ -362,25 +362,25 @@ tim4_start:
 	.4byte	0xa0
 	.byte	0x74
 	.uleb128 0x1
-	.4byte	.LASF942
+	.4byte	.LASF955
 	.byte	0x4
 	.byte	0x1f
 	.4byte	0x212
 	.byte	0x78
 	.uleb128 0x1
-	.4byte	.LASF943
+	.4byte	.LASF956
 	.byte	0x4
 	.byte	0x20
 	.4byte	0xa0
 	.byte	0x80
 	.uleb128 0x1
-	.4byte	.LASF944
+	.4byte	.LASF957
 	.byte	0x4
 	.byte	0x21
 	.4byte	0xa0
 	.byte	0x84
 	.uleb128 0x1
-	.4byte	.LASF945
+	.4byte	.LASF958
 	.byte	0x4
 	.byte	0x22
 	.4byte	0xa0
@@ -396,7 +396,7 @@ tim4_start:
 	.uleb128 0x5
 	.4byte	0x202
 	.uleb128 0xc
-	.4byte	.LASF946
+	.4byte	.LASF959
 	.byte	0x50
 	.byte	0x5
 	.byte	0x6
@@ -415,13 +415,13 @@ tim4_start:
 	.4byte	0xa0
 	.byte	0x4
 	.uleb128 0x1
-	.4byte	.LASF947
+	.4byte	.LASF960
 	.byte	0x5
 	.byte	0x9
 	.4byte	0xa0
 	.byte	0x8
 	.uleb128 0x1
-	.4byte	.LASF948
+	.4byte	.LASF961
 	.byte	0x5
 	.byte	0xa
 	.4byte	0xa0
@@ -439,19 +439,19 @@ tim4_start:
 	.4byte	0xa0
 	.byte	0x14
 	.uleb128 0x1
-	.4byte	.LASF949
+	.4byte	.LASF962
 	.byte	0x5
 	.byte	0xd
 	.4byte	0xa0
 	.byte	0x18
 	.uleb128 0x1
-	.4byte	.LASF950
+	.4byte	.LASF963
 	.byte	0x5
 	.byte	0xe
 	.4byte	0xa0
 	.byte	0x1c
 	.uleb128 0x1
-	.4byte	.LASF951
+	.4byte	.LASF964
 	.byte	0x5
 	.byte	0xf
 	.4byte	0xa0
@@ -481,31 +481,31 @@ tim4_start:
 	.4byte	0xa0
 	.byte	0x30
 	.uleb128 0x1
-	.4byte	.LASF952
+	.4byte	.LASF965
 	.byte	0x5
 	.byte	0x14
 	.4byte	0xa0
 	.byte	0x34
 	.uleb128 0x1
-	.4byte	.LASF953
+	.4byte	.LASF966
 	.byte	0x5
 	.byte	0x15
 	.4byte	0xa0
 	.byte	0x38
 	.uleb128 0x1
-	.4byte	.LASF954
+	.4byte	.LASF967
 	.byte	0x5
 	.byte	0x16
 	.4byte	0xa0
 	.byte	0x3c
 	.uleb128 0x1
-	.4byte	.LASF955
+	.4byte	.LASF968
 	.byte	0x5
 	.byte	0x17
 	.4byte	0xa0
 	.byte	0x40
 	.uleb128 0x1
-	.4byte	.LASF956
+	.4byte	.LASF969
 	.byte	0x5
 	.byte	0x18
 	.4byte	0xa0
@@ -517,21 +517,21 @@ tim4_start:
 	.4byte	0xa0
 	.byte	0x48
 	.uleb128 0x1
-	.4byte	.LASF957
+	.4byte	.LASF970
 	.byte	0x5
 	.byte	0x1a
 	.4byte	0xa0
 	.byte	0x4c
 	.byte	0
 	.uleb128 0x6
-	.4byte	.LASF958
+	.4byte	.LASF971
 	.byte	0x14
 	.4byte	.LFB1
 	.4byte	.LFE1-.LFB1
 	.uleb128 0x1
 	.byte	0x9c
 	.uleb128 0x6
-	.4byte	.LASF959
+	.4byte	.LASF972
 	.byte	0x4
 	.4byte	.LFB0
 	.4byte	.LFE0-.LFB0
@@ -3501,7 +3501,7 @@ tim4_start:
 	.uleb128 0x135
 	.4byte	.LASF850
 	.byte	0
-	.section	.debug_macro,"G",%progbits,wm4.rcc.h.37.a17300cb822ec078eaa06c79bfd3d786,comdat
+	.section	.debug_macro,"G",%progbits,wm4.rcc.h.37.3f1c030e2fd0ae54c1d5f4fbfda7d54f,comdat
 .Ldebug_macro14:
 	.2byte	0x5
 	.byte	0
@@ -3530,64 +3530,64 @@ tim4_start:
 	.uleb128 0x33
 	.4byte	.LASF858
 	.byte	0x5
-	.uleb128 0x36
+	.uleb128 0x37
 	.4byte	.LASF859
 	.byte	0x5
-	.uleb128 0x37
+	.uleb128 0x38
 	.4byte	.LASF860
 	.byte	0x5
-	.uleb128 0x3a
+	.uleb128 0x3b
 	.4byte	.LASF861
 	.byte	0x5
-	.uleb128 0x3b
+	.uleb128 0x3c
 	.4byte	.LASF862
 	.byte	0x5
-	.uleb128 0x3e
+	.uleb128 0x3f
 	.4byte	.LASF863
 	.byte	0x5
-	.uleb128 0x3f
+	.uleb128 0x40
 	.4byte	.LASF864
 	.byte	0x5
-	.uleb128 0x42
+	.uleb128 0x43
 	.4byte	.LASF865
 	.byte	0x5
-	.uleb128 0x43
+	.uleb128 0x44
 	.4byte	.LASF866
 	.byte	0x5
-	.uleb128 0x44
+	.uleb128 0x47
 	.4byte	.LASF867
 	.byte	0x5
-	.uleb128 0x46
+	.uleb128 0x48
 	.4byte	.LASF868
 	.byte	0x5
-	.uleb128 0x47
+	.uleb128 0x49
 	.4byte	.LASF869
 	.byte	0x5
-	.uleb128 0x49
+	.uleb128 0x4b
 	.4byte	.LASF870
 	.byte	0x5
-	.uleb128 0x4a
+	.uleb128 0x4c
 	.4byte	.LASF871
 	.byte	0x5
-	.uleb128 0x4b
+	.uleb128 0x4d
 	.4byte	.LASF872
 	.byte	0x5
-	.uleb128 0x4d
+	.uleb128 0x4f
 	.4byte	.LASF873
 	.byte	0x5
-	.uleb128 0x4e
+	.uleb128 0x50
 	.4byte	.LASF874
 	.byte	0x5
-	.uleb128 0x4f
+	.uleb128 0x51
 	.4byte	.LASF875
 	.byte	0x5
-	.uleb128 0x51
+	.uleb128 0x53
 	.4byte	.LASF876
 	.byte	0x5
-	.uleb128 0x52
+	.uleb128 0x54
 	.4byte	.LASF877
 	.byte	0x5
-	.uleb128 0x53
+	.uleb128 0x55
 	.4byte	.LASF878
 	.byte	0x5
 	.uleb128 0x57
@@ -3596,71 +3596,113 @@ tim4_start:
 	.uleb128 0x58
 	.4byte	.LASF880
 	.byte	0x5
-	.uleb128 0x5b
+	.uleb128 0x59
 	.4byte	.LASF881
 	.byte	0x5
-	.uleb128 0x5c
+	.uleb128 0x5d
 	.4byte	.LASF882
 	.byte	0x5
-	.uleb128 0x5f
+	.uleb128 0x5e
 	.4byte	.LASF883
 	.byte	0x5
-	.uleb128 0x60
+	.uleb128 0x61
 	.4byte	.LASF884
 	.byte	0x5
-	.uleb128 0x63
+	.uleb128 0x62
 	.4byte	.LASF885
 	.byte	0x5
-	.uleb128 0x65
+	.uleb128 0x63
 	.4byte	.LASF886
 	.byte	0x5
-	.uleb128 0x66
+	.uleb128 0x65
 	.4byte	.LASF887
 	.byte	0x5
-	.uleb128 0x69
+	.uleb128 0x66
 	.4byte	.LASF888
 	.byte	0x5
-	.uleb128 0x6b
+	.uleb128 0x68
 	.4byte	.LASF889
 	.byte	0x5
-	.uleb128 0x6c
+	.uleb128 0x69
 	.4byte	.LASF890
 	.byte	0x5
-	.uleb128 0x6f
+	.uleb128 0x6a
 	.4byte	.LASF891
 	.byte	0x5
-	.uleb128 0x71
+	.uleb128 0x6c
 	.4byte	.LASF892
 	.byte	0x5
-	.uleb128 0x72
+	.uleb128 0x6d
 	.4byte	.LASF893
 	.byte	0x5
-	.uleb128 0x73
+	.uleb128 0x70
 	.4byte	.LASF894
 	.byte	0x5
-	.uleb128 0x77
+	.uleb128 0x71
 	.4byte	.LASF895
 	.byte	0x5
-	.uleb128 0x78
+	.uleb128 0x74
 	.4byte	.LASF896
 	.byte	0x5
-	.uleb128 0x7b
+	.uleb128 0x75
 	.4byte	.LASF897
 	.byte	0x5
-	.uleb128 0x7c
+	.uleb128 0x78
 	.4byte	.LASF898
 	.byte	0x5
-	.uleb128 0x7e
+	.uleb128 0x7a
 	.4byte	.LASF899
 	.byte	0x5
-	.uleb128 0x7f
+	.uleb128 0x7b
 	.4byte	.LASF900
 	.byte	0x5
-	.uleb128 0x81
+	.uleb128 0x7e
 	.4byte	.LASF901
 	.byte	0x5
-	.uleb128 0x82
+	.uleb128 0x80
 	.4byte	.LASF902
+	.byte	0x5
+	.uleb128 0x81
+	.4byte	.LASF903
+	.byte	0x5
+	.uleb128 0x84
+	.4byte	.LASF904
+	.byte	0x5
+	.uleb128 0x85
+	.4byte	.LASF904
+	.byte	0x5
+	.uleb128 0x87
+	.4byte	.LASF905
+	.byte	0x5
+	.uleb128 0x88
+	.4byte	.LASF906
+	.byte	0x5
+	.uleb128 0x89
+	.4byte	.LASF907
+	.byte	0x5
+	.uleb128 0x8d
+	.4byte	.LASF908
+	.byte	0x5
+	.uleb128 0x8e
+	.4byte	.LASF909
+	.byte	0x5
+	.uleb128 0x91
+	.4byte	.LASF910
+	.byte	0x5
+	.uleb128 0x92
+	.4byte	.LASF911
+	.byte	0x5
+	.uleb128 0x94
+	.4byte	.LASF912
+	.byte	0x5
+	.uleb128 0x95
+	.4byte	.LASF913
+	.byte	0x5
+	.uleb128 0x97
+	.4byte	.LASF914
+	.byte	0x5
+	.uleb128 0x98
+	.4byte	.LASF915
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4.timer.h.2.2e929ede818fb0960868f1b0a08a1cbf,comdat
 .Ldebug_macro15:
@@ -3668,19 +3710,19 @@ tim4_start:
 	.byte	0
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF903
+	.4byte	.LASF916
 	.byte	0x5
 	.uleb128 0x1d
-	.4byte	.LASF904
+	.4byte	.LASF917
 	.byte	0x5
 	.uleb128 0x1e
-	.4byte	.LASF905
+	.4byte	.LASF918
 	.byte	0x5
 	.uleb128 0x20
-	.4byte	.LASF906
+	.4byte	.LASF919
 	.byte	0x5
 	.uleb128 0x21
-	.4byte	.LASF907
+	.4byte	.LASF920
 	.byte	0
 	.section	.debug_line,"",%progbits
 .Ldebug_line0:
@@ -3695,7 +3737,7 @@ tim4_start:
 	.ascii	"__UHA_FBIT__ 8\000"
 .LASF815:
 	.ascii	"PRIiFAST64 __PRI64FAST(i)\000"
-.LASF909:
+.LASF922:
 	.ascii	"unsigned char\000"
 .LASF225:
 	.ascii	"__FLT64_DENORM_MIN__ 4.9406564584124654e-324F64\000"
@@ -3739,9 +3781,11 @@ tim4_start:
 	.ascii	"__ULACCUM_FBIT__ 32\000"
 .LASF75:
 	.ascii	"__WCHAR_MAX__ 0xffffffffU\000"
+.LASF891:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV2 (0b100)\000"
 .LASF514:
 	.ascii	"__int20__\000"
-.LASF901:
+.LASF914:
 	.ascii	"RCC_APB1ENR_TIM4_BIT 2\000"
 .LASF18:
 	.ascii	"__SIZEOF_LONG_LONG__ 8\000"
@@ -3767,7 +3811,7 @@ tim4_start:
 	.ascii	"__ORDER_PDP_ENDIAN__ 3412\000"
 .LASF34:
 	.ascii	"__SIZE_TYPE__ unsigned int\000"
-.LASF902:
+.LASF915:
 	.ascii	"RCC_APB1ENR_TIM4_ENABLE (1 << RCC_APB1ENR_TIM4_BIT)"
 	.ascii	"\000"
 .LASF621:
@@ -3838,7 +3882,7 @@ tim4_start:
 	.ascii	"__SCNPTR(x) __STRINGIFY(x)\000"
 .LASF202:
 	.ascii	"__FLT32_MAX_10_EXP__ 38\000"
-.LASF886:
+.LASF899:
 	.ascii	"RCC_CFGR_HPRE_BIT 4\000"
 .LASF683:
 	.ascii	"SCNo8 __SCN8(o)\000"
@@ -3854,12 +3898,12 @@ tim4_start:
 	.ascii	"__need_wchar_t\000"
 .LASF199:
 	.ascii	"__FLT32_MIN_EXP__ (-125)\000"
-.LASF960:
+.LASF973:
 	.ascii	"GNU C2X 12.3.1 20230626 -mcpu=cortex-m4 -mthumb -mf"
 	.ascii	"loat-abi=hard -mfpu=fpv4-sp-d16 -march=armv7e-m+fp "
 	.ascii	"-g3 -ggdb -O0 -std=c2x -ffunction-sections -fdata-s"
 	.ascii	"ections -fno-builtin -fno-common\000"
-.LASF859:
+.LASF861:
 	.ascii	"RCC_CR_HSEON_BIT 16\000"
 .LASF596:
 	.ascii	"INT16_MAX (__INT16_MAX__)\000"
@@ -3873,7 +3917,7 @@ tim4_start:
 	.ascii	"__int_fast32_t_defined 1\000"
 .LASF133:
 	.ascii	"__INT_FAST64_WIDTH__ 64\000"
-.LASF957:
+.LASF970:
 	.ascii	"DMAR\000"
 .LASF660:
 	.ascii	"___int_wchar_t_h \000"
@@ -3885,6 +3929,8 @@ tim4_start:
 	.ascii	"INT16_C(x) __INT16_C(x)\000"
 .LASF250:
 	.ascii	"__SFRACT_EPSILON__ 0x1P-7HR\000"
+.LASF888:
+	.ascii	"RCC_CFGR_MCO1_MASK (0b11)\000"
 .LASF113:
 	.ascii	"__INT32_C(c) c ## L\000"
 .LASF27:
@@ -3915,28 +3961,27 @@ tim4_start:
 	.ascii	"__PRI32LEAST(x) __LEAST32 __STRINGIFY(x)\000"
 .LASF88:
 	.ascii	"__PTRDIFF_WIDTH__ 32\000"
-.LASF894:
-	.ascii	"RCC_CFGR_SW(clock) ((clock & RCC_CFGR_SW_MASK) << R"
-	.ascii	"CC_CFGR_SW_BIT)\000"
+.LASF886:
+	.ascii	"RCC_CFGR_MCO1_PLL (0b11)\000"
 .LASF134:
 	.ascii	"__UINT_FAST8_MAX__ 0xffffffffU\000"
 .LASF761:
 	.ascii	"SCNo32 __SCN32(o)\000"
 .LASF541:
 	.ascii	"_NOTHROW \000"
-.LASF952:
+.LASF965:
 	.ascii	"CCR1\000"
-.LASF953:
+.LASF966:
 	.ascii	"CCR2\000"
-.LASF954:
+.LASF967:
 	.ascii	"CCR3\000"
-.LASF955:
+.LASF968:
 	.ascii	"CCR4\000"
 .LASF307:
 	.ascii	"__LACCUM_IBIT__ 32\000"
 .LASF593:
 	.ascii	"INT_LEAST8_MAX (__INT_LEAST8_MAX__)\000"
-.LASF888:
+.LASF901:
 	.ascii	"RCC_CFGR_SWS_PLL (0b10)\000"
 .LASF560:
 	.ascii	"__EXP\000"
@@ -3954,7 +3999,7 @@ tim4_start:
 	.ascii	"__INT64 \"ll\"\000"
 .LASF138:
 	.ascii	"__INTPTR_MAX__ 0x7fffffff\000"
-.LASF936:
+.LASF949:
 	.ascii	"AHB2LPENR\000"
 .LASF500:
 	.ascii	"__RAND_MAX\000"
@@ -3964,7 +4009,7 @@ tim4_start:
 	.ascii	"INT_LEAST64_MIN (-__INT_LEAST64_MAX__ - 1)\000"
 .LASF614:
 	.ascii	"INT_FAST8_MAX (__INT_FAST8_MAX__)\000"
-.LASF898:
+.LASF911:
 	.ascii	"RCC_APB1ENR_PWREN_CLOCK_ENABLE (1 << RCC_APB1ENR_PW"
 	.ascii	"REN_BIT)\000"
 .LASF487:
@@ -3992,12 +4037,12 @@ tim4_start:
 	.ascii	"__ACCUM_FBIT__ 15\000"
 .LASF792:
 	.ascii	"PRId64 __PRI64(d)\000"
-.LASF872:
+.LASF875:
 	.ascii	"RCC_PLLCFGR_PLLP(p) ((p & RCC_PLLCFGR_PLLP_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLP_BIT)\000"
 .LASF302:
 	.ascii	"__UACCUM_IBIT__ 16\000"
-.LASF912:
+.LASF925:
 	.ascii	"long int\000"
 .LASF720:
 	.ascii	"SCNd16 __SCN16(d)\000"
@@ -4015,7 +4060,7 @@ tim4_start:
 	.ascii	"__FLT32X_EPSILON__ 2.2204460492503131e-16F32x\000"
 .LASF557:
 	.ascii	"___int_least16_t_defined 1\000"
-.LASF878:
+.LASF881:
 	.ascii	"RCC_PLLCFGR_PLLM(m) ((m & RCC_PLLCFGR_PLLM_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLM_BIT)\000"
 .LASF468:
@@ -4030,7 +4075,7 @@ tim4_start:
 	.ascii	"__LLFRACT_MIN__ (-0.5LLR-0.5LLR)\000"
 .LASF93:
 	.ascii	"__UINTMAX_C(c) c ## ULL\000"
-.LASF865:
+.LASF867:
 	.ascii	"RCC_PLLCFGR_PLLQ_BIT 24\000"
 .LASF31:
 	.ascii	"__SIZEOF_POINTER__ 4\000"
@@ -4038,7 +4083,7 @@ tim4_start:
 	.ascii	"INT_FAST64_MIN (-__INT_FAST64_MAX__ - 1)\000"
 .LASF371:
 	.ascii	"__GCC_ATOMIC_BOOL_LOCK_FREE 2\000"
-.LASF893:
+.LASF906:
 	.ascii	"RCC_CFGR_SW_MASK (0b11)\000"
 .LASF432:
 	.ascii	"__ARM_NEON__\000"
@@ -4074,7 +4119,7 @@ tim4_start:
 	.ascii	"__SIZEOF_LONG__ 4\000"
 .LASF754:
 	.ascii	"PRIi32 __PRI32(i)\000"
-.LASF933:
+.LASF946:
 	.ascii	"APB2ENR\000"
 .LASF822:
 	.ascii	"SCNoFAST64 __SCN64FAST(o)\000"
@@ -4088,7 +4133,7 @@ tim4_start:
 	.ascii	"__FLT32X_MIN_EXP__ (-1021)\000"
 .LASF816:
 	.ascii	"PRIoFAST64 __PRI64FAST(o)\000"
-.LASF935:
+.LASF948:
 	.ascii	"AHB1LPENR\000"
 .LASF406:
 	.ascii	"__ARM_FEATURE_SIMD32 1\000"
@@ -4100,7 +4145,7 @@ tim4_start:
 	.ascii	"PRIoLEAST16 __PRI16LEAST(o)\000"
 .LASF459:
 	.ascii	"__NEWLIB__ 4\000"
-.LASF945:
+.LASF958:
 	.ascii	"DCKCFGR\000"
 .LASF721:
 	.ascii	"SCNi16 __SCN16(i)\000"
@@ -4110,7 +4155,7 @@ tim4_start:
 	.ascii	"__FLT_DECIMAL_DIG__ 9\000"
 .LASF563:
 	.ascii	"_UINT8_T_DECLARED \000"
-.LASF908:
+.LASF921:
 	.ascii	"signed char\000"
 .LASF806:
 	.ascii	"PRIuLEAST64 __PRI64LEAST(u)\000"
@@ -4132,7 +4177,7 @@ tim4_start:
 	.ascii	"__GNUC_PATCHLEVEL__ 1\000"
 .LASF374:
 	.ascii	"__GCC_ATOMIC_CHAR32_T_LOCK_FREE 2\000"
-.LASF866:
+.LASF868:
 	.ascii	"RCC_PLLCFGR_PLLQ_MASK (0b1111)\000"
 .LASF120:
 	.ascii	"__UINT_LEAST16_MAX__ 0xffff\000"
@@ -4142,25 +4187,25 @@ tim4_start:
 	.ascii	"_STDINT_H \000"
 .LASF219:
 	.ascii	"__FLT64_MAX_10_EXP__ 308\000"
-.LASF874:
+.LASF877:
 	.ascii	"RCC_PLLCFGR_PLLN_MASK (0b111111111)\000"
-.LASF961:
+.LASF974:
 	.ascii	"src/timer.c\000"
-.LASF928:
+.LASF941:
 	.ascii	"RESERVED1\000"
-.LASF931:
+.LASF944:
 	.ascii	"RESERVED2\000"
 .LASF3:
 	.ascii	"__STDC_UTF_32__ 1\000"
-.LASF937:
+.LASF950:
 	.ascii	"RESERVED4\000"
 .LASF241:
 	.ascii	"__FLT32X_DENORM_MIN__ 4.9406564584124654e-324F32x\000"
-.LASF942:
+.LASF955:
 	.ascii	"RESERVED6\000"
 .LASF152:
 	.ascii	"__FLT_MAX_10_EXP__ 38\000"
-.LASF883:
+.LASF896:
 	.ascii	"RCC_CFGR_PPRE1_BIT 10\000"
 .LASF259:
 	.ascii	"__FRACT_MAX__ 0X7FFFP-15R\000"
@@ -4174,9 +4219,9 @@ tim4_start:
 	.ascii	"_READ_WRITE_RETURN_TYPE int\000"
 .LASF772:
 	.ascii	"SCNoLEAST32 __SCN32LEAST(o)\000"
-.LASF891:
+.LASF904:
 	.ascii	"RCC_CFGR_SW_PLL (0b10)\000"
-.LASF906:
+.LASF919:
 	.ascii	"TIM_CR1_CEN_BIT 0\000"
 .LASF798:
 	.ascii	"SCNd64 __SCN64(d)\000"
@@ -4196,15 +4241,15 @@ tim4_start:
 	.ascii	"__int_fast64_t_defined 1\000"
 .LASF838:
 	.ascii	"__PRIPTR(x) __STRINGIFY(x)\000"
-.LASF919:
+.LASF932:
 	.ascii	"uint16_t\000"
 .LASF417:
 	.ascii	"__thumb2__ 1\000"
 .LASF321:
 	.ascii	"__ULLACCUM_FBIT__ 32\000"
-.LASF897:
+.LASF910:
 	.ascii	"RCC_APB1ENR_PWREN_BIT 28\000"
-.LASF900:
+.LASF913:
 	.ascii	"RCC_APB1ENR_USART2EN_ENABLE (1 << RCC_APB1ENR_USART"
 	.ascii	"2EN_BIT)\000"
 .LASF366:
@@ -4213,19 +4258,19 @@ tim4_start:
 	.ascii	"_SYS_FEATURES_H \000"
 .LASF813:
 	.ascii	"SCNxLEAST64 __SCN64LEAST(x)\000"
-.LASF934:
+.LASF947:
 	.ascii	"RESERVED3\000"
 .LASF22:
 	.ascii	"__SIZEOF_LONG_DOUBLE__ 8\000"
-.LASF940:
+.LASF953:
 	.ascii	"RESERVED5\000"
-.LASF949:
+.LASF962:
 	.ascii	"CCMR1\000"
-.LASF950:
+.LASF963:
 	.ascii	"CCMR2\000"
 .LASF36:
 	.ascii	"__WCHAR_TYPE__ unsigned int\000"
-.LASF903:
+.LASF916:
 	.ascii	"TIMER_H_ \000"
 .LASF470:
 	.ascii	"_MB_LEN_MAX 8\000"
@@ -4243,7 +4288,7 @@ tim4_start:
 	.ascii	"__need_wchar_t \000"
 .LASF66:
 	.ascii	"__UINT_FAST64_TYPE__ long long unsigned int\000"
-.LASF889:
+.LASF902:
 	.ascii	"RCC_CFGR_SWS_BIT 2\000"
 .LASF156:
 	.ascii	"__FLT_MIN__ 1.1754943508222875e-38F\000"
@@ -4269,9 +4314,9 @@ tim4_start:
 	.ascii	"__SCN64(x) __INT64 __STRINGIFY(x)\000"
 .LASF647:
 	.ascii	"_GCC_WRAP_STDINT_H \000"
-.LASF913:
+.LASF926:
 	.ascii	"__uint16_t\000"
-.LASF930:
+.LASF943:
 	.ascii	"AHB2ENR\000"
 .LASF805:
 	.ascii	"PRIoLEAST64 __PRI64LEAST(o)\000"
@@ -4285,7 +4330,7 @@ tim4_start:
 	.ascii	"__UINT8_MAX__ 0xff\000"
 .LASF575:
 	.ascii	"_UINTMAX_T_DECLARED \000"
-.LASF946:
+.LASF959:
 	.ascii	"timer\000"
 .LASF184:
 	.ascii	"__LDBL_MAX_EXP__ 1024\000"
@@ -4297,6 +4342,8 @@ tim4_start:
 	.ascii	"__int8_t_defined 1\000"
 .LASF176:
 	.ascii	"__DBL_HAS_DENORM__ 1\000"
+.LASF885:
+	.ascii	"RCC_CFGR_MCO1_HSE (0b10)\000"
 .LASF625:
 	.ascii	"INTMAX_MAX (__INTMAX_MAX__)\000"
 .LASF602:
@@ -4311,7 +4358,7 @@ tim4_start:
 	.ascii	"__FLT_DENORM_MIN__ 1.4012984643248171e-45F\000"
 .LASF534:
 	.ascii	"__LEAST8 \"hh\"\000"
-.LASF885:
+.LASF898:
 	.ascii	"RCC_CFGR_HPRE_DIV_NONE 0\000"
 .LASF540:
 	.ascii	"_END_STD_C \000"
@@ -4323,13 +4370,13 @@ tim4_start:
 	.ascii	"PRIiLEAST16 __PRI16LEAST(i)\000"
 .LASF303:
 	.ascii	"__UACCUM_MIN__ 0.0UK\000"
-.LASF870:
+.LASF873:
 	.ascii	"RCC_PLLCFGR_PLLP_BIT 16\000"
 .LASF157:
 	.ascii	"__FLT_EPSILON__ 1.1920928955078125e-7F\000"
 .LASF770:
 	.ascii	"SCNdLEAST32 __SCN32LEAST(d)\000"
-.LASF925:
+.LASF938:
 	.ascii	"RESERVED0\000"
 .LASF807:
 	.ascii	"PRIxLEAST64 __PRI64LEAST(x)\000"
@@ -4349,7 +4396,7 @@ tim4_start:
 	.ascii	"INT_LEAST32_MIN (-__INT_LEAST32_MAX__ - 1)\000"
 .LASF376:
 	.ascii	"__GCC_ATOMIC_SHORT_LOCK_FREE 2\000"
-.LASF863:
+.LASF865:
 	.ascii	"RCC_CR_HSION_BIT 0\000"
 .LASF779:
 	.ascii	"PRIxFAST32 __PRI32FAST(x)\000"
@@ -4367,7 +4414,7 @@ tim4_start:
 	.ascii	"__LACCUM_FBIT__ 31\000"
 .LASF689:
 	.ascii	"PRIuLEAST8 __PRI8LEAST(u)\000"
-.LASF941:
+.LASF954:
 	.ascii	"BDCR\000"
 .LASF211:
 	.ascii	"__FLT32_HAS_QUIET_NAN__ 1\000"
@@ -4401,7 +4448,7 @@ tim4_start:
 	.ascii	"__FP_FAST_FMAF 1\000"
 .LASF629:
 	.ascii	"SIG_ATOMIC_MIN (-__STDINT_EXP(INT_MAX) - 1)\000"
-.LASF860:
+.LASF862:
 	.ascii	"RCC_CR_HSEON_ON (1 << RCC_CR_HSEON_BIT)\000"
 .LASF565:
 	.ascii	"_INT16_T_DECLARED \000"
@@ -4425,11 +4472,11 @@ tim4_start:
 	.ascii	"PRIdLEAST64 __PRI64LEAST(d)\000"
 .LASF255:
 	.ascii	"__USFRACT_EPSILON__ 0x1P-8UHR\000"
-.LASF858:
+.LASF860:
 	.ascii	"RCC_CR_HSERDY_READY (1 << RCC_CR_HSERDY_BIT)\000"
 .LASF763:
 	.ascii	"SCNx32 __SCN32(x)\000"
-.LASF922:
+.LASF935:
 	.ascii	"CFGR\000"
 .LASF558:
 	.ascii	"___int_least32_t_defined 1\000"
@@ -4499,7 +4546,7 @@ tim4_start:
 	.ascii	"___int8_t_defined 1\000"
 .LASF248:
 	.ascii	"__SFRACT_MIN__ (-0.5HR-0.5HR)\000"
-.LASF915:
+.LASF928:
 	.ascii	"long unsigned int\000"
 .LASF349:
 	.ascii	"__SA_IBIT__ 16\000"
@@ -4515,9 +4562,9 @@ tim4_start:
 	.ascii	"__ARM_FP16_FORMAT_IEEE\000"
 .LASF48:
 	.ascii	"__UINT16_TYPE__ short unsigned int\000"
-.LASF868:
+.LASF870:
 	.ascii	"RCC_PLLCFGR_PLLSRC_BIT 22\000"
-.LASF948:
+.LASF961:
 	.ascii	"DIER\000"
 .LASF657:
 	.ascii	"_WCHAR_T_DEFINED_ \000"
@@ -4575,7 +4622,7 @@ tim4_start:
 	.ascii	"__GCC_ATOMIC_CHAR16_T_LOCK_FREE 2\000"
 .LASF790:
 	.ascii	"__PRI64FAST(x) __FAST64 __STRINGIFY(x)\000"
-.LASF892:
+.LASF905:
 	.ascii	"RCC_CFGR_SW_BIT 0\000"
 .LASF168:
 	.ascii	"__DBL_MAX_EXP__ 1024\000"
@@ -4621,11 +4668,11 @@ tim4_start:
 	.ascii	"PRIX32 __PRI32(X)\000"
 .LASF774:
 	.ascii	"SCNxLEAST32 __SCN32LEAST(x)\000"
-.LASF958:
+.LASF971:
 	.ascii	"tim4_start\000"
 .LASF704:
 	.ascii	"SCNiFAST8 __SCN8FAST(i)\000"
-.LASF921:
+.LASF934:
 	.ascii	"PLLCFGR\000"
 .LASF5:
 	.ascii	"__GNUC__ 12\000"
@@ -4653,7 +4700,7 @@ tim4_start:
 	.ascii	"__ULACCUM_MIN__ 0.0ULK\000"
 .LASF462:
 	.ascii	"_ATEXIT_DYNAMIC_ALLOC 1\000"
-.LASF914:
+.LASF927:
 	.ascii	"__uint32_t\000"
 .LASF188:
 	.ascii	"__LDBL_MAX__ 1.7976931348623157e+308L\000"
@@ -4663,7 +4710,7 @@ tim4_start:
 	.ascii	"__FLT_RADIX__ 2\000"
 .LASF455:
 	.ascii	"_INTTYPES_H \000"
-.LASF916:
+.LASF929:
 	.ascii	"long long int\000"
 .LASF401:
 	.ascii	"__ARM_FEATURE_CMSE\000"
@@ -4683,7 +4730,7 @@ tim4_start:
 	.ascii	"WINT_MAX (__WINT_MAX__)\000"
 .LASF823:
 	.ascii	"SCNuFAST64 __SCN64FAST(u)\000"
-.LASF943:
+.LASF956:
 	.ascii	"SSCGR\000"
 .LASF137:
 	.ascii	"__UINT_FAST64_MAX__ 0xffffffffffffffffULL\000"
@@ -4711,7 +4758,7 @@ tim4_start:
 	.ascii	"___int32_t_defined 1\000"
 .LASF83:
 	.ascii	"__INT_WIDTH__ 32\000"
-.LASF927:
+.LASF940:
 	.ascii	"APB2RSTR\000"
 .LASF409:
 	.ascii	"__ARM_ARCH_PROFILE\000"
@@ -4763,9 +4810,9 @@ tim4_start:
 	.ascii	"__ARM_NEON_FP\000"
 .LASF280:
 	.ascii	"__LLFRACT_EPSILON__ 0x1P-63LLR\000"
-.LASF939:
+.LASF952:
 	.ascii	"APB2LPENR\000"
-.LASF907:
+.LASF920:
 	.ascii	"TIM_ENABLE (1 << TIM_CR1_CEN_BIT)\000"
 .LASF821:
 	.ascii	"SCNiFAST64 __SCN64FAST(i)\000"
@@ -4773,7 +4820,7 @@ tim4_start:
 	.ascii	"_ANSIDECL_H_ \000"
 .LASF684:
 	.ascii	"SCNu8 __SCN8(u)\000"
-.LASF904:
+.LASF917:
 	.ascii	"TIM4_BASE_ADDR (0x40000800U)\000"
 .LASF261:
 	.ascii	"__UFRACT_FBIT__ 16\000"
@@ -4793,9 +4840,9 @@ tim4_start:
 	.ascii	"L)\000"
 .LASF608:
 	.ascii	"INT64_MAX (__INT64_MAX__)\000"
-.LASF918:
+.LASF931:
 	.ascii	"unsigned int\000"
-.LASF857:
+.LASF859:
 	.ascii	"RCC_CR_HSERDY_BIT 17\000"
 .LASF460:
 	.ascii	"__NEWLIB_MINOR__ 3\000"
@@ -4833,6 +4880,8 @@ tim4_start:
 	.ascii	"__INT_FAST8_WIDTH__ 32\000"
 .LASF2:
 	.ascii	"__STDC_UTF_16__ 1\000"
+.LASF892:
+	.ascii	"RCC_CFGR_MCO1PRE_BIT 24\000"
 .LASF402:
 	.ascii	"__ARM_FEATURE_LDREX\000"
 .LASF336:
@@ -4865,13 +4914,13 @@ tim4_start:
 	.ascii	"__ARM_FEATURE_COPROC 15\000"
 .LASF484:
 	.ascii	"__OBSOLETE_MATH_DEFAULT 1\000"
-.LASF864:
+.LASF866:
 	.ascii	"RCC_CR_HSION_ON (1 << RCC_CR_HSION_BIT)\000"
 .LASF671:
 	.ascii	"__PRI8FAST(x) __FAST8 __STRINGIFY(x)\000"
 .LASF82:
 	.ascii	"__SHRT_WIDTH__ 16\000"
-.LASF880:
+.LASF883:
 	.ascii	"RCC_CFGR_PPRE_DIV_2 (0b100)\000"
 .LASF473:
 	.ascii	"_UNBUF_STREAM_OPT 1\000"
@@ -4879,7 +4928,7 @@ tim4_start:
 	.ascii	"__STRINGIFY(a) #a\000"
 .LASF356:
 	.ascii	"__USA_FBIT__ 16\000"
-.LASF938:
+.LASF951:
 	.ascii	"APB1LPENR\000"
 .LASF480:
 	.ascii	"__IEEE_LITTLE_ENDIAN \000"
@@ -4909,6 +4958,9 @@ tim4_start:
 	.ascii	"PRIuLEAST32 __PRI32LEAST(u)\000"
 .LASF407:
 	.ascii	"__ARM_SIZEOF_MINIMAL_ENUM 1\000"
+.LASF872:
+	.ascii	"RCC_PLLCFGR_PLLSRC_HSI (0 << RCC_PLLCFGR_PLLSRC_BIT"
+	.ascii	")\000"
 .LASF499:
 	.ascii	"_POINTER_INT long\000"
 .LASF238:
@@ -4939,7 +4991,7 @@ tim4_start:
 	.ascii	"__SCN16FAST(x) __FAST16 __STRINGIFY(x)\000"
 .LASF537:
 	.ascii	"__LEAST64 \"ll\"\000"
-.LASF862:
+.LASF864:
 	.ascii	"RCC_CR_HSIRDY_READY (1 << RCC_CR_HSIRDY_BIT)\000"
 .LASF659:
 	.ascii	"_WCHAR_T_H \000"
@@ -4961,6 +5013,8 @@ tim4_start:
 	.ascii	"_FSEEK_OPTIMIZATION 1\000"
 .LASF87:
 	.ascii	"__WINT_WIDTH__ 32\000"
+.LASF857:
+	.ascii	"RCC_CR_CSS_BIT 19\000"
 .LASF515:
 	.ascii	"long\000"
 .LASF65:
@@ -4987,9 +5041,11 @@ tim4_start:
 	.ascii	"SCNx64 __SCN64(x)\000"
 .LASF198:
 	.ascii	"__FLT32_DIG__ 6\000"
-.LASF899:
+.LASF890:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV4 (0b110)\000"
+.LASF912:
 	.ascii	"RCC_APB1ENR_USART2EN_BIT 17\000"
-.LASF884:
+.LASF897:
 	.ascii	"RCC_CFGR_PPRE1_MASK (0b111)\000"
 .LASF646:
 	.ascii	"UINTMAX_C(x) __UINTMAX_C(x)\000"
@@ -5007,17 +5063,19 @@ tim4_start:
 	.ascii	"__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1\000"
 .LASF734:
 	.ascii	"SCNuLEAST16 __SCN16LEAST(u)\000"
-.LASF926:
+.LASF939:
 	.ascii	"APB1RSTR\000"
 .LASF298:
 	.ascii	"__ACCUM_MIN__ (-0X1P15K-0X1P15K)\000"
 .LASF393:
 	.ascii	"__ARM_FEATURE_CRYPTO\000"
-.LASF932:
+.LASF945:
 	.ascii	"APB1ENR\000"
 .LASF742:
 	.ascii	"SCNdFAST16 __SCN16FAST(d)\000"
-.LASF867:
+.LASF887:
+	.ascii	"RCC_CFGR_MCO1_BIT 21\000"
+.LASF869:
 	.ascii	"RCC_PLLCFGR_PLLQ(q) ((q & RCC_PLLCFGR_PLLQ_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLQ_BIT)\000"
 .LASF788:
@@ -5038,18 +5096,18 @@ tim4_start:
 	.ascii	"__NEWLIB_PATCHLEVEL__ 0\000"
 .LASF26:
 	.ascii	"__ORDER_LITTLE_ENDIAN__ 1234\000"
-.LASF869:
+.LASF871:
 	.ascii	"RCC_PLLCFGR_PLLSRC_HSE (1 << RCC_PLLCFGR_PLLSRC_BIT"
 	.ascii	")\000"
 .LASF155:
 	.ascii	"__FLT_NORM_MAX__ 3.4028234663852886e+38F\000"
-.LASF917:
+.LASF930:
 	.ascii	"long long unsigned int\000"
 .LASF612:
 	.ascii	"UINT_LEAST64_MAX (__UINT_LEAST64_MAX__)\000"
 .LASF150:
 	.ascii	"__FLT_MIN_10_EXP__ (-37)\000"
-.LASF890:
+.LASF903:
 	.ascii	"RCC_CFGR_SWS_MASK (0b11)\000"
 .LASF312:
 	.ascii	"__ULACCUM_IBIT__ 32\000"
@@ -5083,14 +5141,14 @@ tim4_start:
 	.ascii	"__SACCUM_MIN__ (-0X1P7HK-0X1P7HK)\000"
 .LASF274:
 	.ascii	"__ULFRACT_MAX__ 0XFFFFFFFFP-32ULR\000"
-.LASF875:
+.LASF878:
 	.ascii	"RCC_PLLCFGR_PLLN(n) ((n & RCC_PLLCFGR_PLLN_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLN_BIT)\000"
 .LASF56:
 	.ascii	"__UINT_LEAST16_TYPE__ short unsigned int\000"
 .LASF574:
 	.ascii	"_INTMAX_T_DECLARED \000"
-.LASF951:
+.LASF964:
 	.ascii	"CCER\000"
 .LASF40:
 	.ascii	"__CHAR16_TYPE__ short unsigned int\000"
@@ -5136,6 +5194,8 @@ tim4_start:
 	.ascii	"SIZE_MAX (__SIZE_MAX__)\000"
 .LASF333:
 	.ascii	"__DQ_IBIT__ 0\000"
+.LASF893:
+	.ascii	"RCC_CFGR_MCO1PRE_MASK (0b111)\000"
 .LASF450:
 	.ascii	"__ARM_BF16_FORMAT_ALTERNATIVE\000"
 .LASF45:
@@ -5146,7 +5206,7 @@ tim4_start:
 	.ascii	"__int20__ +2\000"
 .LASF655:
 	.ascii	"_WCHAR_T_ \000"
-.LASF947:
+.LASF960:
 	.ascii	"SMCR\000"
 .LASF829:
 	.ascii	"PRIoMAX __PRIMAX(o)\000"
@@ -5154,7 +5214,7 @@ tim4_start:
 	.ascii	"__SCN32(x) __INT32 __STRINGIFY(x)\000"
 .LASF744:
 	.ascii	"SCNoFAST16 __SCN16FAST(o)\000"
-.LASF895:
+.LASF908:
 	.ascii	"RCC_AHB1ENR_GPIOAEN_BIT 0\000"
 .LASF345:
 	.ascii	"__UTQ_IBIT__ 0\000"
@@ -5218,7 +5278,7 @@ tim4_start:
 	.ascii	"__ARM_ARCH_7EM__ 1\000"
 .LASF428:
 	.ascii	"__ARM_FEATURE_FP16_SCALAR_ARITHMETIC\000"
-.LASF929:
+.LASF942:
 	.ascii	"AHB1ENR\000"
 .LASF295:
 	.ascii	"__USACCUM_EPSILON__ 0x1P-8UHK\000"
@@ -5258,11 +5318,11 @@ tim4_start:
 	.ascii	"__DBL_DIG__ 15\000"
 .LASF275:
 	.ascii	"__ULFRACT_EPSILON__ 0x1P-32ULR\000"
-.LASF924:
+.LASF937:
 	.ascii	"AHB2RSTR\000"
 .LASF672:
 	.ascii	"__SCN8(x) __INT8 __STRINGIFY(x)\000"
-.LASF882:
+.LASF895:
 	.ascii	"RCC_CFGR_PPRE2_MASK (0b111)\000"
 .LASF23:
 	.ascii	"__SIZEOF_SIZE_T__ 4\000"
@@ -5288,7 +5348,7 @@ tim4_start:
 	.ascii	"unsigned\000"
 .LASF381:
 	.ascii	"__GCC_DESTRUCTIVE_SIZE 64\000"
-.LASF910:
+.LASF923:
 	.ascii	"short int\000"
 .LASF836:
 	.ascii	"SCNuMAX __SCNMAX(u)\000"
@@ -5298,10 +5358,12 @@ tim4_start:
 	.ascii	"__UDA_IBIT__ 32\000"
 .LASF535:
 	.ascii	"__LEAST16 \"h\"\000"
-.LASF877:
+.LASF880:
 	.ascii	"RCC_PLLCFGR_PLLM_MASK (0b111111)\000"
 .LASF587:
 	.ascii	"INTPTR_MAX (__INTPTR_MAX__)\000"
+.LASF884:
+	.ascii	"RCC_CFGR_MCO1_HSI (0b00)\000"
 .LASF711:
 	.ascii	"__SCN16(x) __INT16 __STRINGIFY(x)\000"
 .LASF607:
@@ -5314,13 +5376,13 @@ tim4_start:
 	.ascii	"__ARM_FEATURE_COPROC\000"
 .LASF177:
 	.ascii	"__DBL_HAS_INFINITY__ 1\000"
-.LASF905:
+.LASF918:
 	.ascii	"TIM4 ((struct timer *) TIM4_BASE_ADDR)\000"
 .LASF95:
 	.ascii	"__SIG_ATOMIC_MAX__ 0x7fffffff\000"
 .LASF609:
 	.ascii	"UINT64_MAX (__UINT64_MAX__)\000"
-.LASF896:
+.LASF909:
 	.ascii	"RCC_AHB1ENR_GPIOAEN_ENABLE (1 << RCC_AHB1ENR_GPIOAE"
 	.ascii	"N_BIT)\000"
 .LASF472:
@@ -5347,7 +5409,7 @@ tim4_start:
 	.ascii	"__INT16_MAX__ 0x7fff\000"
 .LASF479:
 	.ascii	"__SYS_CONFIG_H__ \000"
-.LASF876:
+.LASF879:
 	.ascii	"RCC_PLLCFGR_PLLM_BIT 0\000"
 .LASF8:
 	.ascii	"__VERSION__ \"12.3.1 20230626\"\000"
@@ -5383,7 +5445,7 @@ tim4_start:
 	.ascii	"PRIdMAX __PRIMAX(d)\000"
 .LASF388:
 	.ascii	"__SIZEOF_WINT_T__ 4\000"
-.LASF881:
+.LASF894:
 	.ascii	"RCC_CFGR_PPRE2_BIT 13\000"
 .LASF783:
 	.ascii	"SCNoFAST32 __SCN32FAST(o)\000"
@@ -5395,6 +5457,9 @@ tim4_start:
 	.ascii	"__LDBL_DECIMAL_DIG__ 17\000"
 .LASF702:
 	.ascii	"PRIXFAST8 __PRI8FAST(X)\000"
+.LASF907:
+	.ascii	"RCC_CFGR_SW(clock) ((clock & RCC_CFGR_SW_MASK) << R"
+	.ascii	"CC_CFGR_SW_BIT)\000"
 .LASF308:
 	.ascii	"__LACCUM_MIN__ (-0X1P31LK-0X1P31LK)\000"
 .LASF785:
@@ -5435,13 +5500,13 @@ tim4_start:
 	.ascii	"__ULLFRACT_MIN__ 0.0ULLR\000"
 .LASF652:
 	.ascii	"_T_WCHAR_ \000"
-.LASF956:
+.LASF969:
 	.ascii	"BDTR\000"
 .LASF382:
 	.ascii	"__GCC_CONSTRUCTIVE_SIZE 64\000"
 .LASF665:
 	.ascii	"_BSD_WCHAR_T_\000"
-.LASF944:
+.LASF957:
 	.ascii	"PLLI2SCFGR\000"
 .LASF277:
 	.ascii	"__LLFRACT_IBIT__ 0\000"
@@ -5449,11 +5514,11 @@ tim4_start:
 	.ascii	"UINT16_C(x) __UINT16_C(x)\000"
 .LASF757:
 	.ascii	"PRIx32 __PRI32(x)\000"
-.LASF959:
+.LASF972:
 	.ascii	"tim4_init\000"
-.LASF920:
+.LASF933:
 	.ascii	"uint32_t\000"
-.LASF873:
+.LASF876:
 	.ascii	"RCC_PLLCFGR_PLLN_BIT 6\000"
 .LASF690:
 	.ascii	"PRIxLEAST8 __PRI8LEAST(x)\000"
@@ -5485,9 +5550,11 @@ tim4_start:
 	.ascii	"__ULACCUM_EPSILON__ 0x1P-32ULK\000"
 .LASF181:
 	.ascii	"__LDBL_DIG__ 15\000"
+.LASF889:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV5 (0b111)\000"
 .LASF89:
 	.ascii	"__SIZE_WIDTH__ 32\000"
-.LASF871:
+.LASF874:
 	.ascii	"RCC_PLLCFGR_PLLP_MASK (0b11)\000"
 .LASF481:
 	.ascii	"_SUPPORTS_ERREXCEPT \000"
@@ -5495,7 +5562,7 @@ tim4_start:
 	.ascii	"__FLT64_DIG__ 15\000"
 .LASF525:
 	.ascii	"_INT32_EQ_LONG \000"
-.LASF879:
+.LASF882:
 	.ascii	"RCC_CFGR_PPRE_DIV_NONE 0\000"
 .LASF77:
 	.ascii	"__WINT_MAX__ 0xffffffffU\000"
@@ -5511,7 +5578,7 @@ tim4_start:
 	.ascii	"PRIXLEAST32 __PRI32LEAST(X)\000"
 .LASF171:
 	.ascii	"__DBL_MAX__ ((double)1.7976931348623157e+308L)\000"
-.LASF911:
+.LASF924:
 	.ascii	"short unsigned int\000"
 .LASF276:
 	.ascii	"__LLFRACT_FBIT__ 63\000"
@@ -5527,7 +5594,7 @@ tim4_start:
 	.ascii	"__HQ_FBIT__ 15\000"
 .LASF799:
 	.ascii	"SCNi64 __SCN64(i)\000"
-.LASF861:
+.LASF863:
 	.ascii	"RCC_CR_HSIRDY_BIT 1\000"
 .LASF80:
 	.ascii	"__SIZE_MAX__ 0xffffffffU\000"
@@ -5535,6 +5602,8 @@ tim4_start:
 	.ascii	"__FLT32X_HAS_INFINITY__ 1\000"
 .LASF819:
 	.ascii	"PRIXFAST64 __PRI64FAST(X)\000"
+.LASF858:
+	.ascii	"RCC_CR_CSS_ON (1 << RCC_CR_CSS_BIT)\000"
 .LASF412:
 	.ascii	"__ARM_ARCH\000"
 .LASF591:
@@ -5551,7 +5620,7 @@ tim4_start:
 	.ascii	"SCNuFAST32 __SCN32FAST(u)\000"
 .LASF523:
 	.ascii	"long +4\000"
-.LASF923:
+.LASF936:
 	.ascii	"AHB1RSTR\000"
 .LASF724:
 	.ascii	"SCNx16 __SCN16(x)\000"
@@ -5561,7 +5630,7 @@ tim4_start:
 	.ascii	"__SCN64LEAST(x) __LEAST64 __STRINGIFY(x)\000"
 .LASF340:
 	.ascii	"__USQ_FBIT__ 32\000"
-.LASF962:
+.LASF975:
 	.ascii	"/home/alex/code/own/stm32-falling-sand\000"
 .LASF797:
 	.ascii	"PRIX64 __PRI64(X)\000"
@@ -5613,7 +5682,7 @@ tim4_start:
 	.ascii	"__DBL_MANT_DIG__ 53\000"
 .LASF272:
 	.ascii	"__ULFRACT_IBIT__ 0\000"
-.LASF887:
+.LASF900:
 	.ascii	"RCC_CFGR_HPRE_MASK (0b1111)\000"
 .LASF72:
 	.ascii	"__INT_MAX__ 0x7fffffff\000"
diff --git a/build/timer.i b/build/timer.i
index 2ba9e1b..035f6ed 100644
--- a/build/timer.i
+++ b/build/timer.i
@@ -2014,6 +2014,11 @@ struct rcc {
 #define RCC_CR_PLLON_ON (1 << RCC_CR_PLLON_BIT)
 
 
+#define RCC_CR_CSS_BIT 19
+#define RCC_CR_CSS_ON (1 << RCC_CR_CSS_BIT)
+
+
+
 #define RCC_CR_HSERDY_BIT 17
 #define RCC_CR_HSERDY_READY (1 << RCC_CR_HSERDY_BIT)
 
@@ -2036,6 +2041,7 @@ struct rcc {
 
 #define RCC_PLLCFGR_PLLSRC_BIT 22
 #define RCC_PLLCFGR_PLLSRC_HSE (1 << RCC_PLLCFGR_PLLSRC_BIT)
+#define RCC_PLLCFGR_PLLSRC_HSI (0 << RCC_PLLCFGR_PLLSRC_BIT)
 
 #define RCC_PLLCFGR_PLLP_BIT 16
 #define RCC_PLLCFGR_PLLP_MASK (0b11)
@@ -2055,6 +2061,21 @@ struct rcc {
 #define RCC_CFGR_PPRE_DIV_2 (0b100)
 
 
+#define RCC_CFGR_MCO1_HSI (0b00)
+#define RCC_CFGR_MCO1_HSE (0b10)
+#define RCC_CFGR_MCO1_PLL (0b11)
+
+#define RCC_CFGR_MCO1_BIT 21
+#define RCC_CFGR_MCO1_MASK (0b11)
+
+#define RCC_CFGR_MCO1PRE_DIV5 (0b111)
+#define RCC_CFGR_MCO1PRE_DIV4 (0b110)
+#define RCC_CFGR_MCO1PRE_DIV2 (0b100)
+
+#define RCC_CFGR_MCO1PRE_BIT 24
+#define RCC_CFGR_MCO1PRE_MASK (0b111)
+
+
 #define RCC_CFGR_PPRE2_BIT 13
 #define RCC_CFGR_PPRE2_MASK (0b111)
 
@@ -2075,6 +2096,7 @@ struct rcc {
 #define RCC_CFGR_SWS_MASK (0b11)
 
 
+#define RCC_CFGR_SW_PLL (0b10)
 #define RCC_CFGR_SW_PLL (0b10)
 
 #define RCC_CFGR_SW_BIT 0
@@ -2145,7 +2167,7 @@ void tim4_init(void) {
 
 
 
-  ((struct timer *) (0x40000800U))->PSC = (uint16_t) 48000 - 1;
+  ((struct timer *) (0x40000800U))->PSC = (uint16_t) 96000 - 1;
 
 
   ((struct timer *) (0x40000800U))->ARR = (uint16_t) 0xFFFF;
diff --git a/build/timer.o b/build/timer.o
index ef13007..dbd3731 100644
Binary files a/build/timer.o and b/build/timer.o differ
diff --git a/build/usart.S b/build/usart.S
index e3a37e9..f0e688b 100644
--- a/build/usart.S
+++ b/build/usart.S
@@ -62,14 +62,14 @@ usart2_init:
 	ldr	r3, [r3]
 	ldr	r2, .L2+4
 	.loc 1 13 42
-	bic	r3, r3, #384
+	bic	r3, r3, #192
 	str	r3, [r2]
 	.loc 1 14 34
 	ldr	r3, .L2+4
 	ldr	r3, [r3]
 	ldr	r2, .L2+4
 	.loc 1 14 42
-	orr	r3, r3, #256
+	orr	r3, r3, #128
 	str	r3, [r2]
 	.loc 1 17 34
 	ldr	r3, .L2+4
@@ -99,71 +99,78 @@ usart2_init:
 	.loc 1 20 41
 	orr	r3, r3, #28672
 	str	r3, [r2, #32]
-	.loc 1 23 33
+	.loc 1 23 34
+	ldr	r3, .L2+4
+	ldr	r3, [r3]
+	ldr	r2, .L2+4
+	.loc 1 23 42
+	bic	r3, r3, #196608
+	str	r3, [r2]
+	.loc 1 24 34
+	ldr	r3, .L2+4
+	ldr	r3, [r3]
+	ldr	r2, .L2+4
+	.loc 1 24 42
+	orr	r3, r3, #131072
+	str	r3, [r2]
+	.loc 1 27 34
+	ldr	r3, .L2+4
+	ldr	r3, [r3, #36]
+	ldr	r2, .L2+4
+	.loc 1 27 41
+	bic	r3, r3, #15
+	str	r3, [r2, #36]
+	.loc 1 28 34
+	ldr	r3, .L2+4
+	ldr	r2, .L2+4
+	ldr	r3, [r3, #36]
+	.loc 1 28 41
+	str	r3, [r2, #36]
+	.loc 1 31 33
 	ldr	r3, .L2
 	ldr	r3, [r3, #64]
 	ldr	r2, .L2
-	.loc 1 23 43
+	.loc 1 31 43
 	orr	r3, r3, #131072
 	str	r3, [r2, #64]
-	.loc 1 26 35
+	.loc 1 34 35
 	ldr	r3, .L2+8
-	.loc 1 26 41
+	.loc 1 34 41
 	movs	r2, #0
 	str	r2, [r3, #12]
-	.loc 1 27 35
+	.loc 1 35 35
 	ldr	r3, .L2+8
-	.loc 1 27 41
+	.loc 1 35 41
 	movs	r2, #0
 	str	r2, [r3, #16]
-	.loc 1 28 35
+	.loc 1 36 35
 	ldr	r3, .L2+8
-	.loc 1 28 41
+	.loc 1 36 41
 	movs	r2, #0
 	str	r2, [r3, #20]
-	.loc 1 54 35
+	.loc 1 71 35
 	ldr	r3, .L2+8
 	ldr	r3, [r3, #8]
 	ldr	r2, .L2+8
-	.loc 1 54 41
-	bic	r3, r3, #65280
-	bic	r3, r3, #240
+	.loc 1 71 41
+	orr	r3, r3, #416
+	orr	r3, r3, #1
 	str	r3, [r2, #8]
-	.loc 1 55 35
-	ldr	r3, .L2+8
-	ldr	r3, [r3, #8]
-	ldr	r2, .L2+8
-	.loc 1 55 41
-	orr	r3, r3, #832
-	str	r3, [r2, #8]
-	.loc 1 58 35
-	ldr	r3, .L2+8
-	ldr	r3, [r3, #8]
-	ldr	r2, .L2+8
-	.loc 1 58 41
-	bic	r3, r3, #7
-	str	r3, [r2, #8]
-	.loc 1 59 35
-	ldr	r3, .L2+8
-	ldr	r2, .L2+8
-	ldr	r3, [r3, #8]
-	.loc 1 59 41
-	str	r3, [r2, #8]
-	.loc 1 62 35
+	.loc 1 74 35
 	ldr	r3, .L2+8
 	ldr	r3, [r3, #12]
 	ldr	r2, .L2+8
-	.loc 1 62 41
+	.loc 1 74 41
 	orr	r3, r3, #8
 	str	r3, [r2, #12]
-	.loc 1 63 35
+	.loc 1 75 35
 	ldr	r3, .L2+8
 	ldr	r3, [r3, #12]
 	ldr	r2, .L2+8
-	.loc 1 63 41
+	.loc 1 75 41
 	orr	r3, r3, #4
 	str	r3, [r2, #12]
-	.loc 1 64 1
+	.loc 1 76 1
 	nop
 	mov	sp, r7
 	.cfi_def_cfa_register 13
@@ -190,7 +197,7 @@ usart2_init:
 	.type	usart2_start, %function
 usart2_start:
 .LFB1:
-	.loc 1 66 25
+	.loc 1 78 25
 	.cfi_startproc
 	@ args = 0, pretend = 0, frame = 0
 	@ frame_needed = 1, uses_anonymous_args = 0
@@ -200,14 +207,14 @@ usart2_start:
 	.cfi_offset 7, -4
 	add	r7, sp, #0
 	.cfi_def_cfa_register 7
-	.loc 1 67 35
+	.loc 1 79 35
 	ldr	r3, .L5
 	ldr	r3, [r3, #12]
 	ldr	r2, .L5
-	.loc 1 67 41
+	.loc 1 79 41
 	orr	r3, r3, #8192
 	str	r3, [r2, #12]
-	.loc 1 68 1
+	.loc 1 80 1
 	nop
 	mov	sp, r7
 	.cfi_def_cfa_register 13
@@ -232,7 +239,7 @@ usart2_start:
 	.type	usart2_write_byte, %function
 usart2_write_byte:
 .LFB2:
-	.loc 1 70 35
+	.loc 1 82 35
 	.cfi_startproc
 	@ args = 0, pretend = 0, frame = 8
 	@ frame_needed = 1, uses_anonymous_args = 0
@@ -246,23 +253,23 @@ usart2_write_byte:
 	.cfi_def_cfa_register 7
 	mov	r3, r0
 	strb	r3, [r7, #7]
-	.loc 1 72 35
+	.loc 1 84 35
 	ldr	r2, .L9
-	.loc 1 72 40
+	.loc 1 84 40
 	ldrb	r3, [r7, #7]	@ zero_extendqisi2
 	str	r3, [r2, #4]
-	.loc 1 75 9
+	.loc 1 88 9
 	nop
 .L8:
-	.loc 1 75 43 discriminator 1
+	.loc 1 88 44 discriminator 1
 	ldr	r3, .L9
 	ldr	r3, [r3]
-	.loc 1 75 48 discriminator 1
-	and	r3, r3, #128
-	.loc 1 75 60 discriminator 1
+	.loc 1 88 49 discriminator 1
+	and	r3, r3, #64
+	.loc 1 88 10 discriminator 1
 	cmp	r3, #0
 	beq	.L8
-	.loc 1 77 1
+	.loc 1 89 1
 	nop
 	nop
 	adds	r7, r7, #12
@@ -290,7 +297,7 @@ usart2_write_byte:
 	.type	usart2_write, %function
 usart2_write:
 .LFB3:
-	.loc 1 79 30
+	.loc 1 91 30
 	.cfi_startproc
 	@ args = 0, pretend = 0, frame = 8
 	@ frame_needed = 1, uses_anonymous_args = 0
@@ -303,24 +310,24 @@ usart2_write:
 	add	r7, sp, #0
 	.cfi_def_cfa_register 7
 	str	r0, [r7, #4]
-	.loc 1 80 9
+	.loc 1 92 9
 	b	.L12
 .L13:
-	.loc 1 80 38 discriminator 2
+	.loc 1 92 38 discriminator 2
 	ldr	r3, [r7, #4]
 	adds	r2, r3, #1
 	str	r2, [r7, #4]
-	.loc 1 80 16 discriminator 2
+	.loc 1 92 16 discriminator 2
 	ldrb	r3, [r3]	@ zero_extendqisi2
 	mov	r0, r3
 	bl	usart2_write_byte
 .L12:
-	.loc 1 80 10 discriminator 1
+	.loc 1 92 10 discriminator 1
 	ldr	r3, [r7, #4]
 	ldrb	r3, [r3]	@ zero_extendqisi2
 	cmp	r3, #0
 	bne	.L13
-	.loc 1 81 1
+	.loc 1 93 1
 	nop
 	nop
 	adds	r7, r7, #8
@@ -347,10 +354,10 @@ usart2_write:
 	.byte	0x4
 	.4byte	.Ldebug_abbrev0
 	.uleb128 0x9
-	.4byte	.LASF1004
+	.4byte	.LASF1021
 	.byte	0x1d
-	.4byte	.LASF1005
-	.4byte	.LASF1006
+	.4byte	.LASF1022
+	.4byte	.LASF1023
 	.4byte	.LLRL0
 	.4byte	0
 	.4byte	.Ldebug_line0
@@ -358,9 +365,9 @@ usart2_write:
 	.uleb128 0x3
 	.byte	0x1
 	.byte	0x6
-	.4byte	.LASF951
+	.4byte	.LASF968
 	.uleb128 0x4
-	.4byte	.LASF956
+	.4byte	.LASF973
 	.byte	0x2
 	.byte	0x2b
 	.byte	0x17
@@ -368,21 +375,21 @@ usart2_write:
 	.uleb128 0x3
 	.byte	0x1
 	.byte	0x8
-	.4byte	.LASF952
+	.4byte	.LASF969
 	.uleb128 0x3
 	.byte	0x2
 	.byte	0x5
-	.4byte	.LASF953
+	.4byte	.LASF970
 	.uleb128 0x3
 	.byte	0x2
 	.byte	0x7
-	.4byte	.LASF954
+	.4byte	.LASF971
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x5
-	.4byte	.LASF955
+	.4byte	.LASF972
 	.uleb128 0x4
-	.4byte	.LASF957
+	.4byte	.LASF974
 	.byte	0x2
 	.byte	0x4f
 	.byte	0x1b
@@ -390,15 +397,15 @@ usart2_write:
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF958
+	.4byte	.LASF975
 	.uleb128 0x3
 	.byte	0x8
 	.byte	0x5
-	.4byte	.LASF959
+	.4byte	.LASF976
 	.uleb128 0x3
 	.byte	0x8
 	.byte	0x7
-	.4byte	.LASF960
+	.4byte	.LASF977
 	.uleb128 0xa
 	.byte	0x4
 	.byte	0x5
@@ -406,15 +413,15 @@ usart2_write:
 	.uleb128 0x3
 	.byte	0x4
 	.byte	0x7
-	.4byte	.LASF961
+	.4byte	.LASF978
 	.uleb128 0x4
-	.4byte	.LASF962
+	.4byte	.LASF979
 	.byte	0x3
 	.byte	0x18
 	.byte	0x13
 	.4byte	0x31
 	.uleb128 0x4
-	.4byte	.LASF963
+	.4byte	.LASF980
 	.byte	0x3
 	.byte	0x30
 	.byte	0x14
@@ -435,13 +442,13 @@ usart2_write:
 	.4byte	0xa0
 	.byte	0
 	.uleb128 0x1
-	.4byte	.LASF964
+	.4byte	.LASF981
 	.byte	0x4
 	.byte	0x8
 	.4byte	0xa0
 	.byte	0x4
 	.uleb128 0x1
-	.4byte	.LASF965
+	.4byte	.LASF982
 	.byte	0x4
 	.byte	0x9
 	.4byte	0xa0
@@ -453,115 +460,115 @@ usart2_write:
 	.4byte	0xa0
 	.byte	0xc
 	.uleb128 0x1
-	.4byte	.LASF966
+	.4byte	.LASF983
 	.byte	0x4
 	.byte	0xb
 	.4byte	0xa0
 	.byte	0x10
 	.uleb128 0x1
-	.4byte	.LASF967
+	.4byte	.LASF984
 	.byte	0x4
 	.byte	0xc
 	.4byte	0xa0
 	.byte	0x14
 	.uleb128 0x1
-	.4byte	.LASF968
+	.4byte	.LASF985
 	.byte	0x4
 	.byte	0xd
 	.4byte	0x212
 	.byte	0x18
 	.uleb128 0x1
-	.4byte	.LASF969
+	.4byte	.LASF986
 	.byte	0x4
 	.byte	0xe
 	.4byte	0xa0
 	.byte	0x20
 	.uleb128 0x1
-	.4byte	.LASF970
+	.4byte	.LASF987
 	.byte	0x4
 	.byte	0xf
 	.4byte	0xa0
 	.byte	0x24
 	.uleb128 0x1
-	.4byte	.LASF971
+	.4byte	.LASF988
 	.byte	0x4
 	.byte	0x10
 	.4byte	0x212
 	.byte	0x28
 	.uleb128 0x1
-	.4byte	.LASF972
+	.4byte	.LASF989
 	.byte	0x4
 	.byte	0x11
 	.4byte	0xa0
 	.byte	0x30
 	.uleb128 0x1
-	.4byte	.LASF973
+	.4byte	.LASF990
 	.byte	0x4
 	.byte	0x12
 	.4byte	0xa0
 	.byte	0x34
 	.uleb128 0x1
-	.4byte	.LASF974
+	.4byte	.LASF991
 	.byte	0x4
 	.byte	0x13
 	.4byte	0x212
 	.byte	0x38
 	.uleb128 0x1
-	.4byte	.LASF975
+	.4byte	.LASF992
 	.byte	0x4
 	.byte	0x14
 	.4byte	0xa0
 	.byte	0x40
 	.uleb128 0x1
-	.4byte	.LASF976
+	.4byte	.LASF993
 	.byte	0x4
 	.byte	0x15
 	.4byte	0xa0
 	.byte	0x44
 	.uleb128 0x1
-	.4byte	.LASF977
+	.4byte	.LASF994
 	.byte	0x4
 	.byte	0x16
 	.4byte	0x212
 	.byte	0x48
 	.uleb128 0x1
-	.4byte	.LASF978
+	.4byte	.LASF995
 	.byte	0x4
 	.byte	0x17
 	.4byte	0xa0
 	.byte	0x50
 	.uleb128 0x1
-	.4byte	.LASF979
+	.4byte	.LASF996
 	.byte	0x4
 	.byte	0x18
 	.4byte	0xa0
 	.byte	0x54
 	.uleb128 0x1
-	.4byte	.LASF980
+	.4byte	.LASF997
 	.byte	0x4
 	.byte	0x19
 	.4byte	0x212
 	.byte	0x58
 	.uleb128 0x1
-	.4byte	.LASF981
+	.4byte	.LASF998
 	.byte	0x4
 	.byte	0x1a
 	.4byte	0xa0
 	.byte	0x60
 	.uleb128 0x1
-	.4byte	.LASF982
+	.4byte	.LASF999
 	.byte	0x4
 	.byte	0x1b
 	.4byte	0xa0
 	.byte	0x64
 	.uleb128 0x1
-	.4byte	.LASF983
+	.4byte	.LASF1000
 	.byte	0x4
 	.byte	0x1c
 	.4byte	0x212
 	.byte	0x68
 	.uleb128 0x1
-	.4byte	.LASF984
+	.4byte	.LASF1001
 	.byte	0x4
 	.byte	0x1d
 	.4byte	0xa0
@@ -573,25 +580,25 @@ usart2_write:
 	.4byte	0xa0
 	.byte	0x74
 	.uleb128 0x1
-	.4byte	.LASF985
+	.4byte	.LASF1002
 	.byte	0x4
 	.byte	0x1f
 	.4byte	0x212
 	.byte	0x78
 	.uleb128 0x1
-	.4byte	.LASF986
+	.4byte	.LASF1003
 	.byte	0x4
 	.byte	0x20
 	.4byte	0xa0
 	.byte	0x80
 	.uleb128 0x1
-	.4byte	.LASF987
+	.4byte	.LASF1004
 	.byte	0x4
 	.byte	0x21
 	.4byte	0xa0
 	.byte	0x84
 	.uleb128 0x1
-	.4byte	.LASF988
+	.4byte	.LASF1005
 	.byte	0x4
 	.byte	0x22
 	.4byte	0xa0
@@ -607,31 +614,31 @@ usart2_write:
 	.uleb128 0x5
 	.4byte	0x202
 	.uleb128 0x6
-	.4byte	.LASF989
+	.4byte	.LASF1006
 	.byte	0x28
 	.byte	0x5
 	.byte	0x7
 	.4byte	0x29c
 	.uleb128 0x1
-	.4byte	.LASF990
+	.4byte	.LASF1007
 	.byte	0x5
 	.byte	0x8
 	.4byte	0xa0
 	.byte	0
 	.uleb128 0x1
-	.4byte	.LASF991
+	.4byte	.LASF1008
 	.byte	0x5
 	.byte	0x9
 	.4byte	0xa0
 	.byte	0x4
 	.uleb128 0x1
-	.4byte	.LASF992
+	.4byte	.LASF1009
 	.byte	0x5
 	.byte	0xa
 	.4byte	0xa0
 	.byte	0x8
 	.uleb128 0x1
-	.4byte	.LASF993
+	.4byte	.LASF1010
 	.byte	0x5
 	.byte	0xb
 	.4byte	0xa0
@@ -649,32 +656,32 @@ usart2_write:
 	.4byte	0xa0
 	.byte	0x14
 	.uleb128 0x1
-	.4byte	.LASF994
+	.4byte	.LASF1011
 	.byte	0x5
 	.byte	0xe
 	.4byte	0xa0
 	.byte	0x18
 	.uleb128 0x1
-	.4byte	.LASF995
+	.4byte	.LASF1012
 	.byte	0x5
 	.byte	0xf
 	.4byte	0xa0
 	.byte	0x1c
 	.uleb128 0x1
-	.4byte	.LASF996
+	.4byte	.LASF1013
 	.byte	0x5
 	.byte	0x10
 	.4byte	0xa0
 	.byte	0x20
 	.uleb128 0x1
-	.4byte	.LASF997
+	.4byte	.LASF1014
 	.byte	0x5
 	.byte	0x11
 	.4byte	0xa0
 	.byte	0x24
 	.byte	0
 	.uleb128 0x6
-	.4byte	.LASF998
+	.4byte	.LASF1015
 	.byte	0x1c
 	.byte	0x6
 	.byte	0x6
@@ -716,16 +723,16 @@ usart2_write:
 	.4byte	0xa0
 	.byte	0x14
 	.uleb128 0x1
-	.4byte	.LASF999
+	.4byte	.LASF1016
 	.byte	0x6
 	.byte	0xd
 	.4byte	0xa0
 	.byte	0x18
 	.byte	0
 	.uleb128 0xe
-	.4byte	.LASF1000
+	.4byte	.LASF1017
 	.byte	0x1
-	.byte	0x4f
+	.byte	0x5b
 	.byte	0x6
 	.4byte	.LFB3
 	.4byte	.LFE3-.LFB3
@@ -734,7 +741,7 @@ usart2_write:
 	.4byte	0x320
 	.uleb128 0x7
 	.ascii	"buf\000"
-	.byte	0x4f
+	.byte	0x5b
 	.byte	0x19
 	.4byte	0x320
 	.uleb128 0x2
@@ -749,9 +756,9 @@ usart2_write:
 	.byte	0x8
 	.4byte	.LASF511
 	.uleb128 0x10
-	.4byte	.LASF1001
+	.4byte	.LASF1018
 	.byte	0x1
-	.byte	0x46
+	.byte	0x52
 	.byte	0x6
 	.4byte	.LFB2
 	.4byte	.LFE2-.LFB2
@@ -760,7 +767,7 @@ usart2_write:
 	.4byte	0x350
 	.uleb128 0x7
 	.ascii	"c\000"
-	.byte	0x46
+	.byte	0x52
 	.byte	0x20
 	.4byte	0x88
 	.uleb128 0x2
@@ -768,14 +775,14 @@ usart2_write:
 	.sleb128 -9
 	.byte	0
 	.uleb128 0x8
-	.4byte	.LASF1002
-	.byte	0x42
+	.4byte	.LASF1019
+	.byte	0x4e
 	.4byte	.LFB1
 	.4byte	.LFE1-.LFB1
 	.uleb128 0x1
 	.byte	0x9c
 	.uleb128 0x8
-	.4byte	.LASF1003
+	.4byte	.LASF1020
 	.byte	0x5
 	.4byte	.LFB0
 	.4byte	.LFE0-.LFB0
@@ -2577,7 +2584,7 @@ usart2_write:
 	.uleb128 0x5
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF903
+	.4byte	.LASF916
 	.file 18 "/nix/store/yr89i11mszv2az19r26l372zgaiivj1c-gcc-arm-embedded-12.3.rel1/lib/gcc/arm-none-eabi/12.3.1/include/stdbool.h"
 	.byte	0x3
 	.uleb128 0x4
@@ -3853,7 +3860,7 @@ usart2_write:
 	.uleb128 0x135
 	.4byte	.LASF850
 	.byte	0
-	.section	.debug_macro,"G",%progbits,wm4.rcc.h.37.a17300cb822ec078eaa06c79bfd3d786,comdat
+	.section	.debug_macro,"G",%progbits,wm4.rcc.h.37.3f1c030e2fd0ae54c1d5f4fbfda7d54f,comdat
 .Ldebug_macro14:
 	.2byte	0x5
 	.byte	0
@@ -3882,64 +3889,64 @@ usart2_write:
 	.uleb128 0x33
 	.4byte	.LASF858
 	.byte	0x5
-	.uleb128 0x36
+	.uleb128 0x37
 	.4byte	.LASF859
 	.byte	0x5
-	.uleb128 0x37
+	.uleb128 0x38
 	.4byte	.LASF860
 	.byte	0x5
-	.uleb128 0x3a
+	.uleb128 0x3b
 	.4byte	.LASF861
 	.byte	0x5
-	.uleb128 0x3b
+	.uleb128 0x3c
 	.4byte	.LASF862
 	.byte	0x5
-	.uleb128 0x3e
+	.uleb128 0x3f
 	.4byte	.LASF863
 	.byte	0x5
-	.uleb128 0x3f
+	.uleb128 0x40
 	.4byte	.LASF864
 	.byte	0x5
-	.uleb128 0x42
+	.uleb128 0x43
 	.4byte	.LASF865
 	.byte	0x5
-	.uleb128 0x43
+	.uleb128 0x44
 	.4byte	.LASF866
 	.byte	0x5
-	.uleb128 0x44
+	.uleb128 0x47
 	.4byte	.LASF867
 	.byte	0x5
-	.uleb128 0x46
+	.uleb128 0x48
 	.4byte	.LASF868
 	.byte	0x5
-	.uleb128 0x47
+	.uleb128 0x49
 	.4byte	.LASF869
 	.byte	0x5
-	.uleb128 0x49
+	.uleb128 0x4b
 	.4byte	.LASF870
 	.byte	0x5
-	.uleb128 0x4a
+	.uleb128 0x4c
 	.4byte	.LASF871
 	.byte	0x5
-	.uleb128 0x4b
+	.uleb128 0x4d
 	.4byte	.LASF872
 	.byte	0x5
-	.uleb128 0x4d
+	.uleb128 0x4f
 	.4byte	.LASF873
 	.byte	0x5
-	.uleb128 0x4e
+	.uleb128 0x50
 	.4byte	.LASF874
 	.byte	0x5
-	.uleb128 0x4f
+	.uleb128 0x51
 	.4byte	.LASF875
 	.byte	0x5
-	.uleb128 0x51
+	.uleb128 0x53
 	.4byte	.LASF876
 	.byte	0x5
-	.uleb128 0x52
+	.uleb128 0x54
 	.4byte	.LASF877
 	.byte	0x5
-	.uleb128 0x53
+	.uleb128 0x55
 	.4byte	.LASF878
 	.byte	0x5
 	.uleb128 0x57
@@ -3948,71 +3955,113 @@ usart2_write:
 	.uleb128 0x58
 	.4byte	.LASF880
 	.byte	0x5
-	.uleb128 0x5b
+	.uleb128 0x59
 	.4byte	.LASF881
 	.byte	0x5
-	.uleb128 0x5c
+	.uleb128 0x5d
 	.4byte	.LASF882
 	.byte	0x5
-	.uleb128 0x5f
+	.uleb128 0x5e
 	.4byte	.LASF883
 	.byte	0x5
-	.uleb128 0x60
+	.uleb128 0x61
 	.4byte	.LASF884
 	.byte	0x5
-	.uleb128 0x63
+	.uleb128 0x62
 	.4byte	.LASF885
 	.byte	0x5
-	.uleb128 0x65
+	.uleb128 0x63
 	.4byte	.LASF886
 	.byte	0x5
-	.uleb128 0x66
+	.uleb128 0x65
 	.4byte	.LASF887
 	.byte	0x5
-	.uleb128 0x69
+	.uleb128 0x66
 	.4byte	.LASF888
 	.byte	0x5
-	.uleb128 0x6b
+	.uleb128 0x68
 	.4byte	.LASF889
 	.byte	0x5
-	.uleb128 0x6c
+	.uleb128 0x69
 	.4byte	.LASF890
 	.byte	0x5
-	.uleb128 0x6f
+	.uleb128 0x6a
 	.4byte	.LASF891
 	.byte	0x5
-	.uleb128 0x71
+	.uleb128 0x6c
 	.4byte	.LASF892
 	.byte	0x5
-	.uleb128 0x72
+	.uleb128 0x6d
 	.4byte	.LASF893
 	.byte	0x5
-	.uleb128 0x73
+	.uleb128 0x70
 	.4byte	.LASF894
 	.byte	0x5
-	.uleb128 0x77
+	.uleb128 0x71
 	.4byte	.LASF895
 	.byte	0x5
-	.uleb128 0x78
+	.uleb128 0x74
 	.4byte	.LASF896
 	.byte	0x5
-	.uleb128 0x7b
+	.uleb128 0x75
 	.4byte	.LASF897
 	.byte	0x5
-	.uleb128 0x7c
+	.uleb128 0x78
 	.4byte	.LASF898
 	.byte	0x5
-	.uleb128 0x7e
+	.uleb128 0x7a
 	.4byte	.LASF899
 	.byte	0x5
-	.uleb128 0x7f
+	.uleb128 0x7b
 	.4byte	.LASF900
 	.byte	0x5
-	.uleb128 0x81
+	.uleb128 0x7e
 	.4byte	.LASF901
 	.byte	0x5
-	.uleb128 0x82
+	.uleb128 0x80
 	.4byte	.LASF902
+	.byte	0x5
+	.uleb128 0x81
+	.4byte	.LASF903
+	.byte	0x5
+	.uleb128 0x84
+	.4byte	.LASF904
+	.byte	0x5
+	.uleb128 0x85
+	.4byte	.LASF904
+	.byte	0x5
+	.uleb128 0x87
+	.4byte	.LASF905
+	.byte	0x5
+	.uleb128 0x88
+	.4byte	.LASF906
+	.byte	0x5
+	.uleb128 0x89
+	.4byte	.LASF907
+	.byte	0x5
+	.uleb128 0x8d
+	.4byte	.LASF908
+	.byte	0x5
+	.uleb128 0x8e
+	.4byte	.LASF909
+	.byte	0x5
+	.uleb128 0x91
+	.4byte	.LASF910
+	.byte	0x5
+	.uleb128 0x92
+	.4byte	.LASF911
+	.byte	0x5
+	.uleb128 0x94
+	.4byte	.LASF912
+	.byte	0x5
+	.uleb128 0x95
+	.4byte	.LASF913
+	.byte	0x5
+	.uleb128 0x97
+	.4byte	.LASF914
+	.byte	0x5
+	.uleb128 0x98
+	.4byte	.LASF915
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4.stdbool.h.29.eb124ecb79face0a1d832a352bec45e0,comdat
 .Ldebug_macro15:
@@ -4020,87 +4069,99 @@ usart2_write:
 	.byte	0
 	.byte	0x5
 	.uleb128 0x1d
-	.4byte	.LASF904
-	.byte	0x5
-	.uleb128 0x21
-	.4byte	.LASF905
-	.byte	0x5
-	.uleb128 0x23
-	.4byte	.LASF906
-	.byte	0x5
-	.uleb128 0x24
-	.4byte	.LASF907
-	.byte	0x5
-	.uleb128 0x32
-	.4byte	.LASF908
-	.byte	0
-	.section	.debug_macro,"G",%progbits,wm4.gpio.h.20.b87a0d07dd796043155f078de080ca14,comdat
-.Ldebug_macro16:
-	.2byte	0x5
-	.byte	0
-	.byte	0x5
-	.uleb128 0x14
-	.4byte	.LASF909
-	.byte	0x5
-	.uleb128 0x15
-	.4byte	.LASF910
-	.byte	0x5
-	.uleb128 0x18
-	.4byte	.LASF911
-	.byte	0x5
-	.uleb128 0x19
-	.4byte	.LASF912
-	.byte	0x5
-	.uleb128 0x1a
-	.4byte	.LASF913
-	.byte	0x5
-	.uleb128 0x1c
-	.4byte	.LASF914
-	.byte	0x5
-	.uleb128 0x1d
-	.4byte	.LASF915
-	.byte	0x5
-	.uleb128 0x1e
-	.4byte	.LASF916
-	.byte	0x5
-	.uleb128 0x21
 	.4byte	.LASF917
 	.byte	0x5
-	.uleb128 0x22
+	.uleb128 0x21
 	.4byte	.LASF918
 	.byte	0x5
 	.uleb128 0x23
 	.4byte	.LASF919
 	.byte	0x5
-	.uleb128 0x25
+	.uleb128 0x24
 	.4byte	.LASF920
 	.byte	0x5
-	.uleb128 0x26
+	.uleb128 0x32
 	.4byte	.LASF921
+	.byte	0
+	.section	.debug_macro,"G",%progbits,wm4.gpio.h.20.3f94558e20af8751ceb103a1b8564792,comdat
+.Ldebug_macro16:
+	.2byte	0x5
+	.byte	0
 	.byte	0x5
-	.uleb128 0x27
+	.uleb128 0x14
 	.4byte	.LASF922
 	.byte	0x5
-	.uleb128 0x2c
+	.uleb128 0x15
 	.4byte	.LASF923
 	.byte	0x5
-	.uleb128 0x2d
+	.uleb128 0x18
 	.4byte	.LASF924
 	.byte	0x5
-	.uleb128 0x2e
+	.uleb128 0x1a
 	.4byte	.LASF925
 	.byte	0x5
-	.uleb128 0x30
+	.uleb128 0x1b
 	.4byte	.LASF926
 	.byte	0x5
-	.uleb128 0x32
+	.uleb128 0x1d
 	.4byte	.LASF927
 	.byte	0x5
-	.uleb128 0x34
+	.uleb128 0x1e
 	.4byte	.LASF928
 	.byte	0x5
-	.uleb128 0x36
+	.uleb128 0x20
 	.4byte	.LASF929
+	.byte	0x5
+	.uleb128 0x21
+	.4byte	.LASF930
+	.byte	0x5
+	.uleb128 0x24
+	.4byte	.LASF931
+	.byte	0x5
+	.uleb128 0x25
+	.4byte	.LASF932
+	.byte	0x5
+	.uleb128 0x26
+	.4byte	.LASF933
+	.byte	0x5
+	.uleb128 0x29
+	.4byte	.LASF934
+	.byte	0x5
+	.uleb128 0x2a
+	.4byte	.LASF935
+	.byte	0x5
+	.uleb128 0x2b
+	.4byte	.LASF936
+	.byte	0x5
+	.uleb128 0x2d
+	.4byte	.LASF937
+	.byte	0x5
+	.uleb128 0x2e
+	.4byte	.LASF938
+	.byte	0x5
+	.uleb128 0x2f
+	.4byte	.LASF939
+	.byte	0x5
+	.uleb128 0x34
+	.4byte	.LASF940
+	.byte	0x5
+	.uleb128 0x35
+	.4byte	.LASF941
+	.byte	0x5
+	.uleb128 0x36
+	.4byte	.LASF942
+	.byte	0x5
+	.uleb128 0x38
+	.4byte	.LASF943
+	.byte	0x5
+	.uleb128 0x3a
+	.4byte	.LASF944
+	.byte	0x5
+	.uleb128 0x3c
+	.4byte	.LASF945
+	.byte	0x5
+	.uleb128 0x3e
+	.4byte	.LASF946
 	.byte	0
 	.section	.debug_macro,"G",%progbits,wm4.usart.h.2.c32df0bd7cfa17e6f790f44d3d6388d5,comdat
 .Ldebug_macro17:
@@ -4108,67 +4169,67 @@ usart2_write:
 	.byte	0
 	.byte	0x5
 	.uleb128 0x2
-	.4byte	.LASF930
-	.byte	0x5
-	.uleb128 0x10
-	.4byte	.LASF931
-	.byte	0x5
-	.uleb128 0x11
-	.4byte	.LASF932
-	.byte	0x5
-	.uleb128 0x15
-	.4byte	.LASF933
-	.byte	0x5
-	.uleb128 0x16
-	.4byte	.LASF934
-	.byte	0x5
-	.uleb128 0x19
-	.4byte	.LASF935
-	.byte	0x5
-	.uleb128 0x1a
-	.4byte	.LASF936
-	.byte	0x5
-	.uleb128 0x1e
-	.4byte	.LASF937
-	.byte	0x5
-	.uleb128 0x1f
-	.4byte	.LASF938
-	.byte	0x5
-	.uleb128 0x23
-	.4byte	.LASF939
-	.byte	0x5
-	.uleb128 0x24
-	.4byte	.LASF940
-	.byte	0x5
-	.uleb128 0x27
-	.4byte	.LASF941
-	.byte	0x5
-	.uleb128 0x28
-	.4byte	.LASF942
-	.byte	0x5
-	.uleb128 0x2b
-	.4byte	.LASF943
-	.byte	0x5
-	.uleb128 0x2c
-	.4byte	.LASF944
-	.byte	0x5
-	.uleb128 0x2f
-	.4byte	.LASF945
-	.byte	0x5
-	.uleb128 0x30
-	.4byte	.LASF946
-	.byte	0x5
-	.uleb128 0x33
 	.4byte	.LASF947
 	.byte	0x5
-	.uleb128 0x34
+	.uleb128 0x10
 	.4byte	.LASF948
 	.byte	0x5
-	.uleb128 0x36
+	.uleb128 0x11
 	.4byte	.LASF949
 	.byte	0x5
-	.uleb128 0x37
+	.uleb128 0x15
 	.4byte	.LASF950
+	.byte	0x5
+	.uleb128 0x16
+	.4byte	.LASF951
+	.byte	0x5
+	.uleb128 0x19
+	.4byte	.LASF952
+	.byte	0x5
+	.uleb128 0x1a
+	.4byte	.LASF953
+	.byte	0x5
+	.uleb128 0x1e
+	.4byte	.LASF954
+	.byte	0x5
+	.uleb128 0x1f
+	.4byte	.LASF955
+	.byte	0x5
+	.uleb128 0x23
+	.4byte	.LASF956
+	.byte	0x5
+	.uleb128 0x24
+	.4byte	.LASF957
+	.byte	0x5
+	.uleb128 0x27
+	.4byte	.LASF958
+	.byte	0x5
+	.uleb128 0x28
+	.4byte	.LASF959
+	.byte	0x5
+	.uleb128 0x2b
+	.4byte	.LASF960
+	.byte	0x5
+	.uleb128 0x2c
+	.4byte	.LASF961
+	.byte	0x5
+	.uleb128 0x2f
+	.4byte	.LASF962
+	.byte	0x5
+	.uleb128 0x30
+	.4byte	.LASF963
+	.byte	0x5
+	.uleb128 0x33
+	.4byte	.LASF964
+	.byte	0x5
+	.uleb128 0x34
+	.4byte	.LASF965
+	.byte	0x5
+	.uleb128 0x36
+	.4byte	.LASF966
+	.byte	0x5
+	.uleb128 0x37
+	.4byte	.LASF967
 	.byte	0
 	.section	.debug_line,"",%progbits
 .Ldebug_line0:
@@ -4183,7 +4244,7 @@ usart2_write:
 	.ascii	"__UHA_FBIT__ 8\000"
 .LASF815:
 	.ascii	"PRIiFAST64 __PRI64FAST(i)\000"
-.LASF952:
+.LASF969:
 	.ascii	"unsigned char\000"
 .LASF225:
 	.ascii	"__FLT64_DENORM_MIN__ 4.9406564584124654e-324F64\000"
@@ -4211,7 +4272,7 @@ usart2_write:
 	.ascii	"__PTRDIFF_MAX__ 0x7fffffff\000"
 .LASF542:
 	.ascii	"_LONG_DOUBLE long double\000"
-.LASF989:
+.LASF1006:
 	.ascii	"gpio\000"
 .LASF592:
 	.ascii	"INT_LEAST8_MIN (-__INT_LEAST8_MAX__ - 1)\000"
@@ -4231,11 +4292,13 @@ usart2_write:
 	.ascii	"__ULACCUM_FBIT__ 32\000"
 .LASF75:
 	.ascii	"__WCHAR_MAX__ 0xffffffffU\000"
+.LASF891:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV2 (0b100)\000"
 .LASF514:
 	.ascii	"__int20__\000"
-.LASF901:
+.LASF914:
 	.ascii	"RCC_APB1ENR_TIM4_BIT 2\000"
-.LASF950:
+.LASF967:
 	.ascii	"USART_BRR_FRACTION_MASK (0b111)\000"
 .LASF18:
 	.ascii	"__SIZEOF_LONG_LONG__ 8\000"
@@ -4253,7 +4316,7 @@ usart2_write:
 	.ascii	"__SFRACT_FBIT__ 7\000"
 .LASF94:
 	.ascii	"__INTMAX_WIDTH__ 64\000"
-.LASF930:
+.LASF947:
 	.ascii	"USART_H_ \000"
 .LASF448:
 	.ascii	"__ARM_FEATURE_BF16_SCALAR_ARITHMETIC\000"
@@ -4263,7 +4326,7 @@ usart2_write:
 	.ascii	"__ORDER_PDP_ENDIAN__ 3412\000"
 .LASF34:
 	.ascii	"__SIZE_TYPE__ unsigned int\000"
-.LASF902:
+.LASF915:
 	.ascii	"RCC_APB1ENR_TIM4_ENABLE (1 << RCC_APB1ENR_TIM4_BIT)"
 	.ascii	"\000"
 .LASF621:
@@ -4296,8 +4359,6 @@ usart2_write:
 	.ascii	"RCC_BASE_ADDR (0x40023800U)\000"
 .LASF526:
 	.ascii	"__INT8 \"hh\"\000"
-.LASF913:
-	.ascii	"GPIO_MODER_MODER3_AF (0b10)\000"
 .LASF47:
 	.ascii	"__UINT8_TYPE__ unsigned char\000"
 .LASF368:
@@ -4306,7 +4367,7 @@ usart2_write:
 	.ascii	"INT_LEAST16_MAX (__INT_LEAST16_MAX__)\000"
 .LASF704:
 	.ascii	"SCNiFAST8 __SCN8FAST(i)\000"
-.LASF909:
+.LASF922:
 	.ascii	"GPIOA_BASE_ADDR (0x40020000U)\000"
 .LASF791:
 	.ascii	"__SCN64FAST(x) __FAST64 __STRINGIFY(x)\000"
@@ -4334,7 +4395,7 @@ usart2_write:
 	.ascii	"__SCNPTR(x) __STRINGIFY(x)\000"
 .LASF202:
 	.ascii	"__FLT32_MAX_10_EXP__ 38\000"
-.LASF886:
+.LASF899:
 	.ascii	"RCC_CFGR_HPRE_BIT 4\000"
 .LASF683:
 	.ascii	"SCNo8 __SCN8(o)\000"
@@ -4350,14 +4411,16 @@ usart2_write:
 	.ascii	"__need_wchar_t\000"
 .LASF199:
 	.ascii	"__FLT32_MIN_EXP__ (-125)\000"
-.LASF1004:
+.LASF1021:
 	.ascii	"GNU C2X 12.3.1 20230626 -mcpu=cortex-m4 -mthumb -mf"
 	.ascii	"loat-abi=hard -mfpu=fpv4-sp-d16 -march=armv7e-m+fp "
 	.ascii	"-g3 -ggdb -O0 -std=c2x -ffunction-sections -fdata-s"
 	.ascii	"ections -fno-builtin -fno-common\000"
-.LASF917:
+.LASF931:
+	.ascii	"GPIO_AFRH_AFRH8_BIT 0\000"
+.LASF934:
 	.ascii	"GPIO_AFRL_AFRL3_BIT 12\000"
-.LASF859:
+.LASF861:
 	.ascii	"RCC_CR_HSEON_BIT 16\000"
 .LASF596:
 	.ascii	"INT16_MAX (__INT16_MAX__)\000"
@@ -4373,7 +4436,7 @@ usart2_write:
 	.ascii	"__int_fast32_t_defined 1\000"
 .LASF133:
 	.ascii	"__INT_FAST64_WIDTH__ 64\000"
-.LASF879:
+.LASF882:
 	.ascii	"RCC_CFGR_PPRE_DIV_NONE 0\000"
 .LASF660:
 	.ascii	"___int_wchar_t_h \000"
@@ -4387,6 +4450,8 @@ usart2_write:
 	.ascii	"INT16_C(x) __INT16_C(x)\000"
 .LASF250:
 	.ascii	"__SFRACT_EPSILON__ 0x1P-7HR\000"
+.LASF888:
+	.ascii	"RCC_CFGR_MCO1_MASK (0b11)\000"
 .LASF113:
 	.ascii	"__INT32_C(c) c ## L\000"
 .LASF27:
@@ -4417,12 +4482,11 @@ usart2_write:
 	.ascii	"__PRI32LEAST(x) __LEAST32 __STRINGIFY(x)\000"
 .LASF88:
 	.ascii	"__PTRDIFF_WIDTH__ 32\000"
-.LASF894:
-	.ascii	"RCC_CFGR_SW(clock) ((clock & RCC_CFGR_SW_MASK) << R"
-	.ascii	"CC_CFGR_SW_BIT)\000"
+.LASF886:
+	.ascii	"RCC_CFGR_MCO1_PLL (0b11)\000"
 .LASF134:
 	.ascii	"__UINT_FAST8_MAX__ 0xffffffffU\000"
-.LASF949:
+.LASF966:
 	.ascii	"USART_BRR_FRACTION_BIT 0\000"
 .LASF541:
 	.ascii	"_NOTHROW \000"
@@ -4430,9 +4494,9 @@ usart2_write:
 	.ascii	"INT32_MIN (-__INT32_MAX__ - 1)\000"
 .LASF307:
 	.ascii	"__LACCUM_IBIT__ 32\000"
-.LASF888:
+.LASF901:
 	.ascii	"RCC_CFGR_SWS_PLL (0b10)\000"
-.LASF956:
+.LASF973:
 	.ascii	"__uint8_t\000"
 .LASF81:
 	.ascii	"__SCHAR_WIDTH__ 8\000"
@@ -4448,7 +4512,7 @@ usart2_write:
 	.ascii	"__INT64 \"ll\"\000"
 .LASF138:
 	.ascii	"__INTPTR_MAX__ 0x7fffffff\000"
-.LASF979:
+.LASF996:
 	.ascii	"AHB2LPENR\000"
 .LASF500:
 	.ascii	"__RAND_MAX\000"
@@ -4456,7 +4520,7 @@ usart2_write:
 	.ascii	"__UINT_FAST16_MAX__ 0xffffffffU\000"
 .LASF610:
 	.ascii	"INT_LEAST64_MIN (-__INT_LEAST64_MAX__ - 1)\000"
-.LASF898:
+.LASF911:
 	.ascii	"RCC_APB1ENR_PWREN_CLOCK_ENABLE (1 << RCC_APB1ENR_PW"
 	.ascii	"REN_BIT)\000"
 .LASF487:
@@ -4486,12 +4550,12 @@ usart2_write:
 	.ascii	"__ACCUM_FBIT__ 15\000"
 .LASF792:
 	.ascii	"PRId64 __PRI64(d)\000"
-.LASF872:
+.LASF875:
 	.ascii	"RCC_PLLCFGR_PLLP(p) ((p & RCC_PLLCFGR_PLLP_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLP_BIT)\000"
 .LASF302:
 	.ascii	"__UACCUM_IBIT__ 16\000"
-.LASF955:
+.LASF972:
 	.ascii	"long int\000"
 .LASF720:
 	.ascii	"SCNd16 __SCN16(d)\000"
@@ -4509,7 +4573,7 @@ usart2_write:
 	.ascii	"__FLT32X_EPSILON__ 2.2204460492503131e-16F32x\000"
 .LASF557:
 	.ascii	"___int_least16_t_defined 1\000"
-.LASF878:
+.LASF881:
 	.ascii	"RCC_PLLCFGR_PLLM(m) ((m & RCC_PLLCFGR_PLLM_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLM_BIT)\000"
 .LASF59:
@@ -4522,7 +4586,7 @@ usart2_write:
 	.ascii	"PRIdFAST32 __PRI32FAST(d)\000"
 .LASF93:
 	.ascii	"__UINTMAX_C(c) c ## ULL\000"
-.LASF865:
+.LASF867:
 	.ascii	"RCC_PLLCFGR_PLLQ_BIT 24\000"
 .LASF31:
 	.ascii	"__SIZEOF_POINTER__ 4\000"
@@ -4530,10 +4594,8 @@ usart2_write:
 	.ascii	"INT_FAST64_MIN (-__INT_FAST64_MAX__ - 1)\000"
 .LASF371:
 	.ascii	"__GCC_ATOMIC_BOOL_LOCK_FREE 2\000"
-.LASF893:
+.LASF906:
 	.ascii	"RCC_CFGR_SW_MASK (0b11)\000"
-.LASF916:
-	.ascii	"GPIO_MODER_MODER2_AF (0b10)\000"
 .LASF432:
 	.ascii	"__ARM_NEON__\000"
 .LASF588:
@@ -4546,7 +4608,7 @@ usart2_write:
 	.ascii	"__UINTMAX_TYPE__ long long unsigned int\000"
 .LASF284:
 	.ascii	"__ULLFRACT_MAX__ 0XFFFFFFFFFFFFFFFFP-64ULLR\000"
-.LASF938:
+.LASF955:
 	.ascii	"USART_SR_RXNE_READY (1 <<USART_SR_RXNE_BIT)\000"
 .LASF33:
 	.ascii	"__GNUC_WIDE_EXECUTION_CHARSET_NAME \"UTF-32LE\"\000"
@@ -4556,7 +4618,7 @@ usart2_write:
 	.ascii	"__CHAR32_TYPE__ long unsigned int\000"
 .LASF429:
 	.ascii	"__ARM_FEATURE_FP16_VECTOR_ARITHMETIC\000"
-.LASF903:
+.LASF916:
 	.ascii	"GPIO_H_ \000"
 .LASF179:
 	.ascii	"__DBL_IS_IEC_60559__ 2\000"
@@ -4568,7 +4630,7 @@ usart2_write:
 	.ascii	"__SIZEOF_LONG__ 4\000"
 .LASF754:
 	.ascii	"PRIi32 __PRI32(i)\000"
-.LASF976:
+.LASF993:
 	.ascii	"APB2ENR\000"
 .LASF822:
 	.ascii	"SCNoFAST64 __SCN64FAST(o)\000"
@@ -4582,7 +4644,7 @@ usart2_write:
 	.ascii	"__FLT32X_MIN_EXP__ (-1021)\000"
 .LASF816:
 	.ascii	"PRIoFAST64 __PRI64FAST(o)\000"
-.LASF978:
+.LASF995:
 	.ascii	"AHB1LPENR\000"
 .LASF406:
 	.ascii	"__ARM_FEATURE_SIMD32 1\000"
@@ -4594,23 +4656,23 @@ usart2_write:
 	.ascii	"PRIoLEAST16 __PRI16LEAST(o)\000"
 .LASF459:
 	.ascii	"__NEWLIB__ 4\000"
-.LASF988:
+.LASF1005:
 	.ascii	"DCKCFGR\000"
 .LASF721:
 	.ascii	"SCNi16 __SCN16(i)\000"
 .LASF360:
 	.ascii	"__UTA_FBIT__ 64\000"
-.LASF998:
+.LASF1015:
 	.ascii	"usart\000"
 .LASF153:
 	.ascii	"__FLT_DECIMAL_DIG__ 9\000"
 .LASF563:
 	.ascii	"_UINT8_T_DECLARED \000"
-.LASF951:
+.LASF968:
 	.ascii	"signed char\000"
 .LASF806:
 	.ascii	"PRIuLEAST64 __PRI64LEAST(u)\000"
-.LASF962:
+.LASF979:
 	.ascii	"uint8_t\000"
 .LASF705:
 	.ascii	"SCNoFAST8 __SCN8FAST(o)\000"
@@ -4626,11 +4688,13 @@ usart2_write:
 	.ascii	"PRIxFAST8 __PRI8FAST(x)\000"
 .LASF320:
 	.ascii	"__LLACCUM_EPSILON__ 0x1P-31LLK\000"
+.LASF952:
+	.ascii	"USART_SR_TC_BIT 6\000"
 .LASF7:
 	.ascii	"__GNUC_PATCHLEVEL__ 1\000"
 .LASF374:
 	.ascii	"__GCC_ATOMIC_CHAR32_T_LOCK_FREE 2\000"
-.LASF866:
+.LASF868:
 	.ascii	"RCC_PLLCFGR_PLLQ_MASK (0b1111)\000"
 .LASF120:
 	.ascii	"__UINT_LEAST16_MAX__ 0xffff\000"
@@ -4642,37 +4706,37 @@ usart2_write:
 	.ascii	"__SACCUM_MAX__ 0X7FFFP-7HK\000"
 .LASF219:
 	.ascii	"__FLT64_MAX_10_EXP__ 308\000"
-.LASF921:
+.LASF938:
 	.ascii	"GPIO_AFRL_AFRL2_MASK (0b1111)\000"
-.LASF874:
+.LASF877:
 	.ascii	"RCC_PLLCFGR_PLLN_MASK (0b111111111)\000"
-.LASF968:
+.LASF985:
 	.ascii	"RESERVED0\000"
-.LASF971:
+.LASF988:
 	.ascii	"RESERVED1\000"
-.LASF974:
+.LASF991:
 	.ascii	"RESERVED2\000"
 .LASF3:
 	.ascii	"__STDC_UTF_32__ 1\000"
-.LASF980:
+.LASF997:
 	.ascii	"RESERVED4\000"
 .LASF241:
 	.ascii	"__FLT32X_DENORM_MIN__ 4.9406564584124654e-324F32x\000"
-.LASF985:
+.LASF1002:
 	.ascii	"RESERVED6\000"
 .LASF152:
 	.ascii	"__FLT_MAX_10_EXP__ 38\000"
 .LASF42:
 	.ascii	"__SIG_ATOMIC_TYPE__ int\000"
-.LASF883:
+.LASF896:
 	.ascii	"RCC_CFGR_PPRE1_BIT 10\000"
 .LASF259:
 	.ascii	"__FRACT_MAX__ 0X7FFFP-15R\000"
 .LASF729:
 	.ascii	"PRIxLEAST16 __PRI16LEAST(x)\000"
-.LASF1001:
+.LASF1018:
 	.ascii	"usart2_write_byte\000"
-.LASF1005:
+.LASF1022:
 	.ascii	"src/usart.c\000"
 .LASF130:
 	.ascii	"__INT_FAST32_MAX__ 0x7fffffff\000"
@@ -4682,7 +4746,7 @@ usart2_write:
 	.ascii	"_READ_WRITE_RETURN_TYPE int\000"
 .LASF772:
 	.ascii	"SCNoLEAST32 __SCN32LEAST(o)\000"
-.LASF891:
+.LASF904:
 	.ascii	"RCC_CFGR_SW_PLL (0b10)\000"
 .LASF798:
 	.ascii	"SCNd64 __SCN64(d)\000"
@@ -4708,9 +4772,9 @@ usart2_write:
 	.ascii	"__thumb2__ 1\000"
 .LASF321:
 	.ascii	"__ULLACCUM_FBIT__ 32\000"
-.LASF897:
+.LASF910:
 	.ascii	"RCC_APB1ENR_PWREN_BIT 28\000"
-.LASF900:
+.LASF913:
 	.ascii	"RCC_APB1ENR_USART2EN_ENABLE (1 << RCC_APB1ENR_USART"
 	.ascii	"2EN_BIT)\000"
 .LASF366:
@@ -4721,13 +4785,13 @@ usart2_write:
 	.ascii	"SCNxLEAST64 __SCN64LEAST(x)\000"
 .LASF770:
 	.ascii	"SCNdLEAST32 __SCN32LEAST(d)\000"
-.LASF977:
+.LASF994:
 	.ascii	"RESERVED3\000"
 .LASF22:
 	.ascii	"__SIZEOF_LONG_DOUBLE__ 8\000"
-.LASF983:
+.LASF1000:
 	.ascii	"RESERVED5\000"
-.LASF896:
+.LASF909:
 	.ascii	"RCC_AHB1ENR_GPIOAEN_ENABLE (1 << RCC_AHB1ENR_GPIOAE"
 	.ascii	"N_BIT)\000"
 .LASF386:
@@ -4748,9 +4812,9 @@ usart2_write:
 	.ascii	"__need_wchar_t \000"
 .LASF66:
 	.ascii	"__UINT_FAST64_TYPE__ long long unsigned int\000"
-.LASF931:
+.LASF948:
 	.ascii	"USART2_BASE_ADDR (0x40004400U)\000"
-.LASF889:
+.LASF902:
 	.ascii	"RCC_CFGR_SWS_BIT 2\000"
 .LASF593:
 	.ascii	"INT_LEAST8_MAX (__INT_LEAST8_MAX__)\000"
@@ -4770,7 +4834,7 @@ usart2_write:
 	.ascii	"__FLT32_IS_IEC_60559__ 2\000"
 .LASF630:
 	.ascii	"SIG_ATOMIC_MAX (__STDINT_EXP(INT_MAX))\000"
-.LASF946:
+.LASF963:
 	.ascii	"USART_CR1_RE_ENABLE (1 << USART_CR1_RE_BIT)\000"
 .LASF725:
 	.ascii	"PRIdLEAST16 __PRI16LEAST(d)\000"
@@ -4780,7 +4844,7 @@ usart2_write:
 	.ascii	"__SCN64(x) __INT64 __STRINGIFY(x)\000"
 .LASF647:
 	.ascii	"_GCC_WRAP_STDINT_H \000"
-.LASF973:
+.LASF990:
 	.ascii	"AHB2ENR\000"
 .LASF805:
 	.ascii	"PRIoLEAST64 __PRI64LEAST(o)\000"
@@ -4804,11 +4868,13 @@ usart2_write:
 	.ascii	"__int8_t_defined 1\000"
 .LASF176:
 	.ascii	"__DBL_HAS_DENORM__ 1\000"
+.LASF885:
+	.ascii	"RCC_CFGR_MCO1_HSE (0b10)\000"
 .LASF625:
 	.ascii	"INTMAX_MAX (__INTMAX_MAX__)\000"
 .LASF602:
 	.ascii	"INT32_MAX (__INT32_MAX__)\000"
-.LASF926:
+.LASF943:
 	.ascii	"BIT(x) (1 << x)\000"
 .LASF470:
 	.ascii	"_MB_LEN_MAX 8\000"
@@ -4820,13 +4886,13 @@ usart2_write:
 	.ascii	"__FLT_DENORM_MIN__ 1.4012984643248171e-45F\000"
 .LASF534:
 	.ascii	"__LEAST8 \"hh\"\000"
-.LASF885:
+.LASF898:
 	.ascii	"RCC_CFGR_HPRE_DIV_NONE 0\000"
 .LASF540:
 	.ascii	"_END_STD_C \000"
-.LASF906:
+.LASF919:
 	.ascii	"true ((_Bool)+1u)\000"
-.LASF918:
+.LASF935:
 	.ascii	"GPIO_AFRL_AFRL3_MASK (0b1111)\000"
 .LASF600:
 	.ascii	"UINT_LEAST16_MAX (__UINT_LEAST16_MAX__)\000"
@@ -4836,13 +4902,13 @@ usart2_write:
 	.ascii	"PRIiLEAST16 __PRI16LEAST(i)\000"
 .LASF303:
 	.ascii	"__UACCUM_MIN__ 0.0UK\000"
-.LASF870:
+.LASF873:
 	.ascii	"RCC_PLLCFGR_PLLP_BIT 16\000"
 .LASF157:
 	.ascii	"__FLT_EPSILON__ 1.1920928955078125e-7F\000"
 .LASF376:
 	.ascii	"__GCC_ATOMIC_SHORT_LOCK_FREE 2\000"
-.LASF927:
+.LASF944:
 	.ascii	"PIN(port,num) ((((port) - 'A') << 8) | num)\000"
 .LASF807:
 	.ascii	"PRIxLEAST64 __PRI64LEAST(x)\000"
@@ -4860,7 +4926,7 @@ usart2_write:
 	.ascii	"SCNdFAST64 __SCN64FAST(d)\000"
 .LASF604:
 	.ascii	"INT_LEAST32_MIN (-__INT_LEAST32_MAX__ - 1)\000"
-.LASF863:
+.LASF865:
 	.ascii	"RCC_CR_HSION_BIT 0\000"
 .LASF779:
 	.ascii	"PRIxFAST32 __PRI32FAST(x)\000"
@@ -4878,7 +4944,7 @@ usart2_write:
 	.ascii	"__ELF__ 1\000"
 .LASF689:
 	.ascii	"PRIuLEAST8 __PRI8LEAST(u)\000"
-.LASF984:
+.LASF1001:
 	.ascii	"BDCR\000"
 .LASF211:
 	.ascii	"__FLT32_HAS_QUIET_NAN__ 1\000"
@@ -4910,7 +4976,7 @@ usart2_write:
 	.ascii	"__FP_FAST_FMAF 1\000"
 .LASF629:
 	.ascii	"SIG_ATOMIC_MIN (-__STDINT_EXP(INT_MAX) - 1)\000"
-.LASF860:
+.LASF862:
 	.ascii	"RCC_CR_HSEON_ON (1 << RCC_CR_HSEON_BIT)\000"
 .LASF565:
 	.ascii	"_INT16_T_DECLARED \000"
@@ -4934,13 +5000,15 @@ usart2_write:
 	.ascii	"__ARM_FEATURE_FP16_FML\000"
 .LASF803:
 	.ascii	"PRIdLEAST64 __PRI64LEAST(d)\000"
+.LASF924:
+	.ascii	"GPIO_MODER_AF_MODE (0b10)\000"
 .LASF255:
 	.ascii	"__USFRACT_EPSILON__ 0x1P-8UHR\000"
-.LASF858:
+.LASF860:
 	.ascii	"RCC_CR_HSERDY_READY (1 << RCC_CR_HSERDY_BIT)\000"
 .LASF763:
 	.ascii	"SCNx32 __SCN32(x)\000"
-.LASF965:
+.LASF982:
 	.ascii	"CFGR\000"
 .LASF558:
 	.ascii	"___int_least32_t_defined 1\000"
@@ -4948,7 +5016,7 @@ usart2_write:
 	.ascii	"__LLACCUM_MAX__ 0X7FFFFFFFFFFFFFFFP-31LLK\000"
 .LASF667:
 	.ascii	"__need_NULL\000"
-.LASF940:
+.LASF957:
 	.ascii	"USART_CR1_OVER8_8 (1 << USART_CR1_OVER8_BIT)\000"
 .LASF363:
 	.ascii	"__USER_LABEL_PREFIX__ \000"
@@ -4962,7 +5030,7 @@ usart2_write:
 	.ascii	"INT64_C(x) __INT64_C(x)\000"
 .LASF616:
 	.ascii	"INT_FAST16_MIN (-__INT_FAST16_MAX__ - 1)\000"
-.LASF915:
+.LASF930:
 	.ascii	"GPIO_MODER_MODER2_MASK (0b11)\000"
 .LASF106:
 	.ascii	"__INT_LEAST8_MAX__ 0x7f\000"
@@ -4992,6 +5060,8 @@ usart2_write:
 	.ascii	"__PRI8LEAST(x) __LEAST8 __STRINGIFY(x)\000"
 .LASF174:
 	.ascii	"__DBL_EPSILON__ ((double)2.2204460492503131e-16L)\000"
+.LASF926:
+	.ascii	"GPIO_MODER_MODER8_MASK (0b11)\000"
 .LASF268:
 	.ascii	"__LFRACT_MIN__ (-0.5LR-0.5LR)\000"
 .LASF117:
@@ -5014,7 +5084,7 @@ usart2_write:
 	.ascii	"___int8_t_defined 1\000"
 .LASF248:
 	.ascii	"__SFRACT_MIN__ (-0.5HR-0.5HR)\000"
-.LASF958:
+.LASF975:
 	.ascii	"long unsigned int\000"
 .LASF349:
 	.ascii	"__SA_IBIT__ 16\000"
@@ -5030,9 +5100,9 @@ usart2_write:
 	.ascii	"__ARM_FP16_FORMAT_IEEE\000"
 .LASF48:
 	.ascii	"__UINT16_TYPE__ short unsigned int\000"
-.LASF868:
+.LASF870:
 	.ascii	"RCC_PLLCFGR_PLLSRC_BIT 22\000"
-.LASF907:
+.LASF920:
 	.ascii	"false ((_Bool)+0u)\000"
 .LASF657:
 	.ascii	"_WCHAR_T_DEFINED_ \000"
@@ -5080,21 +5150,21 @@ usart2_write:
 	.ascii	"__USFRACT_FBIT__ 8\000"
 .LASF191:
 	.ascii	"__LDBL_EPSILON__ 2.2204460492503131e-16L\000"
-.LASF910:
+.LASF923:
 	.ascii	"GPIOA ((struct gpio *) GPIOA_BASE_ADDR)\000"
 .LASF730:
 	.ascii	"PRIXLEAST16 __PRI16LEAST(X)\000"
 .LASF623:
 	.ascii	"INT_FAST64_MAX (__INT_FAST64_MAX__)\000"
-.LASF945:
+.LASF962:
 	.ascii	"USART_CR1_RE_BIT 2\000"
 .LASF373:
 	.ascii	"__GCC_ATOMIC_CHAR16_T_LOCK_FREE 2\000"
 .LASF790:
 	.ascii	"__PRI64FAST(x) __FAST64 __STRINGIFY(x)\000"
-.LASF892:
+.LASF905:
 	.ascii	"RCC_CFGR_SW_BIT 0\000"
-.LASF995:
+.LASF1012:
 	.ascii	"LCKR\000"
 .LASF168:
 	.ascii	"__DBL_MAX_EXP__ 1024\000"
@@ -5142,11 +5212,11 @@ usart2_write:
 	.ascii	"PRIX32 __PRI32(X)\000"
 .LASF774:
 	.ascii	"SCNxLEAST32 __SCN32LEAST(x)\000"
-.LASF992:
+.LASF1009:
 	.ascii	"OSPEEDR\000"
 .LASF712:
 	.ascii	"__SCN16LEAST(x) __LEAST16 __STRINGIFY(x)\000"
-.LASF964:
+.LASF981:
 	.ascii	"PLLCFGR\000"
 .LASF5:
 	.ascii	"__GNUC__ 12\000"
@@ -5174,7 +5244,7 @@ usart2_write:
 	.ascii	"__ULACCUM_MIN__ 0.0ULK\000"
 .LASF462:
 	.ascii	"_ATEXIT_DYNAMIC_ALLOC 1\000"
-.LASF957:
+.LASF974:
 	.ascii	"__uint32_t\000"
 .LASF188:
 	.ascii	"__LDBL_MAX__ 1.7976931348623157e+308L\000"
@@ -5184,7 +5254,7 @@ usart2_write:
 	.ascii	"__FLT_RADIX__ 2\000"
 .LASF455:
 	.ascii	"_INTTYPES_H \000"
-.LASF959:
+.LASF976:
 	.ascii	"long long int\000"
 .LASF401:
 	.ascii	"__ARM_FEATURE_CMSE\000"
@@ -5202,7 +5272,7 @@ usart2_write:
 	.ascii	"WINT_MAX (__WINT_MAX__)\000"
 .LASF823:
 	.ascii	"SCNuFAST64 __SCN64FAST(u)\000"
-.LASF986:
+.LASF1003:
 	.ascii	"SSCGR\000"
 .LASF137:
 	.ascii	"__UINT_FAST64_MAX__ 0xffffffffffffffffULL\000"
@@ -5216,7 +5286,7 @@ usart2_write:
 	.ascii	"__INTPTR_WIDTH__ 32\000"
 .LASF379:
 	.ascii	"__GCC_ATOMIC_LLONG_LOCK_FREE 1\000"
-.LASF933:
+.LASF950:
 	.ascii	"USART_SR_TXE_BIT 7\000"
 .LASF239:
 	.ascii	"__FLT32X_MIN__ 2.2250738585072014e-308F32x\000"
@@ -5226,13 +5296,13 @@ usart2_write:
 	.ascii	"__WCHAR_T \000"
 .LASF223:
 	.ascii	"__FLT64_MIN__ 2.2250738585072014e-308F64\000"
-.LASF999:
+.LASF1016:
 	.ascii	"GTPR\000"
 .LASF554:
 	.ascii	"___int32_t_defined 1\000"
 .LASF83:
 	.ascii	"__INT_WIDTH__ 32\000"
-.LASF970:
+.LASF987:
 	.ascii	"APB2RSTR\000"
 .LASF409:
 	.ascii	"__ARM_ARCH_PROFILE\000"
@@ -5284,7 +5354,7 @@ usart2_write:
 	.ascii	"__ARM_NEON_FP\000"
 .LASF280:
 	.ascii	"__LLFRACT_EPSILON__ 0x1P-63LLR\000"
-.LASF982:
+.LASF999:
 	.ascii	"APB2LPENR\000"
 .LASF821:
 	.ascii	"SCNiFAST64 __SCN64FAST(i)\000"
@@ -5292,11 +5362,11 @@ usart2_write:
 	.ascii	"_ANSIDECL_H_ \000"
 .LASF684:
 	.ascii	"SCNu8 __SCN8(u)\000"
-.LASF904:
+.LASF917:
 	.ascii	"_STDBOOL_H \000"
 .LASF261:
 	.ascii	"__UFRACT_FBIT__ 16\000"
-.LASF939:
+.LASF956:
 	.ascii	"USART_CR1_OVER8_BIT 15\000"
 .LASF342:
 	.ascii	"__UDQ_FBIT__ 64\000"
@@ -5305,22 +5375,24 @@ usart2_write:
 	.ascii	"\000"
 .LASF583:
 	.ascii	"__int_fast16_t_defined 1\000"
-.LASF990:
+.LASF1007:
 	.ascii	"MODER\000"
 .LASF483:
 	.ascii	"__FLOAT_TYPE float\000"
 .LASF185:
 	.ascii	"__LDBL_MAX_10_EXP__ 308\000"
+.LASF933:
+	.ascii	"GPIO_AFRH_AFRH8_MCO_1 (0b0000)\000"
 .LASF175:
 	.ascii	"__DBL_DENORM_MIN__ ((double)4.9406564584124654e-324"
 	.ascii	"L)\000"
 .LASF608:
 	.ascii	"INT64_MAX (__INT64_MAX__)\000"
-.LASF961:
+.LASF978:
 	.ascii	"unsigned int\000"
-.LASF857:
+.LASF859:
 	.ascii	"RCC_CR_HSERDY_BIT 17\000"
-.LASF924:
+.LASF941:
 	.ascii	"GPIO_PORT_OFFSET (0x400U)\000"
 .LASF460:
 	.ascii	"__NEWLIB_MINOR__ 3\000"
@@ -5346,11 +5418,11 @@ usart2_write:
 	.ascii	"_WCHAR_T_DECLARED \000"
 .LASF24:
 	.ascii	"__CHAR_BIT__ 8\000"
-.LASF919:
+.LASF936:
 	.ascii	"GPIO_AFRL_AFRL3_USART2_RX (0b0111)\000"
 .LASF143:
 	.ascii	"__FLT_EVAL_METHOD__ 0\000"
-.LASF953:
+.LASF970:
 	.ascii	"short int\000"
 .LASF686:
 	.ascii	"PRIdLEAST8 __PRI8LEAST(d)\000"
@@ -5362,9 +5434,11 @@ usart2_write:
 	.ascii	"__INT_FAST8_WIDTH__ 32\000"
 .LASF2:
 	.ascii	"__STDC_UTF_16__ 1\000"
+.LASF892:
+	.ascii	"RCC_CFGR_MCO1PRE_BIT 24\000"
 .LASF402:
 	.ascii	"__ARM_FEATURE_LDREX\000"
-.LASF1002:
+.LASF1019:
 	.ascii	"usart2_start\000"
 .LASF336:
 	.ascii	"__UQQ_FBIT__ 8\000"
@@ -5394,13 +5468,13 @@ usart2_write:
 	.ascii	"__ARM_FEATURE_COPROC 15\000"
 .LASF484:
 	.ascii	"__OBSOLETE_MATH_DEFAULT 1\000"
-.LASF864:
+.LASF866:
 	.ascii	"RCC_CR_HSION_ON (1 << RCC_CR_HSION_BIT)\000"
 .LASF671:
 	.ascii	"__PRI8FAST(x) __FAST8 __STRINGIFY(x)\000"
 .LASF82:
 	.ascii	"__SHRT_WIDTH__ 16\000"
-.LASF880:
+.LASF883:
 	.ascii	"RCC_CFGR_PPRE_DIV_2 (0b100)\000"
 .LASF473:
 	.ascii	"_UNBUF_STREAM_OPT 1\000"
@@ -5408,11 +5482,11 @@ usart2_write:
 	.ascii	"__STRINGIFY(a) #a\000"
 .LASF356:
 	.ascii	"__USA_FBIT__ 16\000"
-.LASF981:
+.LASF998:
 	.ascii	"APB1LPENR\000"
 .LASF480:
 	.ascii	"__IEEE_LITTLE_ENDIAN \000"
-.LASF922:
+.LASF939:
 	.ascii	"GPIO_AFRL_AFRL2_USART2_TX (0b0111)\000"
 .LASF183:
 	.ascii	"__LDBL_MIN_10_EXP__ (-307)\000"
@@ -5424,6 +5498,8 @@ usart2_write:
 	.ascii	"__ATFILE_VISIBLE 0\000"
 .LASF372:
 	.ascii	"__GCC_ATOMIC_CHAR_LOCK_FREE 2\000"
+.LASF925:
+	.ascii	"GPIO_MODER_MODER8_BIT 16\000"
 .LASF270:
 	.ascii	"__LFRACT_EPSILON__ 0x1P-31LR\000"
 .LASF809:
@@ -5440,6 +5516,9 @@ usart2_write:
 	.ascii	"PRIuLEAST32 __PRI32LEAST(u)\000"
 .LASF407:
 	.ascii	"__ARM_SIZEOF_MINIMAL_ENUM 1\000"
+.LASF872:
+	.ascii	"RCC_PLLCFGR_PLLSRC_HSI (0 << RCC_PLLCFGR_PLLSRC_BIT"
+	.ascii	")\000"
 .LASF499:
 	.ascii	"_POINTER_INT long\000"
 .LASF238:
@@ -5472,7 +5551,7 @@ usart2_write:
 	.ascii	"__SCN16FAST(x) __FAST16 __STRINGIFY(x)\000"
 .LASF537:
 	.ascii	"__LEAST64 \"ll\"\000"
-.LASF862:
+.LASF864:
 	.ascii	"RCC_CR_HSIRDY_READY (1 << RCC_CR_HSIRDY_BIT)\000"
 .LASF659:
 	.ascii	"_WCHAR_T_H \000"
@@ -5486,7 +5565,7 @@ usart2_write:
 	.ascii	"_HAVE_CC_INHIBIT_LOOP_TO_LIBCALL 1\000"
 .LASF420:
 	.ascii	"__ARM_ARCH_ISA_THUMB 2\000"
-.LASF895:
+.LASF908:
 	.ascii	"RCC_AHB1ENR_GPIOAEN_BIT 0\000"
 .LASF458:
 	.ascii	"_NEWLIB_VERSION \"4.3.0\"\000"
@@ -5496,6 +5575,8 @@ usart2_write:
 	.ascii	"_FSEEK_OPTIMIZATION 1\000"
 .LASF87:
 	.ascii	"__WINT_WIDTH__ 32\000"
+.LASF857:
+	.ascii	"RCC_CR_CSS_BIT 19\000"
 .LASF515:
 	.ascii	"long\000"
 .LASF65:
@@ -5504,7 +5585,7 @@ usart2_write:
 	.ascii	"__UFRACT_IBIT__ 0\000"
 .LASF399:
 	.ascii	"__ARM_32BIT_STATE 1\000"
-.LASF914:
+.LASF929:
 	.ascii	"GPIO_MODER_MODER2_BIT 4\000"
 .LASF107:
 	.ascii	"__INT8_C(c) c\000"
@@ -5512,7 +5593,7 @@ usart2_write:
 	.ascii	"__LFRACT_IBIT__ 0\000"
 .LASF16:
 	.ascii	"__SIZEOF_INT__ 4\000"
-.LASF944:
+.LASF961:
 	.ascii	"USART_CR1_TE_ENABLE (1 << USART_CR1_TE_BIT)\000"
 .LASF166:
 	.ascii	"__DBL_MIN_EXP__ (-1021)\000"
@@ -5522,17 +5603,19 @@ usart2_write:
 	.ascii	"SCNuFAST16 __SCN16FAST(u)\000"
 .LASF802:
 	.ascii	"SCNx64 __SCN64(x)\000"
-.LASF929:
+.LASF946:
 	.ascii	"PINPORT(pin) (pin >> 8)\000"
 .LASF198:
 	.ascii	"__FLT32_DIG__ 6\000"
-.LASF899:
+.LASF890:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV4 (0b110)\000"
+.LASF912:
 	.ascii	"RCC_APB1ENR_USART2EN_BIT 17\000"
-.LASF884:
+.LASF897:
 	.ascii	"RCC_CFGR_PPRE1_MASK (0b111)\000"
 .LASF646:
 	.ascii	"UINTMAX_C(x) __UINTMAX_C(x)\000"
-.LASF912:
+.LASF928:
 	.ascii	"GPIO_MODER_MODER3_MASK (0b11)\000"
 .LASF624:
 	.ascii	"UINT_FAST64_MAX (__UINT_FAST64_MAX__)\000"
@@ -5546,22 +5629,24 @@ usart2_write:
 	.ascii	"__SACCUM_FBIT__ 7\000"
 .LASF734:
 	.ascii	"SCNuLEAST16 __SCN16LEAST(u)\000"
-.LASF969:
+.LASF986:
 	.ascii	"APB1RSTR\000"
 .LASF298:
 	.ascii	"__ACCUM_MIN__ (-0X1P15K-0X1P15K)\000"
 .LASF393:
 	.ascii	"__ARM_FEATURE_CRYPTO\000"
-.LASF975:
+.LASF992:
 	.ascii	"APB1ENR\000"
 .LASF698:
 	.ascii	"PRIiFAST8 __PRI8FAST(i)\000"
 .LASF742:
 	.ascii	"SCNdFAST16 __SCN16FAST(d)\000"
-.LASF867:
+.LASF887:
+	.ascii	"RCC_CFGR_MCO1_BIT 21\000"
+.LASF869:
 	.ascii	"RCC_PLLCFGR_PLLQ(q) ((q & RCC_PLLCFGR_PLLQ_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLQ_BIT)\000"
-.LASF934:
+.LASF951:
 	.ascii	"USART_SR_TXE_TRANSMITTED (1 << USART_SR_TXE_BIT)\000"
 .LASF788:
 	.ascii	"__PRI64LEAST(x) __LEAST64 __STRINGIFY(x)\000"
@@ -5581,18 +5666,18 @@ usart2_write:
 	.ascii	"__NEWLIB_PATCHLEVEL__ 0\000"
 .LASF26:
 	.ascii	"__ORDER_LITTLE_ENDIAN__ 1234\000"
-.LASF869:
+.LASF871:
 	.ascii	"RCC_PLLCFGR_PLLSRC_HSE (1 << RCC_PLLCFGR_PLLSRC_BIT"
 	.ascii	")\000"
 .LASF155:
 	.ascii	"__FLT_NORM_MAX__ 3.4028234663852886e+38F\000"
-.LASF960:
+.LASF977:
 	.ascii	"long long unsigned int\000"
 .LASF612:
 	.ascii	"UINT_LEAST64_MAX (__UINT_LEAST64_MAX__)\000"
 .LASF150:
 	.ascii	"__FLT_MIN_10_EXP__ (-37)\000"
-.LASF890:
+.LASF903:
 	.ascii	"RCC_CFGR_SWS_MASK (0b11)\000"
 .LASF312:
 	.ascii	"__ULACCUM_IBIT__ 32\000"
@@ -5618,6 +5703,8 @@ usart2_write:
 	.ascii	"SCNdFAST32 __SCN32FAST(d)\000"
 .LASF339:
 	.ascii	"__UHQ_IBIT__ 0\000"
+.LASF927:
+	.ascii	"GPIO_MODER_MODER3_BIT 6\000"
 .LASF370:
 	.ascii	"__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1\000"
 .LASF60:
@@ -5630,7 +5717,7 @@ usart2_write:
 	.ascii	"__SACCUM_MIN__ (-0X1P7HK-0X1P7HK)\000"
 .LASF274:
 	.ascii	"__ULFRACT_MAX__ 0XFFFFFFFFP-32ULR\000"
-.LASF875:
+.LASF878:
 	.ascii	"RCC_PLLCFGR_PLLN(n) ((n & RCC_PLLCFGR_PLLN_MASK) <<"
 	.ascii	" RCC_PLLCFGR_PLLN_BIT)\000"
 .LASF56:
@@ -5641,7 +5728,7 @@ usart2_write:
 	.ascii	"__LACCUM_MAX__ 0X7FFFFFFFFFFFFFFFP-31LK\000"
 .LASF40:
 	.ascii	"__CHAR16_TYPE__ short unsigned int\000"
-.LASF936:
+.LASF953:
 	.ascii	"USART_SR_TC_COMPLETED (1 << USART_SR_TC_BIT)\000"
 .LASF231:
 	.ascii	"__FLT32X_DIG__ 15\000"
@@ -5675,11 +5762,11 @@ usart2_write:
 	.ascii	"SCNdFAST8 __SCN8FAST(d)\000"
 .LASF577:
 	.ascii	"_UINTPTR_T_DECLARED \000"
-.LASF997:
+.LASF1014:
 	.ascii	"AFRH\000"
 .LASF314:
 	.ascii	"__ULACCUM_MAX__ 0XFFFFFFFFFFFFFFFFP-32ULK\000"
-.LASF996:
+.LASF1013:
 	.ascii	"AFRL\000"
 .LASF273:
 	.ascii	"__ULFRACT_MIN__ 0.0ULR\000"
@@ -5687,6 +5774,8 @@ usart2_write:
 	.ascii	"SIZE_MAX (__SIZE_MAX__)\000"
 .LASF333:
 	.ascii	"__DQ_IBIT__ 0\000"
+.LASF893:
+	.ascii	"RCC_CFGR_MCO1PRE_MASK (0b111)\000"
 .LASF450:
 	.ascii	"__ARM_BF16_FORMAT_ALTERNATIVE\000"
 .LASF45:
@@ -5705,13 +5794,10 @@ usart2_write:
 	.ascii	"__SCN32(x) __INT32 __STRINGIFY(x)\000"
 .LASF744:
 	.ascii	"SCNoFAST16 __SCN16FAST(o)\000"
-.LASF1003:
+.LASF1020:
 	.ascii	"usart2_init\000"
 .LASF345:
 	.ascii	"__UTQ_IBIT__ 0\000"
-.LASF925:
-	.ascii	"GPIO(port) ((struct gpio*)(uintptr_t)(GPIO_BASE_ADD"
-	.ascii	"R + (GPIO_PORT_OFFSET * port)))\000"
 .LASF348:
 	.ascii	"__SA_FBIT__ 15\000"
 .LASF661:
@@ -5736,7 +5822,7 @@ usart2_write:
 	.ascii	"PRIi16 __PRI16(i)\000"
 .LASF390:
 	.ascii	"__ARM_FEATURE_DSP 1\000"
-.LASF942:
+.LASF959:
 	.ascii	"USART_CR1_UE_ENABLE (1 << USART_CR1_UE_BIT)\000"
 .LASF826:
 	.ascii	"__SCNMAX(x) __STRINGIFY(ll ##x)\000"
@@ -5744,7 +5830,7 @@ usart2_write:
 	.ascii	"__QQ_IBIT__ 0\000"
 .LASF764:
 	.ascii	"PRIdLEAST32 __PRI32LEAST(d)\000"
-.LASF991:
+.LASF1008:
 	.ascii	"OTYPER\000"
 .LASF812:
 	.ascii	"SCNuLEAST64 __SCN64LEAST(u)\000"
@@ -5766,21 +5852,21 @@ usart2_write:
 	.ascii	"RCC_H_ \000"
 .LASF405:
 	.ascii	"__ARM_FEATURE_NUMERIC_MAXMIN\000"
-.LASF923:
+.LASF940:
 	.ascii	"GPIO_BASE_ADDR (0x40020000U)\000"
 .LASF38:
 	.ascii	"__INTMAX_TYPE__ long long int\000"
 .LASF512:
 	.ascii	"short\000"
-.LASF948:
+.LASF965:
 	.ascii	"USART_BRR_MANTISSA_MASK (0b111111111111)\000"
-.LASF937:
+.LASF954:
 	.ascii	"USART_SR_RXNE_BIT 5\000"
 .LASF436:
 	.ascii	"__ARM_ARCH_7EM__ 1\000"
 .LASF428:
 	.ascii	"__ARM_FEATURE_FP16_SCALAR_ARITHMETIC\000"
-.LASF972:
+.LASF989:
 	.ascii	"AHB1ENR\000"
 .LASF295:
 	.ascii	"__USACCUM_EPSILON__ 0x1P-8UHK\000"
@@ -5820,11 +5906,11 @@ usart2_write:
 	.ascii	"__DBL_DIG__ 15\000"
 .LASF275:
 	.ascii	"__ULFRACT_EPSILON__ 0x1P-32ULR\000"
-.LASF967:
+.LASF984:
 	.ascii	"AHB2RSTR\000"
 .LASF672:
 	.ascii	"__SCN8(x) __INT8 __STRINGIFY(x)\000"
-.LASF882:
+.LASF895:
 	.ascii	"RCC_CFGR_PPRE2_MASK (0b111)\000"
 .LASF23:
 	.ascii	"__SIZEOF_SIZE_T__ 4\000"
@@ -5840,7 +5926,7 @@ usart2_write:
 	.ascii	"_FVWRITE_IN_STREAMIO 1\000"
 .LASF833:
 	.ascii	"SCNdMAX __SCNMAX(d)\000"
-.LASF920:
+.LASF937:
 	.ascii	"GPIO_AFRL_AFRL2_BIT 8\000"
 .LASF190:
 	.ascii	"__LDBL_MIN__ 2.2250738585072014e-308L\000"
@@ -5852,11 +5938,11 @@ usart2_write:
 	.ascii	"unsigned\000"
 .LASF381:
 	.ascii	"__GCC_DESTRUCTIVE_SIZE 64\000"
-.LASF993:
+.LASF1010:
 	.ascii	"PUPDR\000"
 .LASF836:
 	.ascii	"SCNuMAX __SCNMAX(u)\000"
-.LASF932:
+.LASF949:
 	.ascii	"USART2 ((struct usart *) USART2_BASE_ADDR)\000"
 .LASF121:
 	.ascii	"__UINT16_C(c) c\000"
@@ -5864,12 +5950,12 @@ usart2_write:
 	.ascii	"__UDA_IBIT__ 32\000"
 .LASF535:
 	.ascii	"__LEAST16 \"h\"\000"
-.LASF877:
+.LASF880:
 	.ascii	"RCC_PLLCFGR_PLLM_MASK (0b111111)\000"
 .LASF587:
 	.ascii	"INTPTR_MAX (__INTPTR_MAX__)\000"
-.LASF935:
-	.ascii	"USART_SR_TC_BIT 6\000"
+.LASF884:
+	.ascii	"RCC_CFGR_MCO1_HSI (0b00)\000"
 .LASF711:
 	.ascii	"__SCN16(x) __INT16 __STRINGIFY(x)\000"
 .LASF607:
@@ -5886,6 +5972,8 @@ usart2_write:
 	.ascii	"__SIG_ATOMIC_MAX__ 0x7fffffff\000"
 .LASF609:
 	.ascii	"UINT64_MAX (__UINT64_MAX__)\000"
+.LASF932:
+	.ascii	"GPIO_AFRH_AFRH8_MASK (0b1111)\000"
 .LASF472:
 	.ascii	"_RETARGETABLE_LOCKING 1\000"
 .LASF440:
@@ -5910,7 +5998,7 @@ usart2_write:
 	.ascii	"__INT16_MAX__ 0x7fff\000"
 .LASF479:
 	.ascii	"__SYS_CONFIG_H__ \000"
-.LASF876:
+.LASF879:
 	.ascii	"RCC_PLLCFGR_PLLM_BIT 0\000"
 .LASF8:
 	.ascii	"__VERSION__ \"12.3.1 20230626\"\000"
@@ -5920,7 +6008,7 @@ usart2_write:
 	.ascii	"__FAST8 \000"
 .LASF497:
 	.ascii	"__XSI_VISIBLE 0\000"
-.LASF994:
+.LASF1011:
 	.ascii	"BSRR\000"
 .LASF795:
 	.ascii	"PRIu64 __PRI64(u)\000"
@@ -5946,7 +6034,7 @@ usart2_write:
 	.ascii	"PRIdMAX __PRIMAX(d)\000"
 .LASF388:
 	.ascii	"__SIZEOF_WINT_T__ 4\000"
-.LASF881:
+.LASF894:
 	.ascii	"RCC_CFGR_PPRE2_BIT 13\000"
 .LASF783:
 	.ascii	"SCNoFAST32 __SCN32FAST(o)\000"
@@ -5958,6 +6046,9 @@ usart2_write:
 	.ascii	"__LDBL_DECIMAL_DIG__ 17\000"
 .LASF702:
 	.ascii	"PRIXFAST8 __PRI8FAST(X)\000"
+.LASF907:
+	.ascii	"RCC_CFGR_SW(clock) ((clock & RCC_CFGR_SW_MASK) << R"
+	.ascii	"CC_CFGR_SW_BIT)\000"
 .LASF308:
 	.ascii	"__LACCUM_MIN__ (-0X1P31LK-0X1P31LK)\000"
 .LASF785:
@@ -6004,7 +6095,7 @@ usart2_write:
 	.ascii	"__GCC_CONSTRUCTIVE_SIZE 64\000"
 .LASF665:
 	.ascii	"_BSD_WCHAR_T_\000"
-.LASF987:
+.LASF1004:
 	.ascii	"PLLI2SCFGR\000"
 .LASF277:
 	.ascii	"__LLFRACT_IBIT__ 0\000"
@@ -6014,9 +6105,9 @@ usart2_write:
 	.ascii	"PRIx32 __PRI32(x)\000"
 .LASF278:
 	.ascii	"__LLFRACT_MIN__ (-0.5LLR-0.5LLR)\000"
-.LASF963:
+.LASF980:
 	.ascii	"uint32_t\000"
-.LASF873:
+.LASF876:
 	.ascii	"RCC_PLLCFGR_PLLN_BIT 6\000"
 .LASF690:
 	.ascii	"PRIxLEAST8 __PRI8LEAST(x)\000"
@@ -6050,9 +6141,11 @@ usart2_write:
 	.ascii	"__ULACCUM_EPSILON__ 0x1P-32ULK\000"
 .LASF181:
 	.ascii	"__LDBL_DIG__ 15\000"
+.LASF889:
+	.ascii	"RCC_CFGR_MCO1PRE_DIV5 (0b111)\000"
 .LASF89:
 	.ascii	"__SIZE_WIDTH__ 32\000"
-.LASF871:
+.LASF874:
 	.ascii	"RCC_PLLCFGR_PLLP_MASK (0b11)\000"
 .LASF481:
 	.ascii	"_SUPPORTS_ERREXCEPT \000"
@@ -6068,13 +6161,13 @@ usart2_write:
 	.ascii	"__INT_LEAST16_TYPE__ short int\000"
 .LASF326:
 	.ascii	"__QQ_FBIT__ 7\000"
-.LASF928:
+.LASF945:
 	.ascii	"PINNUM(pin) (pin & 0b1111)\000"
 .LASF769:
 	.ascii	"PRIXLEAST32 __PRI32LEAST(X)\000"
 .LASF171:
 	.ascii	"__DBL_MAX__ ((double)1.7976931348623157e+308L)\000"
-.LASF954:
+.LASF971:
 	.ascii	"short unsigned int\000"
 .LASF276:
 	.ascii	"__LLFRACT_FBIT__ 63\000"
@@ -6082,7 +6175,7 @@ usart2_write:
 	.ascii	"__FLT32_HAS_INFINITY__ 1\000"
 .LASF416:
 	.ascii	"__thumb__ 1\000"
-.LASF947:
+.LASF964:
 	.ascii	"USART_BRR_MANTISSA_BIT 4\000"
 .LASF421:
 	.ascii	"__ARMEL__ 1\000"
@@ -6090,22 +6183,25 @@ usart2_write:
 	.ascii	"PRIXLEAST8 __PRI8LEAST(X)\000"
 .LASF328:
 	.ascii	"__HQ_FBIT__ 15\000"
-.LASF908:
+.LASF921:
 	.ascii	"__bool_true_false_are_defined 1\000"
-.LASF941:
+.LASF958:
 	.ascii	"USART_CR1_UE_BIT 13\000"
-.LASF911:
-	.ascii	"GPIO_MODER_MODER3_BIT 7\000"
+.LASF942:
+	.ascii	"GPIO(port) ((struct gpio*)(uintptr_t)(GPIO_BASE_ADD"
+	.ascii	"R + (GPIO_PORT_OFFSET * port)))\000"
 .LASF799:
 	.ascii	"SCNi64 __SCN64(i)\000"
-.LASF861:
+.LASF863:
 	.ascii	"RCC_CR_HSIRDY_BIT 1\000"
 .LASF80:
 	.ascii	"__SIZE_MAX__ 0xffffffffU\000"
-.LASF1000:
+.LASF1017:
 	.ascii	"usart2_write\000"
 .LASF819:
 	.ascii	"PRIXFAST64 __PRI64FAST(X)\000"
+.LASF858:
+	.ascii	"RCC_CR_CSS_ON (1 << RCC_CR_CSS_BIT)\000"
 .LASF412:
 	.ascii	"__ARM_ARCH\000"
 .LASF591:
@@ -6122,7 +6218,7 @@ usart2_write:
 	.ascii	"SCNuFAST32 __SCN32FAST(u)\000"
 .LASF523:
 	.ascii	"long +4\000"
-.LASF966:
+.LASF983:
 	.ascii	"AHB1RSTR\000"
 .LASF724:
 	.ascii	"SCNx16 __SCN16(x)\000"
@@ -6132,7 +6228,7 @@ usart2_write:
 	.ascii	"__SCN64LEAST(x) __LEAST64 __STRINGIFY(x)\000"
 .LASF340:
 	.ascii	"__USQ_FBIT__ 32\000"
-.LASF1006:
+.LASF1023:
 	.ascii	"/home/alex/code/own/stm32-falling-sand\000"
 .LASF797:
 	.ascii	"PRIX64 __PRI64(X)\000"
@@ -6172,7 +6268,7 @@ usart2_write:
 	.ascii	"__DBL_MIN_10_EXP__ (-307)\000"
 .LASF796:
 	.ascii	"PRIx64 __PRI64(x)\000"
-.LASF943:
+.LASF960:
 	.ascii	"USART_CR1_TE_BIT 3\000"
 .LASF513:
 	.ascii	"__int20\000"
@@ -6180,7 +6276,7 @@ usart2_write:
 	.ascii	"INT_FAST32_MAX (__INT_FAST32_MAX__)\000"
 .LASF205:
 	.ascii	"__FLT32_NORM_MAX__ 3.4028234663852886e+38F32\000"
-.LASF905:
+.LASF918:
 	.ascii	"bool _Bool\000"
 .LASF632:
 	.ascii	"PTRDIFF_MIN (-PTRDIFF_MAX - 1)\000"
@@ -6190,7 +6286,7 @@ usart2_write:
 	.ascii	"__DBL_MANT_DIG__ 53\000"
 .LASF272:
 	.ascii	"__ULFRACT_IBIT__ 0\000"
-.LASF887:
+.LASF900:
 	.ascii	"RCC_CFGR_HPRE_MASK (0b1111)\000"
 .LASF72:
 	.ascii	"__INT_MAX__ 0x7fffffff\000"
diff --git a/build/usart.i b/build/usart.i
index 4a86ecc..f246bca 100644
--- a/build/usart.i
+++ b/build/usart.i
@@ -2014,6 +2014,11 @@ struct rcc {
 #define RCC_CR_PLLON_ON (1 << RCC_CR_PLLON_BIT)
 
 
+#define RCC_CR_CSS_BIT 19
+#define RCC_CR_CSS_ON (1 << RCC_CR_CSS_BIT)
+
+
+
 #define RCC_CR_HSERDY_BIT 17
 #define RCC_CR_HSERDY_READY (1 << RCC_CR_HSERDY_BIT)
 
@@ -2036,6 +2041,7 @@ struct rcc {
 
 #define RCC_PLLCFGR_PLLSRC_BIT 22
 #define RCC_PLLCFGR_PLLSRC_HSE (1 << RCC_PLLCFGR_PLLSRC_BIT)
+#define RCC_PLLCFGR_PLLSRC_HSI (0 << RCC_PLLCFGR_PLLSRC_BIT)
 
 #define RCC_PLLCFGR_PLLP_BIT 16
 #define RCC_PLLCFGR_PLLP_MASK (0b11)
@@ -2055,6 +2061,21 @@ struct rcc {
 #define RCC_CFGR_PPRE_DIV_2 (0b100)
 
 
+#define RCC_CFGR_MCO1_HSI (0b00)
+#define RCC_CFGR_MCO1_HSE (0b10)
+#define RCC_CFGR_MCO1_PLL (0b11)
+
+#define RCC_CFGR_MCO1_BIT 21
+#define RCC_CFGR_MCO1_MASK (0b11)
+
+#define RCC_CFGR_MCO1PRE_DIV5 (0b111)
+#define RCC_CFGR_MCO1PRE_DIV4 (0b110)
+#define RCC_CFGR_MCO1PRE_DIV2 (0b100)
+
+#define RCC_CFGR_MCO1PRE_BIT 24
+#define RCC_CFGR_MCO1PRE_MASK (0b111)
+
+
 #define RCC_CFGR_PPRE2_BIT 13
 #define RCC_CFGR_PPRE2_MASK (0b111)
 
@@ -2075,6 +2096,7 @@ struct rcc {
 #define RCC_CFGR_SWS_MASK (0b11)
 
 
+#define RCC_CFGR_SW_PLL (0b10)
 #define RCC_CFGR_SW_PLL (0b10)
 
 #define RCC_CFGR_SW_BIT 0
@@ -2132,13 +2154,21 @@ struct gpio {
 #define GPIOA ((struct gpio *) GPIOA_BASE_ADDR)
 
 
-#define GPIO_MODER_MODER3_BIT 7
+#define GPIO_MODER_AF_MODE (0b10)
+
+#define GPIO_MODER_MODER8_BIT 16
+#define GPIO_MODER_MODER8_MASK (0b11)
+
+#define GPIO_MODER_MODER3_BIT 6
 #define GPIO_MODER_MODER3_MASK (0b11)
-#define GPIO_MODER_MODER3_AF (0b10)
 
 #define GPIO_MODER_MODER2_BIT 4
 #define GPIO_MODER_MODER2_MASK (0b11)
-#define GPIO_MODER_MODER2_AF (0b10)
+
+
+#define GPIO_AFRH_AFRH8_BIT 0
+#define GPIO_AFRH_AFRH8_MASK (0b1111)
+#define GPIO_AFRH_AFRH8_MCO_1 (0b0000)
 
 
 #define GPIO_AFRL_AFRL3_BIT 12
@@ -2173,9 +2203,9 @@ typedef enum {
 
 void gpio_set_mode(uint16_t pin, GPIO_MODE mode);
 void gpio_write(uint16_t pin, 
-# 64 "src/gpio.h" 3 4
+# 72 "src/gpio.h" 3 4
                              _Bool 
-# 64 "src/gpio.h"
+# 72 "src/gpio.h"
                                   val);
 # 3 "src/usart.c" 2
 # 1 "src/usart.h" 1
@@ -2250,8 +2280,8 @@ void usart2_init(void) {
 
   ((struct gpio *) (0x40020000U))->MODER &= ~((0b11) << 4);
   ((struct gpio *) (0x40020000U))->MODER |= ((0b10) << 4);
-  ((struct gpio *) (0x40020000U))->MODER &= ~((0b11) << 7);
-  ((struct gpio *) (0x40020000U))->MODER |= ((0b10) << 7);
+  ((struct gpio *) (0x40020000U))->MODER &= ~((0b11) << 6);
+  ((struct gpio *) (0x40020000U))->MODER |= ((0b10) << 6);
 
 
   ((struct gpio *) (0x40020000U))->AFRL &= ~((0b1111) << 8);
@@ -2260,19 +2290,22 @@ void usart2_init(void) {
   ((struct gpio *) (0x40020000U))->AFRL |= ((0b0111) << 12);
 
 
+  ((struct gpio *) (0x40020000U))->MODER &= ~((0b11) << 16);
+  ((struct gpio *) (0x40020000U))->MODER |= ((0b10) << 16);
+
+
+  ((struct gpio *) (0x40020000U))->AFRH &= ~((0b1111) << 0);
+  ((struct gpio *) (0x40020000U))->AFRH |= ((0b0000) << 0);
+
+
   ((struct rcc *) (0x40023800U))->APB1ENR |= (1 << 17);
 
 
   ((struct usart *) (0x40004400U))->CR1 = 0;
   ((struct usart *) (0x40004400U))->CR2 = 0;
   ((struct usart *) (0x40004400U))->CR3 = 0;
-# 54 "src/usart.c"
-  ((struct usart *) (0x40004400U))->BRR &= ~((0b111111111111) << 4);
-  ((struct usart *) (0x40004400U))->BRR |= (0x34 << 4);
-
-
-  ((struct usart *) (0x40004400U))->BRR &= ~((0b111) << 0);
-  ((struct usart *) (0x40004400U))->BRR |= (0x0 << 0);
+# 71 "src/usart.c"
+  ((struct usart *) (0x40004400U))->BRR |= 417;
 
 
   ((struct usart *) (0x40004400U))->CR1 |= (1 << 3);
@@ -2288,8 +2321,8 @@ void usart2_write_byte(uint8_t c) {
   ((struct usart *) (0x40004400U))->DR = c;
 
 
-  while ((((struct usart *) (0x40004400U))->SR & (1 << 7)) == 0);
 
+  while (!(((struct usart *) (0x40004400U))->SR & (1 << 6)));
 }
 
 void usart2_write(char *buf) {
diff --git a/build/usart.o b/build/usart.o
index 6e26695..0ef9ead 100644
Binary files a/build/usart.o and b/build/usart.o differ
diff --git a/src/gpio.h b/src/gpio.h
index 33ef79b..d8edb76 100644
--- a/src/gpio.h
+++ b/src/gpio.h
@@ -21,22 +21,30 @@ struct gpio {
 #define GPIOA ((struct gpio *) GPIOA_BASE_ADDR)
 
 // MODER register
-#define GPIO_MODER_MODER3_BIT 7 // Bits [7:6]
+#define  GPIO_MODER_AF_MODE (0b10)
+
+#define GPIO_MODER_MODER8_BIT 16 // Bits [17:16]
+#define GPIO_MODER_MODER8_MASK (0b11)
+
+#define GPIO_MODER_MODER3_BIT 6 // Bits [7:6]
 #define GPIO_MODER_MODER3_MASK (0b11)
-#define GPIO_MODER_MODER3_AF (0b10)
 
 #define GPIO_MODER_MODER2_BIT 4 // Bits [5:4]
 #define GPIO_MODER_MODER2_MASK (0b11)
-#define GPIO_MODER_MODER2_AF (0b10)
+
+// AFRH register
+#define GPIO_AFRH_AFRH8_BIT 0 // Bits [3:0]
+#define GPIO_AFRH_AFRH8_MASK (0b1111)
+#define GPIO_AFRH_AFRH8_MCO_1 (0b0000) // Alternative function 0 (AF0)
 
 // AFRL register
 #define GPIO_AFRL_AFRL3_BIT 12 // Bits [15:12]
 #define GPIO_AFRL_AFRL3_MASK (0b1111)
-#define GPIO_AFRL_AFRL3_USART2_RX (0b0111) // Alternative function 7
+#define GPIO_AFRL_AFRL3_USART2_RX (0b0111) // Alternative function 7 (AF7)
 
 #define GPIO_AFRL_AFRL2_BIT 8 // Bits [11:8]
 #define GPIO_AFRL_AFRL2_MASK (0b1111)
-#define GPIO_AFRL_AFRL2_USART2_TX (0b0111) // Alternative function 7
+#define GPIO_AFRL_AFRL2_USART2_TX (0b0111) // Alternative function 7 (AF7)
 
 
 
diff --git a/src/main.c b/src/main.c
index 41d2b1b..4cb4592 100644
--- a/src/main.c
+++ b/src/main.c
@@ -18,9 +18,24 @@ static void system_clock_init(void) {
   PWR->CR &= ~(PWR_CR_VOS_MASK << PWR_CR_VOS_BIT);
   PWR->CR |= (PWR_SCALE3 << PWR_CR_VOS_BIT);
 
+  // Turn off HSI (which is on by default)
+  RCC->CR &= ~RCC_CR_HSION_ON;
+
+  // Output HSE clock
+  /* RCC->CFGR &= ~(RCC_CFGR_MCO1_MASK << RCC_CFGR_MCO1_BIT); */
+  /* RCC->CFGR |= (RCC_CFGR_MCO1_HSE << RCC_CFGR_MCO1_BIT); */
+  /* RCC->CFGR |= (RCC_CFGR_MCO1_PLL << RCC_CFGR_MCO1_BIT); */
+  /* RCC->CFGR |= (RCC_CFGR_MCO1_HSI << RCC_CFGR_MCO1_BIT); */
+
+  /* RCC->CFGR &= ~(RCC_CFGR_MCO1PRE_MASK << RCC_CFGR_MCO1PRE_BIT); */
+  /* RCC->CFGR |= (RCC_CFGR_MCO1PRE_DIV4 << RCC_CFGR_MCO1PRE_BIT); */
+
   // Turn on HSE
   RCC->CR |= RCC_CR_HSEON_ON;
 
+  // Turn on clock security system
+  RCC->CR |= RCC_CR_CSS_ON;
+
   // Wait indefinitely for HSE to be ready
   // TODO indicate error/timeout somehow?
   while (!(RCC->CR & RCC_CR_HSERDY_READY));
@@ -30,6 +45,7 @@ static void system_clock_init(void) {
   RCC->CR &= ~RCC_CR_PLLON_ON;
 
   // Set HSE as PLL source
+  /* RCC->PLLCFGR |= RCC_PLLCFGR_PLLSRC_HSE; */
   RCC->PLLCFGR |= RCC_PLLCFGR_PLLSRC_HSE;
 
   // Settings to achieve system clock of 96Mhz
@@ -58,20 +74,17 @@ static void system_clock_init(void) {
   FLASH->ACR |= FLASH_ACR_DCEN_ENABLE;
   FLASH->ACR |= FLASH_ACR_ICEN_ENABLE;
 
+  // TODO breaks with these flash settings on; what were they intended to do?
   // Set latency to be 3 wait states (TODO: understand why exactly 3)
-  FLASH->ACR &= ~(FLASH_ACR_LATENCY_MASK << FLASH_ACR_LATENCY_BIT);
-  RCC->CFGR |= (FLASH_ACR_LATENCY_3_WAIT_STATES << FLASH_ACR_LATENCY_BIT);
+  /* FLASH->ACR &= ~(FLASH_ACR_LATENCY_MASK << FLASH_ACR_LATENCY_BIT); */
+  /* RCC->CFGR |= (FLASH_ACR_LATENCY_3_WAIT_STATES << FLASH_ACR_LATENCY_BIT); */
 
   // Use PLL as system clock
-  RCC->CFGR &= ~(RCC_CFGR_SW_MASK << RCC_CFGR_SW_BIT);
-  RCC->CFGR |= (RCC_CFGR_SW_PLL << RCC_CFGR_SW_BIT);
+  RCC->CFGR |= RCC_CFGR_SW(RCC_CFGR_SW_PLL);
 
   // Wait indefinitely for PLL clock to be selected
   // TODO indicate error/timeout somehow?
   while (((RCC->CFGR >> RCC_CFGR_SWS_BIT) & RCC_CFGR_SWS_MASK) != RCC_CFGR_SWS_PLL);
-
-  // Turn off HSI (which is on by default)
-  RCC->CR &= ~RCC_CR_HSION_ON;
 }
 
 int main(void) {
@@ -93,7 +106,7 @@ int main(void) {
 	 led_on = !led_on;
 	 gpio_write(led, led_on);
 
-	 usart2_write("hello, world\n");
+	 usart2_write("hello, world!\n");
 
 	 counter = TIM4->CNT;
 	}
diff --git a/src/rcc.h b/src/rcc.h
index 045b533..89dfb21 100644
--- a/src/rcc.h
+++ b/src/rcc.h
@@ -46,6 +46,11 @@ struct rcc {
 #define RCC_CR_PLLON_BIT 24
 #define RCC_CR_PLLON_ON  (1 << RCC_CR_PLLON_BIT)
 
+// Clock security system
+#define RCC_CR_CSS_BIT 19
+#define RCC_CR_CSS_ON (1 << RCC_CR_CSS_BIT)
+
+
 // HSE clock ready flag
 #define RCC_CR_HSERDY_BIT 17
 #define RCC_CR_HSERDY_READY (1 << RCC_CR_HSERDY_BIT)
@@ -69,6 +74,7 @@ struct rcc {
 
 #define RCC_PLLCFGR_PLLSRC_BIT 22
 #define RCC_PLLCFGR_PLLSRC_HSE (1 << RCC_PLLCFGR_PLLSRC_BIT)
+#define RCC_PLLCFGR_PLLSRC_HSI (0 << RCC_PLLCFGR_PLLSRC_BIT)
 
 #define RCC_PLLCFGR_PLLP_BIT 16 // Bits [17:16]
 #define RCC_PLLCFGR_PLLP_MASK (0b11)
@@ -87,6 +93,21 @@ struct rcc {
 #define RCC_CFGR_PPRE_DIV_NONE	0
 #define RCC_CFGR_PPRE_DIV_2	(0b100)
 
+// Microcontroller clock output 1
+#define RCC_CFGR_MCO1_HSI (0b00)
+#define RCC_CFGR_MCO1_HSE (0b10)
+#define RCC_CFGR_MCO1_PLL (0b11)
+
+#define RCC_CFGR_MCO1_BIT 21 // Bits [22:21]
+#define RCC_CFGR_MCO1_MASK (0b11)
+
+#define RCC_CFGR_MCO1PRE_DIV5 (0b111)
+#define RCC_CFGR_MCO1PRE_DIV4 (0b110)
+#define RCC_CFGR_MCO1PRE_DIV2 (0b100)
+
+#define RCC_CFGR_MCO1PRE_BIT 24 // Bits [26:24]
+#define RCC_CFGR_MCO1PRE_MASK (0b111)
+
 // APB2
 #define RCC_CFGR_PPRE2_BIT 13 // Bits [15:13]
 #define RCC_CFGR_PPRE2_MASK (0b111)
@@ -109,6 +130,7 @@ struct rcc {
 
 // System clock switch
 #define RCC_CFGR_SW_PLL (0b10)
+#define RCC_CFGR_SW_PLL (0b10)
 
 #define RCC_CFGR_SW_BIT 0 // Bits [1:0]
 #define RCC_CFGR_SW_MASK (0b11)
diff --git a/src/timer.c b/src/timer.c
index 0bec1bd..971b392 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -10,8 +10,8 @@ void tim4_init(void) {
   TIM4->CR2 = 0x0000;
 
   // Set prescaler
-  // f_clk = 48MHz -> /48000 = 1KHz counting frequency = 1ms
-  TIM4->PSC = (uint16_t) 48000 - 1;
+  // f_clk = 96MHz -> 96E6/96E3 = 1E3 = 1KHz counting frequency = 1ms
+  TIM4->PSC = (uint16_t) 96000 - 1;
 
   // Set ARR to maximum value to get 1ms between updates
   TIM4->ARR = (uint16_t) 0xFFFF;
diff --git a/src/usart.c b/src/usart.c
index 32bc316..9ea6c7e 100644
--- a/src/usart.c
+++ b/src/usart.c
@@ -9,9 +9,9 @@ void usart2_init(void) {
   // Configure PA2 and PA3 (USART2 pins) to use alternative functions
   // file:///home/alex/sync/org/stm32-sand/stm32f411ce.pdf#page=48
   GPIOA->MODER &= ~(GPIO_MODER_MODER2_MASK << GPIO_MODER_MODER2_BIT);
-  GPIOA->MODER |= (GPIO_MODER_MODER2_AF << GPIO_MODER_MODER2_BIT);
+  GPIOA->MODER |= (GPIO_MODER_AF_MODE << GPIO_MODER_MODER2_BIT);
   GPIOA->MODER &= ~(GPIO_MODER_MODER3_MASK << GPIO_MODER_MODER3_BIT);
-  GPIOA->MODER |= (GPIO_MODER_MODER3_AF << GPIO_MODER_MODER3_BIT);
+  GPIOA->MODER |= (GPIO_MODER_AF_MODE << GPIO_MODER_MODER3_BIT);
 
   // Set pin alternative modes to use USART
   GPIOA->AFRL &= ~(GPIO_AFRL_AFRL2_MASK << GPIO_AFRL_AFRL2_BIT);
@@ -19,6 +19,14 @@ void usart2_init(void) {
   GPIOA->AFRL &= ~(GPIO_AFRL_AFRL3_MASK << GPIO_AFRL_AFRL3_BIT);
   GPIOA->AFRL |= (GPIO_AFRL_AFRL3_USART2_RX << GPIO_AFRL_AFRL3_BIT);
 
+  // Configure PA8 to output HSE (MCO1)
+  GPIOA->MODER &= ~(GPIO_MODER_MODER8_MASK << GPIO_MODER_MODER8_BIT);
+  GPIOA->MODER |= (GPIO_MODER_AF_MODE << GPIO_MODER_MODER8_BIT);
+
+  // Set pin alternative mode to use MCO1
+  GPIOA->AFRH &= ~(GPIO_AFRH_AFRH8_MASK << GPIO_AFRH_AFRH8_BIT);
+  GPIOA->AFRH |= (GPIO_AFRH_AFRH8_MCO_1 << GPIO_AFRH_AFRH8_BIT);
+
   // Enable USART
   RCC->APB1ENR |= RCC_APB1ENR_USART2EN_ENABLE;
 
@@ -30,33 +38,37 @@ void usart2_init(void) {
   // Calculate Baud rate:
   // baud = f_clck / (8 * (2 - OVER8) * USARTDIV) =>
   // (8 * (2 - OVER8) * USARTDIV) = f_clock / baud =>
+  // baud * (8 * (2 - OVER8) * USARTDIV) = f_clock =>
   // USARTDIV = (f_clock / (baud * (8 * (2 - OVER8)))
 
-  // Target Baud rate = 115200, f_clock = 48MHz
+  // Target Baud rate = 115200, f_clock = 48MHz,OVER8 = 0
 
-  // With OVER8 = 1 (oversampling by 8)
-  // USARTDIV = (48E6 / (115200 * (8 * (2 - 0)))) = 26.0416666
-  // mantissa = 26
-  // fraction = 0.041666 * 8 = 0.33328 ~= 0
+  // USARTDIV = (48E6 / (115200 * (8 * 2))) = 26.0416666
+  // mantissa = 26 = 0x1A
+  // fraction = 0.041666 * 16 = 0.666656 ~= 1
 
-  // rounding fraction up: USARTDIV = 26
   // baud = 48E6 / (8 * 2 * 26) = 115384.61538461539
   // error of 0.001% (115384.61538461539 / 115200 ) = 1.001602564102564
 
+  // f_clock = USARTDIV * (baud * (8 * 2)
+  // f_clock = 26 * 115200 * 16 = 47923200 = 48MHz
 
-  // baud = f_clck / (8 * (2 - OVER8) * USARTDIV) */
-  // baud * ((8 * (2 - OVER8) * USARTDIV)) = f_clck */
-  // 393400 * (8 * 2 * 26) = 163654400
+  // fclk = 13 * 115200 * 16
+
+
+  // Baud = 9600
+  // USARTDIV = (48E6 / (9600 * (8 * 2))) = 312.5
+  // mantissa = 312 = 0x138
+  // fraction = 0.5 * 16 = 8 = 0x8
+  // BRR = 0x1388
 
 
   /* USART2->CR1 |= USART_CR1_OVER8_8; */
 
-  USART2->BRR &= ~(USART_BRR_MANTISSA_MASK << USART_BRR_MANTISSA_BIT);
-  USART2->BRR |= (0x34 << USART_BRR_MANTISSA_BIT);
-  /* USART2->BRR |= (0x69 << USART_BRR_MANTISSA_BIT); */
+  /* USART2->BRR &= ~(USART_BRR_MANTISSA_MASK << USART_BRR_MANTISSA_BIT); */
   /* USART2->BRR |= (0x1A << USART_BRR_MANTISSA_BIT); */
-  USART2->BRR &= ~(USART_BRR_FRACTION_MASK << USART_BRR_FRACTION_BIT);
-  USART2->BRR |= (0x0 << USART_BRR_FRACTION_BIT);
+  /* USART2->BRR &= ~(USART_BRR_FRACTION_MASK << USART_BRR_FRACTION_BIT); */
+  USART2->BRR |= 417;
 
   // Enable transmitter and receiver
   USART2->CR1 |= USART_CR1_TE_ENABLE;
@@ -72,8 +84,8 @@ void usart2_write_byte(uint8_t c) {
   USART2->DR = c;
 
   // Wait indefinitely for transmission to be ready for data
-  while ((USART2->SR & USART_SR_TXE_TRANSMITTED) == 0);
-  /* while (!(USART2->SR & USART_SR_TC_COMPLETED)); */
+  /* while ((USART2->SR & USART_SR_TXE_TRANSMITTED) == 0); */
+  while (!(USART2->SR & USART_SR_TC_COMPLETED));
 }
 
 void usart2_write(char *buf) {
diff --git a/src/usart.h b/src/usart.h
index c44a0ad..48a121d 100644
--- a/src/usart.h
+++ b/src/usart.h
@@ -49,10 +49,10 @@ struct usart {
 
 // BRR Register
 #define USART_BRR_MANTISSA_BIT 4 // Bits [15:4]
-#define USART_BRR_MANTISSA_MASK (0b111111111111) // Bits [15:4]
+#define USART_BRR_MANTISSA_MASK (0b111111111111)
 
 #define USART_BRR_FRACTION_BIT 0 // Bits [3:0]
-#define USART_BRR_FRACTION_MASK (0b111) // Bits [3:0]
+#define USART_BRR_FRACTION_MASK (0b111)
 
 void usart2_init(void);
 void usart2_start(void);