From 3aad7271a18286f069d7089639c966c7e0674c77 Mon Sep 17 00:00:00 2001
From: Alexander Heldt <me@alexanderheldt.se>
Date: Mon, 30 Dec 2024 11:48:38 +0100
Subject: [PATCH] Use `RCC_CFGR_SW` helper function to set software clock

---
 build/final.elf     | Bin 55108 -> 55088 bytes
 build/final.elf.map | 204 ++++++++++++++++++++++----------------------
 build/main.S        |  73 +++++++---------
 build/main.i        |  11 ++-
 build/main.o        | Bin 48592 -> 48576 bytes
 src/main.c          |   3 +-
 6 files changed, 141 insertions(+), 150 deletions(-)

diff --git a/build/final.elf b/build/final.elf
index e6ae9b9d07bbea34512c92474c3b43c177b02eac..364d3f75554307ee5409e2fa3d5859e17ffd3deb 100755
GIT binary patch
delta 2450
zcmX@Ij(Nj6<_Qv<xhxDECJYP=784bfS)Z^lFg)4lxtm`UBwWkFz=47%D+&tN!$cSu
z7#Lt|I@0y1PC|Dg4f!AsGcat{5>#TW_wbg^arbim&=4$~;^r-#;p(OQ#lcxP!P#3n
z!^z7T%(nNI&am@R{=mpAoM7WEonh_e{H4KIIDuimrMGkj^A`qV2JN30%)F&DOudvp
zG!zRb7<)%&7=ctV2PYVKM`h@H8h8skdnf36&(6^CQvUFPd2)i5x2D(Z`i#j58s4)r
z)V-9yJP4kgpz1w4Lj|NUcyfZ0_v{QsFXb-@&XW`5z2&@SXG~6z^_I?%0XerAWW6NF
z`VS1nAnQSF36RcY;RG>n=?qaX=PwM!!U@9O(iuWt${+Zdg%fzaXJ_zuIe+OWcK*P~
zJUM~Wdvcht9b^3Dslxh<?<XG>wq;`cKbb`&h4IPeOp!TkzTT`=3=9kn%nTeI3=9m6
zbF5hy7=&|DQy3Tnc|ame6N`90L@+RfLV0C8jIj(1VeDs_85o!*mNJOchchrR^6+{v
zF>qK+4wBYjd^NdRdb4T`3j+rS*hGQuI0gnrQMMcw1`YwRh@c)wgpG}3a<GgmBj4ni
zGMbDAlMl<-GhW%uEc=~F@CXY7hXPnBn{q4z153+hZiR^~tQL$63=NYPs>lm+urP3>
zFfcH{%&eJwQAM7!g@u8`fq{YH$mE|YmbN>X*umanWRPZHU|?ln0VfJ}uvT`kMs|oJ
zMUkb!X0RXGoUdB1%=l{adyf^|OjnpUfACntwb?cPDHG#`&Du$^jFbD4wb?+%GoPBg
zKY2SN$K>)9cgCE_`%|PDYbM`LS<BcmxieLt@yO<#sRt7$*Bq~r1-aglkENZ_k(ZsR
zpO@F^I3I%y0|P?>DEudjp3rCHnCyB&oiS%}?g@|~ohQ^8TPANjA<uYZ^TiX|jD{eW
zgZ;q3#K6bEz!1U0019CS1_mYuZfIb@<U#zJ$-1YCbwSoLL3I=`qv`;80Hy<EBE#gf
zr{wEFL4Yi}2hAQ(>>$fOK$5qFmNX!TDKRiH*rV}%(fEOA{9pzKCvZ^(Gav#@0Vvj=
zKrIwt`1n5`O}-YypS<?8ykRXg1%jM0i-CawR7`@>pAZ8R!vc^hB>ANv{^Y-><pq&-
z9S4i*o{<L^q%arV1&Jc*eTBw<kH-Il#0S~U!w4yiVdjaT@#WF@YK#n%PoGgl@sBH-
z8Xq)%2#7yf_AIK)a~T;JTA_Ia<dSlbDkPs&Gcqu6LUR^Kz8y_|A{u`h8h;KNe>o!q
z6GQFfy=cxjji&4d8vg+r|0x>(4I2L^8lR1cfuRvvpn<%>&BRcTlBNWiP-8#_jjw{n
z*G1!7q4Dj|_)chi4<=z$3;jR}Cciz08a?G8QKaZ-MdSCP@n<qIFdT)JlpudDL6cvJ
z#@~j<--jM97ts{lMB_h0<9|lu|3>3;Fr#`~6pb&*Y>cWv5lw*_8ebd4-)wuKn1#`2
z^2RI5Oix56|GOeK`OOsz#wU|iuc|Y0PWHX3&Kjb^z_4O6<5l6wJy!*o{-{izcU6rs
zWAf3f>Z}}z3=Eqmf4r*9xO=kbHFd`P$+p+jS+^WvU@!q|sJSM<_+oPJHFd^}$y=|f
aGhUf|_nJDR$z;~+>a01J85mB3Q~>~DY@YQ1

delta 2440
zcmdn6j`_$s<_Qv<l`IS#CJYP=J`)v{SwFBaFnrkPxtm`UB;3iuz=47%D+&tN!$cSu
z7#Lt|I@0y1PC|Dg4f!AsGcat{5>#TW_x6^~@$z#1&=4$~;^{4&;o+tH#lcxP!OdGb
z!_~_f%y#mY&T#Zn{=mpAoM7)QonhzY{H4KIIDuimjkk0L^A`qV2JN30EWM>OEWDII
zG!zRbn0ZHMn1WO>2PYVNM`aj!8hZ;ndnXup&(6^IQvUFPd2)iTw~p8B`i#j5+TOD>
zw7itRJP4kgpy53`Lmi|scyfZO_v{Q6FXb-@&XW_AycNA>XG~5|@RrVy2RXMGWW5Z?
z`VS1nAnQSFX^_rj;RH!<=?n=k=PwM!!U<yD(ix&&${+Zdg%bq4XJ_zxIe+OWcK*P~
zJUM~Kn|*c$x0mt<=E<(Y&Ww?hJB9TbUrydBY|Hff-{c>{DU2UB$BN8hGxuSwVqjqC
zVP@dyU|?WioMX+xz#yEHn!>;s!~+sxnpnj1A%cM+49Y9xVT@&92%l^qEz0OJ*-cu5
z@x$bN>CLJgEDRhRU=swo;}{qiMcFD?7&rvLB7%A#5jHlF$?h_)j8c<(Wi%OWCU2Lq
zXS}ufyUcec!3!)59138iY|60=3@j5i|CgW0!s^1vz|b>!s*1dz2nz#83IhWJ%*>9-
zM^)rGC$KPZI503UT$ub;#nSc&6Fb-&j11BY3=FIcEa1ez4%W&J*2oTVq$sj9*bMdy
zo0C=Rm6<*;ZSD<O!!>zA@NdRjn|neg@iJc9ET0t1$fRgHxguGg4P*iH>B(!8w=;@N
zPEB!VteCtuMVhf=^2wC7j1wl8r|L6a*t|UTU?L;K<n-gUvLGKg^0BltI`XnJP37fv
zI?l%+!@$6h01ETTj3@LNMJ5}bP-m=|9C-p{Oz8=A#tD<>o{(p}uzBwZZAL?o>%snD
zU}E57U|>jLVE~0P0|NsS12;54VDcb-$7IP<#kwGCnV>pqm{E0rya3YyGLdKU&QtRB
zpkP22J%MHqD29;b-yq3bLQ5Ht!;~1980^vbzG(bFG=4AxgA=%zf*BBjrT`T4AD|Wr
zFns)<k0xIW;!mD=THX*;$iYmR#lXM-Dk4E?P>6wvVF5@LG?jv!xfH~o{PMKCAhNFG
zU{T34^58-gX4YMhD3ab+X#DqR{69#1klj3tkb)Ryo(LLW9*wWY$S`^P8ATNTxT2}?
zLF0#j_>(!$qPjenk%3_%G@pQ6QVvpu<dbSf1_n`R?gGiTqsdQ1<4;55&q3oaXJlYv
z=$yO~%^9cBl-)q%KS1L@MdQCg<NrkCvoSF+^g;_UkT<xQ80t~dlpqso49KAIRnYjl
zXnZR)z8xCh361Z;B#dgIA4tLEo99rYryL}T6dkQ-{9ZKvOeO|~i_p>%<j*B&@+;B!
z+tB#?(8J{-nu42X{AXzV&uIMLXnYQ4RBwx-@g<p!Q57hnDNsY>YlHZkH7^viFh)$C
zdqtV?!{mck{24z?7QCv?C_35lsybuB<ixA$OdP6{yRND+mQ3DwRh?BNk%3|7<hxgu
z8P85;yr$0BI9c<WI^(g)f!EX-e@(8urp{P1dEqs6#ut-MUQ=iEnEdgYx<tce28Pp+
MLJmwaf=LDj0ErKw4FCWD

diff --git a/build/final.elf.map b/build/final.elf.map
index d9b7e68..006e196 100644
--- a/build/final.elf.map
+++ b/build/final.elf.map
@@ -121,7 +121,7 @@ LOAD build/timer.o
                 0x08000000                interrupt_vector_table
                 0x08000198                        . = ALIGN (0x4)
 
-.text           0x08000198      0x358
+.text           0x08000198      0x34c
                 0x08000198                        . = ALIGN (0x4)
  *(.text)
  *(.text.*)
@@ -133,114 +133,114 @@ LOAD build/timer.o
                 0x080001fa                gpio_write
  *fill*         0x08000246        0x2 
  .text.system_clock_init
-                0x08000248      0x144 build/main.o
- .text.main     0x0800038c       0x88 build/main.o
-                0x0800038c                main
+                0x08000248      0x138 build/main.o
+ .text.main     0x08000380       0x88 build/main.o
+                0x08000380                main
  .text.init_memory
-                0x08000414       0x64 build/startup.o
-                0x08000414                init_memory
- .text.reset    0x08000478       0x10 build/startup.o
-                0x08000478                reset
+                0x08000408       0x64 build/startup.o
+                0x08000408                init_memory
+ .text.reset    0x0800046c       0x10 build/startup.o
+                0x0800046c                reset
  .text.default_handler
-                0x08000488        0x8 build/startup.o
-                0x08000488                exti0
-                0x08000488                debug_monitor
-                0x08000488                rcc
-                0x08000488                x
-                0x08000488                sdio
-                0x08000488                usage_fault
-                0x08000488                tim1_up_tim10
-                0x08000488                usart1
-                0x08000488                i2c3_er
-                0x08000488                spi2
-                0x08000488                dma1_stream1
-                0x08000488                bus_fault
-                0x08000488                spi5
-                0x08000488                exti3
-                0x08000488                dma2_stream5
-                0x08000488                tim2
-                0x08000488                dma1_stream6
-                0x08000488                default_handler
-                0x08000488                i2c1_er
-                0x08000488                hard_fault
-                0x08000488                usart6
-                0x08000488                exti15_10
-                0x08000488                usart2
-                0x08000488                pend_sv
-                0x08000488                i2c1_ev
-                0x08000488                wwdg
-                0x08000488                adc
-                0x08000488                rtc_alarm
-                0x08000488                spi3
-                0x08000488                exti1
-                0x08000488                mem_manage
-                0x08000488                dma2_stream1
-                0x08000488                dma1_stream2
-                0x08000488                dma2_stream3
-                0x08000488                sv_call
-                0x08000488                tim3
-                0x08000488                otg_fs
-                0x08000488                dma1_stream5
-                0x08000488                dma2_stream6
-                0x08000488                flash
-                0x08000488                tamp_stamp
-                0x08000488                i2c3_ev
-                0x08000488                rtc_wkup
-                0x08000488                dma2_stream0
-                0x08000488                pvd
-                0x08000488                fpu
-                0x08000488                exti4
-                0x08000488                exti2
-                0x08000488                spi1
-                0x08000488                dma1_stream0
-                0x08000488                tim1_brk_tim9
-                0x08000488                i2c2_ev
-                0x08000488                otg_fs_wkup
-                0x08000488                spi4
-                0x08000488                dma2_stream2
-                0x08000488                tim1_cc
-                0x08000488                tim1_trg_com_tim11
-                0x08000488                exti9_5
-                0x08000488                dma1_stream3
-                0x08000488                dma2_stream4
-                0x08000488                i2c2_er
-                0x08000488                dma2_stream7
-                0x08000488                dma1_stream7
-                0x08000488                nmi
-                0x08000488                systick
-                0x08000488                tim4
-                0x08000488                tim5
-                0x08000488                dma1_stream4
+                0x0800047c        0x8 build/startup.o
+                0x0800047c                exti0
+                0x0800047c                debug_monitor
+                0x0800047c                rcc
+                0x0800047c                x
+                0x0800047c                sdio
+                0x0800047c                usage_fault
+                0x0800047c                tim1_up_tim10
+                0x0800047c                usart1
+                0x0800047c                i2c3_er
+                0x0800047c                spi2
+                0x0800047c                dma1_stream1
+                0x0800047c                bus_fault
+                0x0800047c                spi5
+                0x0800047c                exti3
+                0x0800047c                dma2_stream5
+                0x0800047c                tim2
+                0x0800047c                dma1_stream6
+                0x0800047c                default_handler
+                0x0800047c                i2c1_er
+                0x0800047c                hard_fault
+                0x0800047c                usart6
+                0x0800047c                exti15_10
+                0x0800047c                usart2
+                0x0800047c                pend_sv
+                0x0800047c                i2c1_ev
+                0x0800047c                wwdg
+                0x0800047c                adc
+                0x0800047c                rtc_alarm
+                0x0800047c                spi3
+                0x0800047c                exti1
+                0x0800047c                mem_manage
+                0x0800047c                dma2_stream1
+                0x0800047c                dma1_stream2
+                0x0800047c                dma2_stream3
+                0x0800047c                sv_call
+                0x0800047c                tim3
+                0x0800047c                otg_fs
+                0x0800047c                dma1_stream5
+                0x0800047c                dma2_stream6
+                0x0800047c                flash
+                0x0800047c                tamp_stamp
+                0x0800047c                i2c3_ev
+                0x0800047c                rtc_wkup
+                0x0800047c                dma2_stream0
+                0x0800047c                pvd
+                0x0800047c                fpu
+                0x0800047c                exti4
+                0x0800047c                exti2
+                0x0800047c                spi1
+                0x0800047c                dma1_stream0
+                0x0800047c                tim1_brk_tim9
+                0x0800047c                i2c2_ev
+                0x0800047c                otg_fs_wkup
+                0x0800047c                spi4
+                0x0800047c                dma2_stream2
+                0x0800047c                tim1_cc
+                0x0800047c                tim1_trg_com_tim11
+                0x0800047c                exti9_5
+                0x0800047c                dma1_stream3
+                0x0800047c                dma2_stream4
+                0x0800047c                i2c2_er
+                0x0800047c                dma2_stream7
+                0x0800047c                dma1_stream7
+                0x0800047c                nmi
+                0x0800047c                systick
+                0x0800047c                tim4
+                0x0800047c                tim5
+                0x0800047c                dma1_stream4
  .text.tim4_init
-                0x08000490       0x40 build/timer.o
-                0x08000490                tim4_init
+                0x08000484       0x40 build/timer.o
+                0x08000484                tim4_init
  .text.tim4_start
-                0x080004d0       0x20 build/timer.o
-                0x080004d0                tim4_start
+                0x080004c4       0x20 build/timer.o
+                0x080004c4                tim4_start
  *(.rodata)
  *(.rodata.*)
-                0x080004f0                        . = ALIGN (0x4)
-                0x080004f0                        _data_addr = LOADADDR (.data)
+                0x080004e4                        . = ALIGN (0x4)
+                0x080004e4                        _data_addr = LOADADDR (.data)
 
-.glue_7         0x080004f0        0x0
- .glue_7        0x080004f0        0x0 linker stubs
+.glue_7         0x080004e4        0x0
+ .glue_7        0x080004e4        0x0 linker stubs
 
-.glue_7t        0x080004f0        0x0
- .glue_7t       0x080004f0        0x0 linker stubs
+.glue_7t        0x080004e4        0x0
+ .glue_7t       0x080004e4        0x0 linker stubs
 
-.vfp11_veneer   0x080004f0        0x0
- .vfp11_veneer  0x080004f0        0x0 linker stubs
+.vfp11_veneer   0x080004e4        0x0
+ .vfp11_veneer  0x080004e4        0x0 linker stubs
 
-.v4_bx          0x080004f0        0x0
- .v4_bx         0x080004f0        0x0 linker stubs
+.v4_bx          0x080004e4        0x0
+ .v4_bx         0x080004e4        0x0 linker stubs
 
-.iplt           0x080004f0        0x0
- .iplt          0x080004f0        0x0 build/main.o
+.iplt           0x080004e4        0x0
+ .iplt          0x080004e4        0x0 build/main.o
 
-.rel.dyn        0x080004f0        0x0
- .rel.iplt      0x080004f0        0x0 build/main.o
+.rel.dyn        0x080004e4        0x0
+ .rel.iplt      0x080004e4        0x0 build/main.o
 
-.data           0x20000000        0x0 load address 0x080004f0
+.data           0x20000000        0x0 load address 0x080004e4
                 0x20000000                        . = ALIGN (0x4)
                 0x20000000                        _data_start = .
  *(.data)
@@ -248,10 +248,10 @@ LOAD build/timer.o
                 0x20000000                        . = ALIGN (0x4)
                 0x20000000                        _data_end = .
 
-.igot.plt       0x20000000        0x0 load address 0x080004f0
+.igot.plt       0x20000000        0x0 load address 0x080004e4
  .igot.plt      0x20000000        0x0 build/main.o
 
-.bss            0x20000000        0x0 load address 0x080004f0
+.bss            0x20000000        0x0 load address 0x080004e4
                 0x20000000                        . = ALIGN (0x4)
                 0x20000000                        _bss_start = .
  *(.bss)
@@ -321,11 +321,11 @@ LOAD linker stubs
  .debug_macro   0x00002f20      0xb5c build/timer.o
  .debug_macro   0x00003a7c      0x124 build/timer.o
 
-.debug_line     0x00000000      0x4b9
+.debug_line     0x00000000      0x4b3
  .debug_line    0x00000000      0x116 build/gpio.o
- .debug_line    0x00000116      0x1da build/main.o
- .debug_line    0x000002f0       0xea build/startup.o
- .debug_line    0x000003da       0xdf build/timer.o
+ .debug_line    0x00000116      0x1d4 build/main.o
+ .debug_line    0x000002ea       0xea build/startup.o
+ .debug_line    0x000003d4       0xdf build/timer.o
 
 .debug_str      0x00000000     0x5eb4
  .debug_str     0x00000000     0x536f build/gpio.o
diff --git a/build/main.S b/build/main.S
index 7b4b13b..323a419 100644
--- a/build/main.S
+++ b/build/main.S
@@ -195,29 +195,22 @@ system_clock_init:
 	ldr	r3, [r3, #8]
 	ldr	r2, .L5
 	.loc 1 68 40
-	bic	r3, r3, #3
-	str	r3, [r2, #8]
-	.loc 1 69 33
-	ldr	r3, .L5
-	ldr	r3, [r3, #8]
-	ldr	r2, .L5
-	.loc 1 69 40
 	orr	r3, r3, #2
 	str	r3, [r2, #8]
-	.loc 1 73 9
+	.loc 1 72 9
 	nop
 .L4:
-	.loc 1 73 42 discriminator 1
+	.loc 1 72 42 discriminator 1
 	ldr	r3, .L5
 	ldr	r3, [r3, #8]
-	.loc 1 73 49 discriminator 1
+	.loc 1 72 49 discriminator 1
 	lsrs	r3, r3, #2
-	.loc 1 73 55 discriminator 1
+	.loc 1 72 55 discriminator 1
 	and	r3, r3, #3
-	.loc 1 73 65 discriminator 1
+	.loc 1 72 65 discriminator 1
 	cmp	r3, #2
 	bne	.L4
-	.loc 1 74 1
+	.loc 1 73 1
 	nop
 	nop
 	mov	sp, r7
@@ -246,7 +239,7 @@ system_clock_init:
 	.type	main, %function
 main:
 .LFB1:
-	.loc 1 76 16
+	.loc 1 75 16
 	.cfi_startproc
 	@ args = 0, pretend = 0, frame = 8
 	@ frame_needed = 1, uses_anonymous_args = 0
@@ -258,56 +251,56 @@ main:
 	.cfi_def_cfa_offset 16
 	add	r7, sp, #0
 	.cfi_def_cfa_register 7
-	.loc 1 77 3
+	.loc 1 76 3
 	bl	system_clock_init
-	.loc 1 78 3
+	.loc 1 77 3
 	bl	tim4_init
-	.loc 1 80 3
+	.loc 1 79 3
 	bl	tim4_start
-	.loc 1 82 12
+	.loc 1 81 12
 	movw	r3, #525
 	strh	r3, [r7, #2]	@ movhi
-	.loc 1 83 33
+	.loc 1 82 33
 	ldr	r3, .L10
 	ldr	r3, [r3, #48]
-	.loc 1 83 57
+	.loc 1 82 57
 	ldrh	r2, [r7, #2]
 	lsrs	r2, r2, #8
 	uxth	r2, r2
 	mov	r1, r2
-	.loc 1 83 49
+	.loc 1 82 49
 	movs	r2, #1
 	lsls	r2, r2, r1
 	mov	r1, r2
-	.loc 1 83 33
+	.loc 1 82 33
 	ldr	r2, .L10
-	.loc 1 83 43
+	.loc 1 82 43
 	orrs	r3, r3, r1
 	str	r3, [r2, #48]
-	.loc 1 84 3
+	.loc 1 83 3
 	ldrh	r3, [r7, #2]
 	movs	r1, #1
 	mov	r0, r3
 	bl	gpio_set_mode
-	.loc 1 86 54
+	.loc 1 85 54
 	ldr	r3, .L10+4
 	ldr	r3, [r3, #36]
-	.loc 1 86 12
+	.loc 1 85 12
 	strh	r3, [r7, #6]	@ movhi
-	.loc 1 87 7
+	.loc 1 86 7
 	movs	r3, #0
 	strb	r3, [r7, #5]
 .L9:
-	.loc 1 89 39
+	.loc 1 88 39
 	ldr	r3, .L10+4
 	ldr	r2, [r3, #36]
-	.loc 1 89 45
+	.loc 1 88 45
 	ldrh	r3, [r7, #6]
 	subs	r3, r2, r3
-	.loc 1 89 5
+	.loc 1 88 5
 	cmp	r3, #249
 	bls	.L9
-	.loc 1 90 3
+	.loc 1 89 3
 	ldrb	r3, [r7, #5]	@ zero_extendqisi2
 	cmp	r3, #0
 	ite	ne
@@ -316,23 +309,23 @@ main:
 	uxtb	r3, r3
 	eor	r3, r3, #1
 	uxtb	r3, r3
-	.loc 1 90 10
+	.loc 1 89 10
 	strb	r3, [r7, #5]
 	ldrb	r3, [r7, #5]
 	and	r3, r3, #1
 	strb	r3, [r7, #5]
-	.loc 1 91 3
+	.loc 1 90 3
 	ldrb	r2, [r7, #5]	@ zero_extendqisi2
 	ldrh	r3, [r7, #2]
 	mov	r1, r2
 	mov	r0, r3
 	bl	gpio_write
-	.loc 1 93 45
+	.loc 1 92 45
 	ldr	r3, .L10+4
 	ldr	r3, [r3, #36]
-	.loc 1 93 11
+	.loc 1 92 11
 	strh	r3, [r7, #6]	@ movhi
-	.loc 1 89 5
+	.loc 1 88 5
 	b	.L9
 .L11:
 	.align	2
@@ -860,7 +853,7 @@ main:
 	.uleb128 0x12
 	.4byte	.LASF1005
 	.byte	0x1
-	.byte	0x4c
+	.byte	0x4b
 	.byte	0x5
 	.4byte	0x7a
 	.4byte	.LFB1
@@ -871,7 +864,7 @@ main:
 	.uleb128 0x13
 	.ascii	"led\000"
 	.byte	0x1
-	.byte	0x52
+	.byte	0x51
 	.byte	0xc
 	.4byte	0x88
 	.uleb128 0x2
@@ -879,7 +872,7 @@ main:
 	.sleb128 -14
 	.uleb128 0xc
 	.4byte	.LASF1000
-	.byte	0x56
+	.byte	0x55
 	.byte	0xc
 	.4byte	0x88
 	.uleb128 0x2
@@ -887,7 +880,7 @@ main:
 	.sleb128 -10
 	.uleb128 0xc
 	.4byte	.LASF1001
-	.byte	0x57
+	.byte	0x56
 	.byte	0x7
 	.4byte	0x3cd
 	.uleb128 0x2
diff --git a/build/main.i b/build/main.i
index d6cb1ed..dfd3ab9 100644
--- a/build/main.i
+++ b/build/main.i
@@ -2302,8 +2302,7 @@ static void system_clock_init(void) {
   ((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);
 
 
 
@@ -2322,13 +2321,13 @@ int main(void) {
 
   uint16_t counter = ((struct timer *) (0x40000800U))->CNT;
   
-# 87 "src/main.c" 3 4
+# 86 "src/main.c" 3 4
  _Bool 
-# 87 "src/main.c"
+# 86 "src/main.c"
       led_on = 
-# 87 "src/main.c" 3 4
+# 86 "src/main.c" 3 4
                ((_Bool)+0u)
-# 87 "src/main.c"
+# 86 "src/main.c"
                     ;
   while(1) {
  if ((((struct timer *) (0x40000800U))->CNT - counter) >= 250) {
diff --git a/build/main.o b/build/main.o
index a62cebb4b1caa0599d56accb964ef6f3d85993ea..e3ccc40ad397b8def0206d30f3931f0517f28c48 100644
GIT binary patch
delta 904
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LjG&|e!7wHO=d2ik

delta 908
zcmX@`o9V)DrU?p+8WR=Y*L!<Q=XiNJe`p96PVw}X&hYS3{^H;)oZ#jyo#E=`3}!od
zOJ_KGDSu#O7EZADmd>#Aa{kg_ES$iw-^N=ygZT@CF@yHc3zpu}85Um39~z2<6U@A$
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zz+eK_%(z>f)k1-R!EN&29V(LpcdN73DKIeTf$iNfdEst#rZoy+lRixTxLcj|oB{*G
zt;w=`lo=%^JMK|uTroLwk2<5m<cWLK8Pg{3+ye^fhkMkS7&c7i+N;KBFxhagI%CS@
a$i3=}Et4Dfs!J$rU|?Wn1SJayhA{ycbR0(j

diff --git a/src/main.c b/src/main.c
index 8129bf2..2479373 100644
--- a/src/main.c
+++ b/src/main.c
@@ -65,8 +65,7 @@ static void system_clock_init(void) {
   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?