diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5fae1b3
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.direnv/
+.ccls-cache/
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..91d2608
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,43 @@
+CC = arm-none-eabi-gcc
+
+CFLAGS = -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16
+CFLAGS += -Wall -Werror -Wpedantic -Wextra
+# Remove unused code and data; https://gcc.gnu.org/onlinedocs/gnat_ugn/Compilation-options.html
+CFLAGS += -ffunction-sections -fdata-sections
+# Don't include memcpy
+CFLAGS += -fno-builtin
+# "-fno-common ... specifies that the compiler places uninitialized global variables in the BSS section of the object file."
+CFLAGS += -fno-common
+
+DEBUG ?= 1
+ifeq ($(DEBUG), 0)
+	# Optimize for size
+	CFLAGS += -Os
+else
+	CFLAGS += -O0 -g3 -ggdb
+endif
+
+LDFLAGS = -T link.ld -nostartfiles -nostdlib --specs nano.specs -lc -lgcc -Wl,--gc-sections -Wl,-Map=$@.map
+
+SRC_DIR = src
+BUILD_DIR = build
+
+SRC_FILES := $(wildcard $(SRC_DIR)/*.c)
+PREP_FILES := $(patsubst $(SRC_DIR)/%.c,$(BUILD_DIR)/%.i,$(SRC_FILES))
+
+.PHONY: build
+build: builddir preprocess
+
+$(BUILD_DIR)/%.i: $(SRC_DIR)/%.c
+	$(CC) $(CFLAGS) -E $^ -o $@
+
+.PHONY: builddir
+builddir:
+	mkdir $(BUILD_DIR)
+
+.PHONY: preprocess
+preprocess: $(PREP_FILES)
+
+.PHONY: clean
+clean:
+	rm -rf $(BUILD_DIR)
diff --git a/build/main.i b/build/main.i
new file mode 100644
index 0000000..672bc7d
--- /dev/null
+++ b/build/main.i
@@ -0,0 +1,912 @@
+# 0 "src/main.c"
+# 1 "/home/alex/code/own/c-compile-experiments//"
+# 0 "<built-in>"
+#define __STDC__ 1
+# 0 "<built-in>"
+#define __STDC_VERSION__ 201710L
+# 0 "<built-in>"
+#define __STDC_UTF_16__ 1
+# 0 "<built-in>"
+#define __STDC_UTF_32__ 1
+# 0 "<built-in>"
+#define __STDC_HOSTED__ 1
+# 0 "<built-in>"
+#define __GNUC__ 12
+# 0 "<built-in>"
+#define __GNUC_MINOR__ 3
+# 0 "<built-in>"
+#define __GNUC_PATCHLEVEL__ 1
+# 0 "<built-in>"
+#define __VERSION__ "12.3.1 20230626"
+# 0 "<built-in>"
+#define __ATOMIC_RELAXED 0
+# 0 "<built-in>"
+#define __ATOMIC_SEQ_CST 5
+# 0 "<built-in>"
+#define __ATOMIC_ACQUIRE 2
+# 0 "<built-in>"
+#define __ATOMIC_RELEASE 3
+# 0 "<built-in>"
+#define __ATOMIC_ACQ_REL 4
+# 0 "<built-in>"
+#define __ATOMIC_CONSUME 1
+# 0 "<built-in>"
+#define __FINITE_MATH_ONLY__ 0
+# 0 "<built-in>"
+#define __SIZEOF_INT__ 4
+# 0 "<built-in>"
+#define __SIZEOF_LONG__ 4
+# 0 "<built-in>"
+#define __SIZEOF_LONG_LONG__ 8
+# 0 "<built-in>"
+#define __SIZEOF_SHORT__ 2
+# 0 "<built-in>"
+#define __SIZEOF_FLOAT__ 4
+# 0 "<built-in>"
+#define __SIZEOF_DOUBLE__ 8
+# 0 "<built-in>"
+#define __SIZEOF_LONG_DOUBLE__ 8
+# 0 "<built-in>"
+#define __SIZEOF_SIZE_T__ 4
+# 0 "<built-in>"
+#define __CHAR_BIT__ 8
+# 0 "<built-in>"
+#define __BIGGEST_ALIGNMENT__ 8
+# 0 "<built-in>"
+#define __ORDER_LITTLE_ENDIAN__ 1234
+# 0 "<built-in>"
+#define __ORDER_BIG_ENDIAN__ 4321
+# 0 "<built-in>"
+#define __ORDER_PDP_ENDIAN__ 3412
+# 0 "<built-in>"
+#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
+# 0 "<built-in>"
+#define __FLOAT_WORD_ORDER__ __ORDER_LITTLE_ENDIAN__
+# 0 "<built-in>"
+#define __SIZEOF_POINTER__ 4
+# 0 "<built-in>"
+#define __GNUC_EXECUTION_CHARSET_NAME "UTF-8"
+# 0 "<built-in>"
+#define __GNUC_WIDE_EXECUTION_CHARSET_NAME "UTF-32LE"
+# 0 "<built-in>"
+#define __SIZE_TYPE__ unsigned int
+# 0 "<built-in>"
+#define __PTRDIFF_TYPE__ int
+# 0 "<built-in>"
+#define __WCHAR_TYPE__ unsigned int
+# 0 "<built-in>"
+#define __WINT_TYPE__ unsigned int
+# 0 "<built-in>"
+#define __INTMAX_TYPE__ long long int
+# 0 "<built-in>"
+#define __UINTMAX_TYPE__ long long unsigned int
+# 0 "<built-in>"
+#define __CHAR16_TYPE__ short unsigned int
+# 0 "<built-in>"
+#define __CHAR32_TYPE__ long unsigned int
+# 0 "<built-in>"
+#define __SIG_ATOMIC_TYPE__ int
+# 0 "<built-in>"
+#define __INT8_TYPE__ signed char
+# 0 "<built-in>"
+#define __INT16_TYPE__ short int
+# 0 "<built-in>"
+#define __INT32_TYPE__ long int
+# 0 "<built-in>"
+#define __INT64_TYPE__ long long int
+# 0 "<built-in>"
+#define __UINT8_TYPE__ unsigned char
+# 0 "<built-in>"
+#define __UINT16_TYPE__ short unsigned int
+# 0 "<built-in>"
+#define __UINT32_TYPE__ long unsigned int
+# 0 "<built-in>"
+#define __UINT64_TYPE__ long long unsigned int
+# 0 "<built-in>"
+#define __INT_LEAST8_TYPE__ signed char
+# 0 "<built-in>"
+#define __INT_LEAST16_TYPE__ short int
+# 0 "<built-in>"
+#define __INT_LEAST32_TYPE__ long int
+# 0 "<built-in>"
+#define __INT_LEAST64_TYPE__ long long int
+# 0 "<built-in>"
+#define __UINT_LEAST8_TYPE__ unsigned char
+# 0 "<built-in>"
+#define __UINT_LEAST16_TYPE__ short unsigned int
+# 0 "<built-in>"
+#define __UINT_LEAST32_TYPE__ long unsigned int
+# 0 "<built-in>"
+#define __UINT_LEAST64_TYPE__ long long unsigned int
+# 0 "<built-in>"
+#define __INT_FAST8_TYPE__ int
+# 0 "<built-in>"
+#define __INT_FAST16_TYPE__ int
+# 0 "<built-in>"
+#define __INT_FAST32_TYPE__ int
+# 0 "<built-in>"
+#define __INT_FAST64_TYPE__ long long int
+# 0 "<built-in>"
+#define __UINT_FAST8_TYPE__ unsigned int
+# 0 "<built-in>"
+#define __UINT_FAST16_TYPE__ unsigned int
+# 0 "<built-in>"
+#define __UINT_FAST32_TYPE__ unsigned int
+# 0 "<built-in>"
+#define __UINT_FAST64_TYPE__ long long unsigned int
+# 0 "<built-in>"
+#define __INTPTR_TYPE__ int
+# 0 "<built-in>"
+#define __UINTPTR_TYPE__ unsigned int
+# 0 "<built-in>"
+#define __GXX_ABI_VERSION 1017
+# 0 "<built-in>"
+#define __SCHAR_MAX__ 0x7f
+# 0 "<built-in>"
+#define __SHRT_MAX__ 0x7fff
+# 0 "<built-in>"
+#define __INT_MAX__ 0x7fffffff
+# 0 "<built-in>"
+#define __LONG_MAX__ 0x7fffffffL
+# 0 "<built-in>"
+#define __LONG_LONG_MAX__ 0x7fffffffffffffffLL
+# 0 "<built-in>"
+#define __WCHAR_MAX__ 0xffffffffU
+# 0 "<built-in>"
+#define __WCHAR_MIN__ 0U
+# 0 "<built-in>"
+#define __WINT_MAX__ 0xffffffffU
+# 0 "<built-in>"
+#define __WINT_MIN__ 0U
+# 0 "<built-in>"
+#define __PTRDIFF_MAX__ 0x7fffffff
+# 0 "<built-in>"
+#define __SIZE_MAX__ 0xffffffffU
+# 0 "<built-in>"
+#define __SCHAR_WIDTH__ 8
+# 0 "<built-in>"
+#define __SHRT_WIDTH__ 16
+# 0 "<built-in>"
+#define __INT_WIDTH__ 32
+# 0 "<built-in>"
+#define __LONG_WIDTH__ 32
+# 0 "<built-in>"
+#define __LONG_LONG_WIDTH__ 64
+# 0 "<built-in>"
+#define __WCHAR_WIDTH__ 32
+# 0 "<built-in>"
+#define __WINT_WIDTH__ 32
+# 0 "<built-in>"
+#define __PTRDIFF_WIDTH__ 32
+# 0 "<built-in>"
+#define __SIZE_WIDTH__ 32
+# 0 "<built-in>"
+#define __INTMAX_MAX__ 0x7fffffffffffffffLL
+# 0 "<built-in>"
+#define __INTMAX_C(c) c ## LL
+# 0 "<built-in>"
+#define __UINTMAX_MAX__ 0xffffffffffffffffULL
+# 0 "<built-in>"
+#define __UINTMAX_C(c) c ## ULL
+# 0 "<built-in>"
+#define __INTMAX_WIDTH__ 64
+# 0 "<built-in>"
+#define __SIG_ATOMIC_MAX__ 0x7fffffff
+# 0 "<built-in>"
+#define __SIG_ATOMIC_MIN__ (-__SIG_ATOMIC_MAX__ - 1)
+# 0 "<built-in>"
+#define __SIG_ATOMIC_WIDTH__ 32
+# 0 "<built-in>"
+#define __INT8_MAX__ 0x7f
+# 0 "<built-in>"
+#define __INT16_MAX__ 0x7fff
+# 0 "<built-in>"
+#define __INT32_MAX__ 0x7fffffffL
+# 0 "<built-in>"
+#define __INT64_MAX__ 0x7fffffffffffffffLL
+# 0 "<built-in>"
+#define __UINT8_MAX__ 0xff
+# 0 "<built-in>"
+#define __UINT16_MAX__ 0xffff
+# 0 "<built-in>"
+#define __UINT32_MAX__ 0xffffffffUL
+# 0 "<built-in>"
+#define __UINT64_MAX__ 0xffffffffffffffffULL
+# 0 "<built-in>"
+#define __INT_LEAST8_MAX__ 0x7f
+# 0 "<built-in>"
+#define __INT8_C(c) c
+# 0 "<built-in>"
+#define __INT_LEAST8_WIDTH__ 8
+# 0 "<built-in>"
+#define __INT_LEAST16_MAX__ 0x7fff
+# 0 "<built-in>"
+#define __INT16_C(c) c
+# 0 "<built-in>"
+#define __INT_LEAST16_WIDTH__ 16
+# 0 "<built-in>"
+#define __INT_LEAST32_MAX__ 0x7fffffffL
+# 0 "<built-in>"
+#define __INT32_C(c) c ## L
+# 0 "<built-in>"
+#define __INT_LEAST32_WIDTH__ 32
+# 0 "<built-in>"
+#define __INT_LEAST64_MAX__ 0x7fffffffffffffffLL
+# 0 "<built-in>"
+#define __INT64_C(c) c ## LL
+# 0 "<built-in>"
+#define __INT_LEAST64_WIDTH__ 64
+# 0 "<built-in>"
+#define __UINT_LEAST8_MAX__ 0xff
+# 0 "<built-in>"
+#define __UINT8_C(c) c
+# 0 "<built-in>"
+#define __UINT_LEAST16_MAX__ 0xffff
+# 0 "<built-in>"
+#define __UINT16_C(c) c
+# 0 "<built-in>"
+#define __UINT_LEAST32_MAX__ 0xffffffffUL
+# 0 "<built-in>"
+#define __UINT32_C(c) c ## UL
+# 0 "<built-in>"
+#define __UINT_LEAST64_MAX__ 0xffffffffffffffffULL
+# 0 "<built-in>"
+#define __UINT64_C(c) c ## ULL
+# 0 "<built-in>"
+#define __INT_FAST8_MAX__ 0x7fffffff
+# 0 "<built-in>"
+#define __INT_FAST8_WIDTH__ 32
+# 0 "<built-in>"
+#define __INT_FAST16_MAX__ 0x7fffffff
+# 0 "<built-in>"
+#define __INT_FAST16_WIDTH__ 32
+# 0 "<built-in>"
+#define __INT_FAST32_MAX__ 0x7fffffff
+# 0 "<built-in>"
+#define __INT_FAST32_WIDTH__ 32
+# 0 "<built-in>"
+#define __INT_FAST64_MAX__ 0x7fffffffffffffffLL
+# 0 "<built-in>"
+#define __INT_FAST64_WIDTH__ 64
+# 0 "<built-in>"
+#define __UINT_FAST8_MAX__ 0xffffffffU
+# 0 "<built-in>"
+#define __UINT_FAST16_MAX__ 0xffffffffU
+# 0 "<built-in>"
+#define __UINT_FAST32_MAX__ 0xffffffffU
+# 0 "<built-in>"
+#define __UINT_FAST64_MAX__ 0xffffffffffffffffULL
+# 0 "<built-in>"
+#define __INTPTR_MAX__ 0x7fffffff
+# 0 "<built-in>"
+#define __INTPTR_WIDTH__ 32
+# 0 "<built-in>"
+#define __UINTPTR_MAX__ 0xffffffffU
+# 0 "<built-in>"
+#define __GCC_IEC_559 0
+# 0 "<built-in>"
+#define __GCC_IEC_559_COMPLEX 0
+# 0 "<built-in>"
+#define __FLT_EVAL_METHOD__ 0
+# 0 "<built-in>"
+#define __FLT_EVAL_METHOD_TS_18661_3__ 0
+# 0 "<built-in>"
+#define __DEC_EVAL_METHOD__ 2
+# 0 "<built-in>"
+#define __FLT_RADIX__ 2
+# 0 "<built-in>"
+#define __FLT_MANT_DIG__ 24
+# 0 "<built-in>"
+#define __FLT_DIG__ 6
+# 0 "<built-in>"
+#define __FLT_MIN_EXP__ (-125)
+# 0 "<built-in>"
+#define __FLT_MIN_10_EXP__ (-37)
+# 0 "<built-in>"
+#define __FLT_MAX_EXP__ 128
+# 0 "<built-in>"
+#define __FLT_MAX_10_EXP__ 38
+# 0 "<built-in>"
+#define __FLT_DECIMAL_DIG__ 9
+# 0 "<built-in>"
+#define __FLT_MAX__ 3.4028234663852886e+38F
+# 0 "<built-in>"
+#define __FLT_NORM_MAX__ 3.4028234663852886e+38F
+# 0 "<built-in>"
+#define __FLT_MIN__ 1.1754943508222875e-38F
+# 0 "<built-in>"
+#define __FLT_EPSILON__ 1.1920928955078125e-7F
+# 0 "<built-in>"
+#define __FLT_DENORM_MIN__ 1.4012984643248171e-45F
+# 0 "<built-in>"
+#define __FLT_HAS_DENORM__ 1
+# 0 "<built-in>"
+#define __FLT_HAS_INFINITY__ 1
+# 0 "<built-in>"
+#define __FLT_HAS_QUIET_NAN__ 1
+# 0 "<built-in>"
+#define __FP_FAST_FMAF 1
+# 0 "<built-in>"
+#define __FLT_IS_IEC_60559__ 2
+# 0 "<built-in>"
+#define __DBL_MANT_DIG__ 53
+# 0 "<built-in>"
+#define __DBL_DIG__ 15
+# 0 "<built-in>"
+#define __DBL_MIN_EXP__ (-1021)
+# 0 "<built-in>"
+#define __DBL_MIN_10_EXP__ (-307)
+# 0 "<built-in>"
+#define __DBL_MAX_EXP__ 1024
+# 0 "<built-in>"
+#define __DBL_MAX_10_EXP__ 308
+# 0 "<built-in>"
+#define __DBL_DECIMAL_DIG__ 17
+# 0 "<built-in>"
+#define __DBL_MAX__ ((double)1.7976931348623157e+308L)
+# 0 "<built-in>"
+#define __DBL_NORM_MAX__ ((double)1.7976931348623157e+308L)
+# 0 "<built-in>"
+#define __DBL_MIN__ ((double)2.2250738585072014e-308L)
+# 0 "<built-in>"
+#define __DBL_EPSILON__ ((double)2.2204460492503131e-16L)
+# 0 "<built-in>"
+#define __DBL_DENORM_MIN__ ((double)4.9406564584124654e-324L)
+# 0 "<built-in>"
+#define __DBL_HAS_DENORM__ 1
+# 0 "<built-in>"
+#define __DBL_HAS_INFINITY__ 1
+# 0 "<built-in>"
+#define __DBL_HAS_QUIET_NAN__ 1
+# 0 "<built-in>"
+#define __DBL_IS_IEC_60559__ 2
+# 0 "<built-in>"
+#define __LDBL_MANT_DIG__ 53
+# 0 "<built-in>"
+#define __LDBL_DIG__ 15
+# 0 "<built-in>"
+#define __LDBL_MIN_EXP__ (-1021)
+# 0 "<built-in>"
+#define __LDBL_MIN_10_EXP__ (-307)
+# 0 "<built-in>"
+#define __LDBL_MAX_EXP__ 1024
+# 0 "<built-in>"
+#define __LDBL_MAX_10_EXP__ 308
+# 0 "<built-in>"
+#define __DECIMAL_DIG__ 17
+# 0 "<built-in>"
+#define __LDBL_DECIMAL_DIG__ 17
+# 0 "<built-in>"
+#define __LDBL_MAX__ 1.7976931348623157e+308L
+# 0 "<built-in>"
+#define __LDBL_NORM_MAX__ 1.7976931348623157e+308L
+# 0 "<built-in>"
+#define __LDBL_MIN__ 2.2250738585072014e-308L
+# 0 "<built-in>"
+#define __LDBL_EPSILON__ 2.2204460492503131e-16L
+# 0 "<built-in>"
+#define __LDBL_DENORM_MIN__ 4.9406564584124654e-324L
+# 0 "<built-in>"
+#define __LDBL_HAS_DENORM__ 1
+# 0 "<built-in>"
+#define __LDBL_HAS_INFINITY__ 1
+# 0 "<built-in>"
+#define __LDBL_HAS_QUIET_NAN__ 1
+# 0 "<built-in>"
+#define __LDBL_IS_IEC_60559__ 2
+# 0 "<built-in>"
+#define __FLT32_MANT_DIG__ 24
+# 0 "<built-in>"
+#define __FLT32_DIG__ 6
+# 0 "<built-in>"
+#define __FLT32_MIN_EXP__ (-125)
+# 0 "<built-in>"
+#define __FLT32_MIN_10_EXP__ (-37)
+# 0 "<built-in>"
+#define __FLT32_MAX_EXP__ 128
+# 0 "<built-in>"
+#define __FLT32_MAX_10_EXP__ 38
+# 0 "<built-in>"
+#define __FLT32_DECIMAL_DIG__ 9
+# 0 "<built-in>"
+#define __FLT32_MAX__ 3.4028234663852886e+38F32
+# 0 "<built-in>"
+#define __FLT32_NORM_MAX__ 3.4028234663852886e+38F32
+# 0 "<built-in>"
+#define __FLT32_MIN__ 1.1754943508222875e-38F32
+# 0 "<built-in>"
+#define __FLT32_EPSILON__ 1.1920928955078125e-7F32
+# 0 "<built-in>"
+#define __FLT32_DENORM_MIN__ 1.4012984643248171e-45F32
+# 0 "<built-in>"
+#define __FLT32_HAS_DENORM__ 1
+# 0 "<built-in>"
+#define __FLT32_HAS_INFINITY__ 1
+# 0 "<built-in>"
+#define __FLT32_HAS_QUIET_NAN__ 1
+# 0 "<built-in>"
+#define __FP_FAST_FMAF32 1
+# 0 "<built-in>"
+#define __FLT32_IS_IEC_60559__ 2
+# 0 "<built-in>"
+#define __FLT64_MANT_DIG__ 53
+# 0 "<built-in>"
+#define __FLT64_DIG__ 15
+# 0 "<built-in>"
+#define __FLT64_MIN_EXP__ (-1021)
+# 0 "<built-in>"
+#define __FLT64_MIN_10_EXP__ (-307)
+# 0 "<built-in>"
+#define __FLT64_MAX_EXP__ 1024
+# 0 "<built-in>"
+#define __FLT64_MAX_10_EXP__ 308
+# 0 "<built-in>"
+#define __FLT64_DECIMAL_DIG__ 17
+# 0 "<built-in>"
+#define __FLT64_MAX__ 1.7976931348623157e+308F64
+# 0 "<built-in>"
+#define __FLT64_NORM_MAX__ 1.7976931348623157e+308F64
+# 0 "<built-in>"
+#define __FLT64_MIN__ 2.2250738585072014e-308F64
+# 0 "<built-in>"
+#define __FLT64_EPSILON__ 2.2204460492503131e-16F64
+# 0 "<built-in>"
+#define __FLT64_DENORM_MIN__ 4.9406564584124654e-324F64
+# 0 "<built-in>"
+#define __FLT64_HAS_DENORM__ 1
+# 0 "<built-in>"
+#define __FLT64_HAS_INFINITY__ 1
+# 0 "<built-in>"
+#define __FLT64_HAS_QUIET_NAN__ 1
+# 0 "<built-in>"
+#define __FLT64_IS_IEC_60559__ 2
+# 0 "<built-in>"
+#define __FLT32X_MANT_DIG__ 53
+# 0 "<built-in>"
+#define __FLT32X_DIG__ 15
+# 0 "<built-in>"
+#define __FLT32X_MIN_EXP__ (-1021)
+# 0 "<built-in>"
+#define __FLT32X_MIN_10_EXP__ (-307)
+# 0 "<built-in>"
+#define __FLT32X_MAX_EXP__ 1024
+# 0 "<built-in>"
+#define __FLT32X_MAX_10_EXP__ 308
+# 0 "<built-in>"
+#define __FLT32X_DECIMAL_DIG__ 17
+# 0 "<built-in>"
+#define __FLT32X_MAX__ 1.7976931348623157e+308F32x
+# 0 "<built-in>"
+#define __FLT32X_NORM_MAX__ 1.7976931348623157e+308F32x
+# 0 "<built-in>"
+#define __FLT32X_MIN__ 2.2250738585072014e-308F32x
+# 0 "<built-in>"
+#define __FLT32X_EPSILON__ 2.2204460492503131e-16F32x
+# 0 "<built-in>"
+#define __FLT32X_DENORM_MIN__ 4.9406564584124654e-324F32x
+# 0 "<built-in>"
+#define __FLT32X_HAS_DENORM__ 1
+# 0 "<built-in>"
+#define __FLT32X_HAS_INFINITY__ 1
+# 0 "<built-in>"
+#define __FLT32X_HAS_QUIET_NAN__ 1
+# 0 "<built-in>"
+#define __FLT32X_IS_IEC_60559__ 2
+# 0 "<built-in>"
+#define __SFRACT_FBIT__ 7
+# 0 "<built-in>"
+#define __SFRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __SFRACT_MIN__ (-0.5HR-0.5HR)
+# 0 "<built-in>"
+#define __SFRACT_MAX__ 0X7FP-7HR
+# 0 "<built-in>"
+#define __SFRACT_EPSILON__ 0x1P-7HR
+# 0 "<built-in>"
+#define __USFRACT_FBIT__ 8
+# 0 "<built-in>"
+#define __USFRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __USFRACT_MIN__ 0.0UHR
+# 0 "<built-in>"
+#define __USFRACT_MAX__ 0XFFP-8UHR
+# 0 "<built-in>"
+#define __USFRACT_EPSILON__ 0x1P-8UHR
+# 0 "<built-in>"
+#define __FRACT_FBIT__ 15
+# 0 "<built-in>"
+#define __FRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __FRACT_MIN__ (-0.5R-0.5R)
+# 0 "<built-in>"
+#define __FRACT_MAX__ 0X7FFFP-15R
+# 0 "<built-in>"
+#define __FRACT_EPSILON__ 0x1P-15R
+# 0 "<built-in>"
+#define __UFRACT_FBIT__ 16
+# 0 "<built-in>"
+#define __UFRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __UFRACT_MIN__ 0.0UR
+# 0 "<built-in>"
+#define __UFRACT_MAX__ 0XFFFFP-16UR
+# 0 "<built-in>"
+#define __UFRACT_EPSILON__ 0x1P-16UR
+# 0 "<built-in>"
+#define __LFRACT_FBIT__ 31
+# 0 "<built-in>"
+#define __LFRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __LFRACT_MIN__ (-0.5LR-0.5LR)
+# 0 "<built-in>"
+#define __LFRACT_MAX__ 0X7FFFFFFFP-31LR
+# 0 "<built-in>"
+#define __LFRACT_EPSILON__ 0x1P-31LR
+# 0 "<built-in>"
+#define __ULFRACT_FBIT__ 32
+# 0 "<built-in>"
+#define __ULFRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __ULFRACT_MIN__ 0.0ULR
+# 0 "<built-in>"
+#define __ULFRACT_MAX__ 0XFFFFFFFFP-32ULR
+# 0 "<built-in>"
+#define __ULFRACT_EPSILON__ 0x1P-32ULR
+# 0 "<built-in>"
+#define __LLFRACT_FBIT__ 63
+# 0 "<built-in>"
+#define __LLFRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __LLFRACT_MIN__ (-0.5LLR-0.5LLR)
+# 0 "<built-in>"
+#define __LLFRACT_MAX__ 0X7FFFFFFFFFFFFFFFP-63LLR
+# 0 "<built-in>"
+#define __LLFRACT_EPSILON__ 0x1P-63LLR
+# 0 "<built-in>"
+#define __ULLFRACT_FBIT__ 64
+# 0 "<built-in>"
+#define __ULLFRACT_IBIT__ 0
+# 0 "<built-in>"
+#define __ULLFRACT_MIN__ 0.0ULLR
+# 0 "<built-in>"
+#define __ULLFRACT_MAX__ 0XFFFFFFFFFFFFFFFFP-64ULLR
+# 0 "<built-in>"
+#define __ULLFRACT_EPSILON__ 0x1P-64ULLR
+# 0 "<built-in>"
+#define __SACCUM_FBIT__ 7
+# 0 "<built-in>"
+#define __SACCUM_IBIT__ 8
+# 0 "<built-in>"
+#define __SACCUM_MIN__ (-0X1P7HK-0X1P7HK)
+# 0 "<built-in>"
+#define __SACCUM_MAX__ 0X7FFFP-7HK
+# 0 "<built-in>"
+#define __SACCUM_EPSILON__ 0x1P-7HK
+# 0 "<built-in>"
+#define __USACCUM_FBIT__ 8
+# 0 "<built-in>"
+#define __USACCUM_IBIT__ 8
+# 0 "<built-in>"
+#define __USACCUM_MIN__ 0.0UHK
+# 0 "<built-in>"
+#define __USACCUM_MAX__ 0XFFFFP-8UHK
+# 0 "<built-in>"
+#define __USACCUM_EPSILON__ 0x1P-8UHK
+# 0 "<built-in>"
+#define __ACCUM_FBIT__ 15
+# 0 "<built-in>"
+#define __ACCUM_IBIT__ 16
+# 0 "<built-in>"
+#define __ACCUM_MIN__ (-0X1P15K-0X1P15K)
+# 0 "<built-in>"
+#define __ACCUM_MAX__ 0X7FFFFFFFP-15K
+# 0 "<built-in>"
+#define __ACCUM_EPSILON__ 0x1P-15K
+# 0 "<built-in>"
+#define __UACCUM_FBIT__ 16
+# 0 "<built-in>"
+#define __UACCUM_IBIT__ 16
+# 0 "<built-in>"
+#define __UACCUM_MIN__ 0.0UK
+# 0 "<built-in>"
+#define __UACCUM_MAX__ 0XFFFFFFFFP-16UK
+# 0 "<built-in>"
+#define __UACCUM_EPSILON__ 0x1P-16UK
+# 0 "<built-in>"
+#define __LACCUM_FBIT__ 31
+# 0 "<built-in>"
+#define __LACCUM_IBIT__ 32
+# 0 "<built-in>"
+#define __LACCUM_MIN__ (-0X1P31LK-0X1P31LK)
+# 0 "<built-in>"
+#define __LACCUM_MAX__ 0X7FFFFFFFFFFFFFFFP-31LK
+# 0 "<built-in>"
+#define __LACCUM_EPSILON__ 0x1P-31LK
+# 0 "<built-in>"
+#define __ULACCUM_FBIT__ 32
+# 0 "<built-in>"
+#define __ULACCUM_IBIT__ 32
+# 0 "<built-in>"
+#define __ULACCUM_MIN__ 0.0ULK
+# 0 "<built-in>"
+#define __ULACCUM_MAX__ 0XFFFFFFFFFFFFFFFFP-32ULK
+# 0 "<built-in>"
+#define __ULACCUM_EPSILON__ 0x1P-32ULK
+# 0 "<built-in>"
+#define __LLACCUM_FBIT__ 31
+# 0 "<built-in>"
+#define __LLACCUM_IBIT__ 32
+# 0 "<built-in>"
+#define __LLACCUM_MIN__ (-0X1P31LLK-0X1P31LLK)
+# 0 "<built-in>"
+#define __LLACCUM_MAX__ 0X7FFFFFFFFFFFFFFFP-31LLK
+# 0 "<built-in>"
+#define __LLACCUM_EPSILON__ 0x1P-31LLK
+# 0 "<built-in>"
+#define __ULLACCUM_FBIT__ 32
+# 0 "<built-in>"
+#define __ULLACCUM_IBIT__ 32
+# 0 "<built-in>"
+#define __ULLACCUM_MIN__ 0.0ULLK
+# 0 "<built-in>"
+#define __ULLACCUM_MAX__ 0XFFFFFFFFFFFFFFFFP-32ULLK
+# 0 "<built-in>"
+#define __ULLACCUM_EPSILON__ 0x1P-32ULLK
+# 0 "<built-in>"
+#define __QQ_FBIT__ 7
+# 0 "<built-in>"
+#define __QQ_IBIT__ 0
+# 0 "<built-in>"
+#define __HQ_FBIT__ 15
+# 0 "<built-in>"
+#define __HQ_IBIT__ 0
+# 0 "<built-in>"
+#define __SQ_FBIT__ 31
+# 0 "<built-in>"
+#define __SQ_IBIT__ 0
+# 0 "<built-in>"
+#define __DQ_FBIT__ 63
+# 0 "<built-in>"
+#define __DQ_IBIT__ 0
+# 0 "<built-in>"
+#define __TQ_FBIT__ 127
+# 0 "<built-in>"
+#define __TQ_IBIT__ 0
+# 0 "<built-in>"
+#define __UQQ_FBIT__ 8
+# 0 "<built-in>"
+#define __UQQ_IBIT__ 0
+# 0 "<built-in>"
+#define __UHQ_FBIT__ 16
+# 0 "<built-in>"
+#define __UHQ_IBIT__ 0
+# 0 "<built-in>"
+#define __USQ_FBIT__ 32
+# 0 "<built-in>"
+#define __USQ_IBIT__ 0
+# 0 "<built-in>"
+#define __UDQ_FBIT__ 64
+# 0 "<built-in>"
+#define __UDQ_IBIT__ 0
+# 0 "<built-in>"
+#define __UTQ_FBIT__ 128
+# 0 "<built-in>"
+#define __UTQ_IBIT__ 0
+# 0 "<built-in>"
+#define __HA_FBIT__ 7
+# 0 "<built-in>"
+#define __HA_IBIT__ 8
+# 0 "<built-in>"
+#define __SA_FBIT__ 15
+# 0 "<built-in>"
+#define __SA_IBIT__ 16
+# 0 "<built-in>"
+#define __DA_FBIT__ 31
+# 0 "<built-in>"
+#define __DA_IBIT__ 32
+# 0 "<built-in>"
+#define __TA_FBIT__ 63
+# 0 "<built-in>"
+#define __TA_IBIT__ 64
+# 0 "<built-in>"
+#define __UHA_FBIT__ 8
+# 0 "<built-in>"
+#define __UHA_IBIT__ 8
+# 0 "<built-in>"
+#define __USA_FBIT__ 16
+# 0 "<built-in>"
+#define __USA_IBIT__ 16
+# 0 "<built-in>"
+#define __UDA_FBIT__ 32
+# 0 "<built-in>"
+#define __UDA_IBIT__ 32
+# 0 "<built-in>"
+#define __UTA_FBIT__ 64
+# 0 "<built-in>"
+#define __UTA_IBIT__ 64
+# 0 "<built-in>"
+#define __REGISTER_PREFIX__ 
+# 0 "<built-in>"
+#define __USER_LABEL_PREFIX__ 
+# 0 "<built-in>"
+#define __GNUC_STDC_INLINE__ 1
+# 0 "<built-in>"
+#define __NO_INLINE__ 1
+# 0 "<built-in>"
+#define __CHAR_UNSIGNED__ 1
+# 0 "<built-in>"
+#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
+# 0 "<built-in>"
+#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
+# 0 "<built-in>"
+#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
+# 0 "<built-in>"
+#define __GCC_ATOMIC_BOOL_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_CHAR_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_CHAR16_T_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_CHAR32_T_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_SHORT_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_INT_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_LONG_LOCK_FREE 2
+# 0 "<built-in>"
+#define __GCC_ATOMIC_LLONG_LOCK_FREE 1
+# 0 "<built-in>"
+#define __GCC_ATOMIC_TEST_AND_SET_TRUEVAL 1
+# 0 "<built-in>"
+#define __GCC_DESTRUCTIVE_SIZE 64
+# 0 "<built-in>"
+#define __GCC_CONSTRUCTIVE_SIZE 64
+# 0 "<built-in>"
+#define __GCC_ATOMIC_POINTER_LOCK_FREE 2
+# 0 "<built-in>"
+#define __HAVE_SPECULATION_SAFE_VALUE 1
+# 0 "<built-in>"
+#define __GCC_HAVE_DWARF2_CFI_ASM 1
+# 0 "<built-in>"
+#define __PRAGMA_REDEFINE_EXTNAME 1
+# 0 "<built-in>"
+#define __SIZEOF_WCHAR_T__ 4
+# 0 "<built-in>"
+#define __SIZEOF_WINT_T__ 4
+# 0 "<built-in>"
+#define __SIZEOF_PTRDIFF_T__ 4
+# 0 "<built-in>"
+#define __ARM_FEATURE_DSP 1
+# 0 "<built-in>"
+#define __ARM_FEATURE_QBIT 1
+# 0 "<built-in>"
+#define __ARM_FEATURE_SAT 1
+# 0 "<built-in>"
+#undef __ARM_FEATURE_CRYPTO
+# 0 "<built-in>"
+#define __ARM_FEATURE_UNALIGNED 1
+# 0 "<built-in>"
+#undef __ARM_FEATURE_QRDMX
+# 0 "<built-in>"
+#undef __ARM_FEATURE_CRC32
+# 0 "<built-in>"
+#undef __ARM_FEATURE_DOTPROD
+# 0 "<built-in>"
+#undef __ARM_FEATURE_COMPLEX
+# 0 "<built-in>"
+#define __ARM_32BIT_STATE 1
+# 0 "<built-in>"
+#undef __ARM_FEATURE_MVE
+# 0 "<built-in>"
+#undef __ARM_FEATURE_CMSE
+# 0 "<built-in>"
+#undef __ARM_FEATURE_LDREX
+# 0 "<built-in>"
+#define __ARM_FEATURE_LDREX 7
+# 0 "<built-in>"
+#define __ARM_FEATURE_CLZ 1
+# 0 "<built-in>"
+#undef __ARM_FEATURE_NUMERIC_MAXMIN
+# 0 "<built-in>"
+#define __ARM_FEATURE_SIMD32 1
+# 0 "<built-in>"
+#define __ARM_SIZEOF_MINIMAL_ENUM 1
+# 0 "<built-in>"
+#define __ARM_SIZEOF_WCHAR_T 4
+# 0 "<built-in>"
+#undef __ARM_ARCH_PROFILE
+# 0 "<built-in>"
+#define __ARM_ARCH_PROFILE 77
+# 0 "<built-in>"
+#define __arm__ 1
+# 0 "<built-in>"
+#undef __ARM_ARCH
+# 0 "<built-in>"
+#define __ARM_ARCH 7
+# 0 "<built-in>"
+#define __APCS_32__ 1
+# 0 "<built-in>"
+#define __GCC_ASM_FLAG_OUTPUTS__ 1
+# 0 "<built-in>"
+#define __thumb__ 1
+# 0 "<built-in>"
+#define __thumb2__ 1
+# 0 "<built-in>"
+#define __THUMBEL__ 1
+# 0 "<built-in>"
+#undef __ARM_ARCH_ISA_THUMB
+# 0 "<built-in>"
+#define __ARM_ARCH_ISA_THUMB 2
+# 0 "<built-in>"
+#define __ARMEL__ 1
+# 0 "<built-in>"
+#define __VFP_FP__ 1
+# 0 "<built-in>"
+#undef __ARM_FP
+# 0 "<built-in>"
+#define __ARM_FP 4
+# 0 "<built-in>"
+#undef __ARM_FP16_FORMAT_IEEE
+# 0 "<built-in>"
+#undef __ARM_FP16_FORMAT_ALTERNATIVE
+# 0 "<built-in>"
+#undef __ARM_FP16_ARGS
+# 0 "<built-in>"
+#undef __ARM_FEATURE_FP16_SCALAR_ARITHMETIC
+# 0 "<built-in>"
+#undef __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
+# 0 "<built-in>"
+#undef __ARM_FEATURE_FP16_FML
+# 0 "<built-in>"
+#define __ARM_FEATURE_FMA 1
+# 0 "<built-in>"
+#undef __ARM_NEON__
+# 0 "<built-in>"
+#undef __ARM_NEON
+# 0 "<built-in>"
+#undef __ARM_NEON_FP
+# 0 "<built-in>"
+#define __THUMB_INTERWORK__ 1
+# 0 "<built-in>"
+#define __ARM_ARCH_7EM__ 1
+# 0 "<built-in>"
+#define __ARM_PCS_VFP 1
+# 0 "<built-in>"
+#define __ARM_EABI__ 1
+# 0 "<built-in>"
+#undef __FDPIC__
+# 0 "<built-in>"
+#define __ARM_ARCH_EXT_IDIV__ 1
+# 0 "<built-in>"
+#define __ARM_FEATURE_IDIV 1
+# 0 "<built-in>"
+#define __ARM_ASM_SYNTAX_UNIFIED__ 1
+# 0 "<built-in>"
+#undef __ARM_FEATURE_COPROC
+# 0 "<built-in>"
+#define __ARM_FEATURE_COPROC 15
+# 0 "<built-in>"
+#undef __ARM_FEATURE_CDE
+# 0 "<built-in>"
+#undef __ARM_FEATURE_CDE_COPROC
+# 0 "<built-in>"
+#undef __ARM_FEATURE_MATMUL_INT8
+# 0 "<built-in>"
+#undef __ARM_FEATURE_BF16_SCALAR_ARITHMETIC
+# 0 "<built-in>"
+#undef __ARM_FEATURE_BF16_VECTOR_ARITHMETIC
+# 0 "<built-in>"
+#undef __ARM_BF16_FORMAT_ALTERNATIVE
+# 0 "<built-in>"
+#define __GXX_TYPEINFO_EQUALITY_INLINE 0
+# 0 "<built-in>"
+#define __ELF__ 1
+# 0 "<command-line>"
+#define __USES_INITFINI__ 1
+# 1 "src/main.c"
+int main(void) {
+  return 42;
+}
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..6883e82
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1718318537,
+        "narHash": "sha256-4Zu0RYRcAY/VWuu6awwq4opuiD//ahpc2aFHg2CWqFY=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "e9ee548d90ff586a6471b4ae80ae9cfcbceb3420",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..ba34c08
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,31 @@
+{
+  description = "c compile experiments";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { nixpkgs, ... }:
+    let
+      systems = [ "x86_64-linux" ];
+    in
+      {
+        config = {
+          nixpkgs.config.allowUnfree = true;
+        };
+
+        devShells = nixpkgs.lib.genAttrs systems (system:
+          let
+            pkgs = nixpkgs.legacyPackages.${system};
+          in
+            {
+              default = pkgs.mkShell {
+                packages = [
+                  pkgs.gnumake
+                  pkgs.gcc-arm-embedded
+                ];
+              };
+            }
+        );
+      };
+}
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..25b1c05
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,3 @@
+int main(void) {
+  return 42;
+}