commit fb5ea9c3ec1fc0321d945b925aa712ee2d39d53a
Author: hasslesstech <hasslesstech@tutanota.com>
Date:   Wed Feb 5 00:06:56 2025 +0200

    working code v1

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..322ca2b
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,17 @@
+CROSS_COMPILE = arm-none-eabi-
+
+build: start.S
+	$(CROSS_COMPILE)gcc -x assembler-with-cpp -c -O0 -g3 -mcpu=cortex-m4 -mthumb -Wall -o start.o start.S
+	$(CROSS_COMPILE)gcc start.o -mcpu=cortex-m4 -mthumb -Wall --specs=nosys.specs -nostdlib -lgcc -T./ldscript.ld -o start.elf
+	$(CROSS_COMPILE)objcopy -O binary -F elf32-littlearm start.elf start.bin
+
+qemu: build
+	qemu-system-gnuarmeclipse --verbose --verbose --board STM32F4-Discovery \
+		--mcu STM32F407VG -d unimp,guest_errors \
+		--semihosting-config enable=on,target=native -s -S \
+		--image start.bin
+
+clean:
+	rm *.o
+	rm *.elf
+	rm *.bin
diff --git a/ldscript.ld b/ldscript.ld
new file mode 100644
index 0000000..222b46d
--- /dev/null
+++ b/ldscript.ld
@@ -0,0 +1,7 @@
+MEMORY
+{
+    FLASH ( rx )  : ORIGIN = 0x08000000, LENGTH = 1M
+    RAM   ( rwx ) : ORIGIN = 0x20000000, LENGTH = 128K
+}
+
+__stack_start = ORIGIN(RAM) + LENGTH(RAM);
diff --git a/start.S b/start.S
new file mode 100644
index 0000000..f6794f5
--- /dev/null
+++ b/start.S
@@ -0,0 +1,16 @@
+.syntax unified
+.cpu cortex-m4
+.thumb
+
+.global vtable
+.global reset_handler
+
+.type vtable, %object
+vtable:
+    .word __stack_start
+    .word __hard_reset__+1
+    .size vtable, .-vtable
+
+__hard_reset__:
+    ldr sp, =__stack_start
+    b __hard_reset__