1 files changed, 34 insertions, 0 deletions
diff --git a/STM32F429ZIT6_HelloWorld/boot.S b/STM32F429ZIT6_HelloWorld/boot.S
new file mode 100644
index 0000000..81e0a47
--- /dev/null
+++ b/STM32F429ZIT6_HelloWorld/boot.S
@@ -0,0 +1,34 @@
+.syntax unified
+.cpu cortex-m4
+.fpu vfp
+.thumb
+.global reset_handler
+.type reset_handler, %function
+reset_handler:
+    LDR r0, =_estack
+    MOV sp, r0
+    MOVS r0, #0
+    LDR r1, =_sdata
+    LDR r2, =_edata
+    LDR r3, =_sidata
+    B copy_sidata_loop
+    copy_sidata:
+        LDR r4, [r3, r0]
+        STR r4, [r1, r0]
+        ADDS r0, r0, #4
+    copy_sidata_loop:
+        ADDS r4, r0, r1
+        CMP r4, r2
+        BCC copy_sidata
+    MOVS r0, #0
+    LDR r1, =_sbss
+    LDR r2, =_ebss
+    B reset_bss_loop
+    reset_bss:
+        STR r0, [r1]
+        ADDS r1, r1, #4
+    reset_bss_loop:
+        CMP r1, r2
+        BCC reset_bss
+    B main
+.size reset_handler, .-reset_handler
+\ No newline at end of file