- .equ STACK_TOP, 0x20000800
+ .equ STACK_TOP, 0x20008000 /* placed at 32kB, TODO: could place at top of SRAM? */
.text
.global _start
+ .global reset, nmi, hardfault
.code 16
.syntax unified
_start:
- .word STACK_TOP, start
- .type start, function
+ .word STACK_TOP, reset, nmi, hardfault
+ .type reset, function
-/* Start of main program */
-start:
- movs r0, #10
- movs r1, #5
-loop:
- adds r1, r0
- subs r0, #1
- bne loop
-/* Result is now in R1 */
-deadloop:
- b deadloop
+/* A reset vector (or bootcode) will call main in main.c
+ this is the so called 'entry to C' */
+reset:
+ b main
+ b reset
+
+/* These are consequently the nmi and hardfault vector handlers
+ before booting and entering main, these can actually be called
+ (machine somehow has a failure). That's why they are included here.
+ Later the interrupt vector
+ will be relocated to SRAM and the will be copied / modified. */
+
+nmi:
+ b nmi
+
+hardfault:
+ b hardfault
+.global stub
+stub:
+ mov r1, #'z'
+ ldr r0, [r1]
+ bx lr
+ /* ldr R0,=10
+ mov R1,#0
+ udiv.w R2, R0, R1 */
+
+ .data
+ .word 'x'
.end