.section .startup
.code 32
- ldr sp, =_stacktop
+startup:
+ @ stop all but one of the cores
+ mrc p15, 0, r0, c0, c0, 5
+ ands r0, r0, #0xff
+ bne exit
- mov r0, #1
- bl dbgled
+ @ setup stack
+ ldr sp, =_stacktop
@ clear bss
ldr r0, =_bss_start
subs r1, #4
bne 0b
1:
- bl main
-
- mov r0, #0
- bl dbgled
-
-halt: wfe
- b halt
+ blx main
-dbgled:
- ldr r3, =0x3f200000 @ gpio base
- ldr r2, =0x9000 @ gpio 24 and 25 -> output
- str r2, [r3, #8] @ store to GPFSEL2
- ldr r2, =0x01000000 @ bit 24
- teq r0, #0
- streq r2, [r3, #0x1c] @ GPSET0
- strne r2, [r3, #0x28] @ GPCLR0
- lsl r2, #1
- strne r2, [r3, #0x1c] @ GPSET0
- streq r2, [r3, #0x28] @ GPCLR0
- bx lr
+ .global exit
+exit: wfe
+ b exit
@ vi:set filetype=armasm: