Blinker

format binary
org 0x00000000
use32

GPFSEL1 = 0x20200004
GPSET0 = 0x2020001C
GPCLR0 = 0x20200028
GPSET1 = 0x20200020
GPCLR1 = 0x2020002C

macro movi reg, value {
    ldr reg, [pc]
    b @f
    dw value
@@:
}

Start:
    ;mov r0, #0x8000
    mov r0, #0x10000

Loop:
    movi r1, GPSET0
    ;movi r1, GPSET1
    str r0, [r1]

    bl Pause

    movi r1, GPCLR0
    ;movi r1, GPCLR1
    str r0, [r1]

    bl Pause
    b Loop

Pause:
    movi r2, 1000000
PauseLoop:
    subs r2, #1
    bne PauseLoop
    bx lr