gba arm asm

.data
clr_lim: .short 0x7FFF

.text
.global main

main:
    mov r0, #0x4000000  @init screen
    mov r1, #0x400
    add r1, r1, #3
    str r1, [r0]

    mov r0, #0x6000000
    mov r1, #0x0
    mov r2, #0x7C00
    mov r3, #0x0
    ldr r5, =0xFFFF
    ldr r6, =0xFFFF

loop:
    add r4, r0, r1   @vram offset
    strh r3, [r4]    @store the half-word to the vram
    add r1, r1, #2   @increase vram pointer
    add r3, r3, #1   @increase color
    cmp r1, r6       @check vram limit
    beq reset
    cmp r3, r5       @check color limit
    moveq r2, #0x0

reset:
    mov r1, #0x0
    b loop