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@ Copyright 2022 Gabriel Jensen.
@ This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
@ If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
.syntax unified
.cpu arm7tdmi
.thumb
.globl agbx_vsync
.func
.thumb_func
agbx_vsync:
@ Set the constants:
ldr r0,.scancnt @ Address of the scanline counter register.
movs r1,0xA0 @ Number of horizontal lines;
.loop:
@ Check the scanline counter:
ldr r2,[r0] @ Load the counter.
cmp r2,r1 @ Check if it has reached the bottom.
beq .ret @ Return if so.
.ret:
@ Return:
bx lr
.endfunc
.align
.scancnt:
.long 0x4000000
.align
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