@ 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 .extern __agbx_getvbnk .globl agbx_flip .func .thumb_func agbx_flip: @ Get the current value of dispcnt: ldr r0,.dispcntaddr @ agbx_i20 dispcntaddr = 0x4000000u; ldrh r1,[r0] @ agbx_i10 dispcnt = *(agbx_i10 *)dispcntaddr; @ XOR bit five: movs r2,0b10000 eors r1,r2 @ dispcnt ^= 0b10000u; @ Save dispcnt: strh r1,[r0] @ *(agbx_i10 *)dispcntaddr = dispcnt; @ Get the address of the video bank: b __agbx_getvbnk @ agbx_i20 vaddr = __agbx_getvbnk(); bx lr @ return vaddr; .endfunc .align .dispcntaddr: .long 0x4000000