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Luma3DS-3GX/source/start.s
2016-07-05 16:05:53 +02:00

86 lines
3.0 KiB
ArmAsm

@ This file is part of Luma3DS
@ Copyright (C) 2016 Aurora Wright, TuxSH
@
@ This program is free software: you can redistribute it and/or modify
@ it under the terms of the GNU General Public License as published by
@ the Free Software Foundation, either version 3 of the License, or
@ (at your option) any later version.
@
@ This program is distributed in the hope that it will be useful,
@ but WITHOUT ANY WARRANTY; without even the implied warranty of
@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
@ GNU General Public License for more details.
@
@ You should have received a copy of the GNU General Public License
@ along with this program. If not, see <http://www.gnu.org/licenses/>.
@
@ Additional Terms 7.b of GPLv3 applies to this file: Requiring preservation of specified
@ reasonable legal notices or author attributions in that material or in the Appropriate Legal
@ Notices displayed by works containing it.
@ Thanks to the numerous people who took part in writing this file
.section .text.start
.align 4
.global _start
_start:
b start
.word 0, 0
start:
@ Change the stack pointer
mov sp, #0x27000000
@ Disable caches / MPU
mrc p15, 0, r0, c1, c0, 0 @ read control register
bic r0, #(1<<12) @ - instruction cache disable
bic r0, #(1<<2) @ - data cache disable
bic r0, #(1<<0) @ - mpu disable
mcr p15, 0, r0, c1, c0, 0 @ write control register
@ Flush caches
bl flushEntireDCache
bl flushEntireICache
@ Give read/write access to all the memory regions
ldr r0, =0x3333333
mcr p15, 0, r0, c5, c0, 2 @ write data access
mcr p15, 0, r0, c5, c0, 3 @ write instruction access
@ Set MPU permissions and cache settings
ldr r0, =0xFFFF001D @ ffff0000 32k | bootrom (unprotected part)
ldr r1, =0x01FF801D @ 01ff8000 32k | itcm
ldr r2, =0x08000029 @ 08000000 2M | arm9 mem (O3DS / N3DS)
ldr r3, =0x10000029 @ 10000000 2M | io mem (ARM9 / first 2MB)
ldr r4, =0x20000037 @ 20000000 256M | fcram (O3DS / N3DS)
ldr r5, =0x1FF00027 @ 1FF00000 1M | dsp / axi wram
ldr r6, =0x1800002D @ 18000000 8M | vram (+ 2MB)
mov r7, #0
mov r8, #0x15
mcr p15, 0, r0, c6, c0, 0
mcr p15, 0, r1, c6, c1, 0
mcr p15, 0, r2, c6, c2, 0
mcr p15, 0, r3, c6, c3, 0
mcr p15, 0, r4, c6, c4, 0
mcr p15, 0, r5, c6, c5, 0
mcr p15, 0, r6, c6, c6, 0
mcr p15, 0, r7, c6, c7, 0
mcr p15, 0, r8, c3, c0, 0 @ Write bufferable 0, 2, 4
mcr p15, 0, r8, c2, c0, 0 @ Data cacheable 0, 2, 4
mcr p15, 0, r8, c2, c0, 1 @ Inst cacheable 0, 2, 4
@ Enable caches / MPU
mrc p15, 0, r0, c1, c0, 0 @ read control register
orr r0, r0, #(1<<12) @ - instruction cache enable
orr r0, r0, #(1<<2) @ - data cache enable
orr r0, r0, #(1<<0) @ - mpu enable
mcr p15, 0, r0, c1, c0, 0 @ write control register
@ Fix mounting of SDMC
ldr r0, =0x10000020
mov r1, #0x340
str r1, [r0]
b main