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Luma3DS-3GX/source/start.s
TuxSH 88891ef6cd Setting "Dev. Options" to "None" no longer disable exception handling and related patches.
Removed the patch that disables execution protection on the global kernel FCRAM and VRAM mapping as it was unused, worthless, and caused bugs in the past.
2016-08-13 15:31:08 +02:00

87 lines
3.1 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<<13) @ - alternate exception vectors enable
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