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Luma3DS-3GX/exceptions/arm9/source/handlers.s
TuxSH 21db0d45bd Added Rosalina, see details
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2017-06-05 02:02:04 +02:00

114 lines
3.8 KiB
ArmAsm

@ This file is part of Luma3DS
@ Copyright (C) 2016-2017 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 and 7.c of GPLv3 apply 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.
@ * Prohibiting misrepresentation of the origin of that material,
@ or requiring that modified versions of such material be marked in
@ reasonable ways as different from the original version.
.macro GEN_HANDLER name
.global \name
.type \name, %function
\name:
ldr sp, =#0x02000000 @ We make the (full descending) stack point to the end of ITCM for our exception handlers.
@ It doesn't matter if we're overwriting stuff here, since we're going to reboot.
stmfd sp!, {r0-r7} @ FIQ has its own r8-r14 regs
ldr r1, =\@ @ macro expansion counter
b _commonHandler
.size \name, . - \name
.endm
.text
.arm
.align 4
.global _commonHandler
.type _commonHandler, %function
_commonHandler:
mrs r2, spsr
mov r6, sp
mrs r3, cpsr
orr r3, #0x1c0 @ disable Imprecise Aborts, IRQ and FIQ (equivalent to "cpsid aif" on arm11)
msr cpsr_cx, r3
tst r2, #0x20
bne noSvcBreak
cmp r1, #2
bne noSvcBreak
sub r0, lr, #4 @ calling cannotAccessAddress cause more problems that it actually solves... (I've to save a lot of regs and that's a pain tbh)
lsr r0, #20 @ we'll just do some address checks (to see if it's in ARM9 internal memory)
cmp r0, #0x80
bne noSvcBreak
ldr r4, [lr, #-4]
ldr r5, =#0xe12fff7f
cmp r4, r5
bne noSvcBreak
bic r5, r3, #0xf
orr r5, #0x3
msr cpsr_c, r5 @ switch to supervisor mode
ldmfd sp, {r8-r11}^
ldr r2, [sp, #0x1c] @ implementation details of the official svc handler
ldr r4, [sp, #0x18]
msr cpsr_c, r3 @ restore processor mode
tst r2, #0x20
addne lr, r4, #2 @ adjust address for later
moveq lr, r4
noSvcBreak:
ands r4, r2, #0xf @ get the mode that triggered the exception
moveq r4, #0xf @ usr => sys
bic r5, r3, #0xf
orr r5, r4
msr cpsr_c, r5 @ change processor mode
stmfd r6!, {r8-lr}
msr cpsr_c, r3 @ restore processor mode
mov sp, r6
stmfd sp!, {r2,lr} @ it's a bit of a mess, but we will fix that later
@ order of saved regs now: cpsr, pc + (2/4/8), r8-r14, r0-r7
mov r0, sp
b mainHandler
GEN_HANDLER FIQHandler
GEN_HANDLER undefinedInstructionHandler
GEN_HANDLER prefetchAbortHandler
GEN_HANDLER dataAbortHandler
.global readMPUConfig
.type readMPUConfig, %function
readMPUConfig:
stmfd sp!, {r4-r8, lr}
mrc p15,0,r1,c6,c0,0
mrc p15,0,r2,c6,c1,0
mrc p15,0,r3,c6,c2,0
mrc p15,0,r4,c6,c3,0
mrc p15,0,r5,c6,c4,0
mrc p15,0,r6,c6,c5,0
mrc p15,0,r7,c6,c6,0
mrc p15,0,r8,c6,c7,0
stmia r0, {r1-r8}
mrc p15,0,r0,c5,c0,2 @ read data access permission bits
ldmfd sp!, {r4-r8, pc}