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Luma3DS-3GX/loader/source/cache.s
2016-09-23 19:03:59 +02:00

55 lines
2.0 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.
.text
.arm
.align 4
.global flushCaches
.type flushCaches, %function
flushCaches:
@ Clean and flush data cache
@ Adpated from http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0155a/ch03s03s05.html ,
@ and https://github.com/gemarcano/libctr9_io/blob/master/src/ctr_system_ARM.c#L39 as well
@ Note: ARM's example is actually for a 8KB DCache (which is what the 3DS has)
@ Implemented in bootROM at address 0xffff0830
mov r1, #0 @ segment counter
outer_loop:
mov r0, #0 @ line counter
inner_loop:
orr r2, r1, r0 @ generate segment and line address
mcr p15, 0, r2, c7, c14, 2 @ clean and flush the line
add r0, #0x20 @ increment to next line
cmp r0, #0x400
bne inner_loop
add r1, #0x40000000
cmp r1, #0
bne outer_loop
mcr p15, 0, r1, c7, c10, 4 @ drain write buffer
@ Flush instruction cache
mcr p15, 0, r1, c7, c5, 0
bx lr