Atmosphere/fusee/loader_stub/source/fusee_loader_start.s
2021-09-06 16:26:50 -07:00

85 lines
2.1 KiB
ArmAsm

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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/>.
*/
.section .crt0._ZN3ams6nxboot6loader5StartEv, "ax", %progbits
.arm
.align 5
.global _ZN3ams6nxboot6loader5StartEv
.type _ZN3ams6nxboot6loader5StartEv, %function
_ZN3ams6nxboot6loader5StartEv:
/* Switch to system mode, mask all interrupts, clear all flags */
msr cpsr_cxsf, #0xDF
/* Relocate main program. */
ldr r0, =_ZN3ams6nxboot6loader5StartEv
adr r1, _ZN3ams6nxboot6loader5StartEv
cmp r0, r1
beq 3f
/* Relocate first 0x100. */
mov r4, #0x100
0:
ldmia r1!, {r5-r12}
stmia r0!, {r5-r12}
subs r4, #0x20
bne 0b
/* Jump, continue relocating. */
ldr r3, =1f
bx r3
1:
ldr r4, =__loader_stub_lma__
ldr r3, =__loader_stub_end__
add r4, r4, r3
ldr r3, =__loader_stub_start__
sub r4, r4, r3
sub r4, r4, r0
2:
ldmia r1!, {r5-r12}
stmia r0!, {r5-r12}
subs r4, #0x20
bne 2b
/* Relocate loader stub. */
3:
ldr r2, =__loader_stub_lma__
ldr r3, =__loader_stub_start__
ldr r4, =__loader_stub_end__
sub r4, r4, r3
4:
ldmia r2!, {r5-r12}
stmia r3!, {r5-r12}
subs r4, #0x20
bne 4b
/* Set the stack pointer */
ldr sp, =0x40001000
mov fp, #0
/* Generate arguments. */
ldr r3, =program_lz4
ldr r4, =program_lz4_end
sub r4, r4, r3
mov r0, r3
mov r1, r4
/* Jump to the loader stub. */
ldr r3, =_ZN3ams6nxboot6loader20UncompressAndExecuteEPKvj
bx r3