Atmosphere/fusee/fusee-mtc/src/start.s

70 lines
No EOL
1.6 KiB
ArmAsm

/*
* Copyright (c) 2018 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/>.
*/
.macro CLEAR_GPR_REG_ITER
mov r\@, #0
.endm
.section .text.start, "ax", %progbits
.arm
.align 5
.global _start
.type _start, %function
_start:
/* Switch to system mode, mask all interrupts, clear all flags */
msr cpsr_cxsf, #0xDF
/* Backup current stack pointer. */
mov r12, sp
/* Set the stack pointer */
ldr sp, =__stack_top__
mov fp, #0
/* Save context */
push {r12, lr}
/* Call init. */
bl __program_init
/* Set r0 to r12 to 0 (for debugging) & call main */
.rept 13
CLEAR_GPR_REG_ITER
.endr
ldr r0, =__program_argc
ldr r1, =__program_argv
ldr r0, [r0]
ldr r1, [r1]
bl main
/* Save result. */
push {r0}
/* Exit manually. */
bl __program_exit
/* Restore result. */
pop {r0}
/* Restore context */
pop {r12}
pop {lr}
/* Restore previous stack pointer. */
mov sp, r12
/* Return */
bx lr