mirror of
https://github.com/Atmosphere-NX/Atmosphere.git
synced 2024-12-14 00:33:00 +01:00
87 lines
2.1 KiB
ArmAsm
87 lines
2.1 KiB
ArmAsm
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/*
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* Copyright (c) 2018 Atmosphère-NX
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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.macro CLEAR_GPR_REG_ITER
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mov r\@, #0
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.endm
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.section .text.start, "ax", %progbits
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.arm
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.align 5
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.global _start
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.type _start, %function
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_start:
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/* Switch to system mode, mask all interrupts, clear all flags */
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msr cpsr_cxsf, #0xDF
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/* Relocate ourselves if necessary */
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ldr r2, =__start__
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adr r3, _start
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cmp r2, r3
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beq _relocation_loop_end
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ldr r4, =_relocation_loop_end
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mov r4, #0x1000
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mov r1, #0x0
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_relocation_loop:
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ldmia r3!, {r5-r12}
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stmia r2!, {r5-r12}
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add r1, r1, #0x20
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cmp r1, r4
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bne _relocation_loop
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ldr r12, =_second_relocation_start
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bx r12
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_second_relocation_start:
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ldr r4, =__bss_start__
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sub r4, r4, r2
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mov r1, #0x0
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_second_relocation_loop:
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ldmia r3!, {r5-r12}
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stmia r2!, {r5-r12}
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add r1, r1, #0x20
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cmp r1, r4
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bne _second_relocation_loop
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ldr r12, =_relocation_loop_end
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bx r12
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_relocation_loop_end:
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/* Set the stack pointer */
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ldr sp, =__stack_top__
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mov fp, #0
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bl __program_init
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/* Set r0 to r12 to 0 (for debugging) & call main */
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.rept 13
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CLEAR_GPR_REG_ITER
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.endr
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ldr lr, =__program_exit
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b main
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/* No need to include this in normal programs: */
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.section .chainloader.text.start, "ax", %progbits
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.arm
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.align 5
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.global relocate_and_chainload
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.type relocate_and_chainload, %function
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relocate_and_chainload:
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ldr sp, =__stack_top__
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b relocate_and_chainload_main
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