mirror of
https://github.com/suchmememanyskill/TegraExplorer.git
synced 2024-11-08 13:11:54 +00:00
77 lines
1.7 KiB
ArmAsm
77 lines
1.7 KiB
ArmAsm
/*
|
|
* Copyright (c) 2018 naehrwert
|
|
*
|
|
* 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 .text._start
|
|
.arm
|
|
|
|
.extern _reloc_ipl
|
|
.type _reloc_ipl, %function
|
|
|
|
.extern memset
|
|
.type memset, %function
|
|
|
|
.extern _irq_setup
|
|
.type _irq_setup, %function
|
|
|
|
.globl _start
|
|
.type _start, %function
|
|
_start:
|
|
ADR R0, _start
|
|
LDR R1, =__ipl_start
|
|
CMP R0, R1
|
|
BEQ _real_start
|
|
|
|
/* If we are not in the right location already, copy a relocator to upper IRAM. */
|
|
ADR R2, _reloc_ipl
|
|
LDR R3, =0x4003FF00
|
|
MOV R4, #(_real_start - _reloc_ipl)
|
|
_copy_loop:
|
|
LDMIA R2!, {R5}
|
|
STMIA R3!, {R5}
|
|
SUBS R4, #4
|
|
BNE _copy_loop
|
|
|
|
/* Use the relocator to copy ourselves into the right place. */
|
|
LDR R2, =__ipl_end
|
|
SUB R2, R2, R1
|
|
LDR R3, =_real_start
|
|
LDR R4, =0x4003FF00
|
|
BX R4
|
|
|
|
_reloc_ipl:
|
|
LDMIA R0!, {R4-R7}
|
|
STMIA R1!, {R4-R7}
|
|
SUBS R2, #0x10
|
|
BNE _reloc_ipl
|
|
/* Jump to the relocated entry. */
|
|
BX R3
|
|
|
|
_real_start:
|
|
/* Initially, we place our stack in IRAM but will move it to SDRAM later. */
|
|
LDR SP, =0x4003FF00
|
|
LDR R0, =__bss_start
|
|
EOR R1, R1, R1
|
|
LDR R2, =__bss_end
|
|
SUB R2, R2, R0
|
|
BL memset
|
|
BL _irq_setup
|
|
B .
|
|
|
|
.globl pivot_stack
|
|
.type pivot_stack, %function
|
|
pivot_stack:
|
|
MOV SP, R0
|
|
BX LR
|