crt0.s
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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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.
ChibiOS/RT 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/>.
---
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes ChibiOS/RT, without being obliged to provide
the source code for any proprietary components. See the file exception.txt
for full details of how and when the exception can be applied.
*/
/**
* @file ARM/crt0.s
* @brief Generic ARM7/9 startup file for ChibiOS/RT.
*
* @addtogroup ARM_CORE
* @{
*/
#if !defined(__DOXYGEN__)
.set MODE_USR, 0x10
.set MODE_FIQ, 0x11
.set MODE_IRQ, 0x12
.set MODE_SVC, 0x13
.set MODE_ABT, 0x17
.set MODE_UND, 0x1B
.set MODE_SYS, 0x1F
.set I_BIT, 0x80
.set F_BIT, 0x40
.text
.code 32
.balign 4
/*
* Reset handler.
*/
.global ResetHandler
ResetHandler:
/*
* Stack pointers initialization.
*/
ldr r0, =__ram_end__
/* Undefined */
msr CPSR_c, #MODE_UND | I_BIT | F_BIT
mov sp, r0
ldr r1, =__und_stack_size__
sub r0, r0, r1
/* Abort */
msr CPSR_c, #MODE_ABT | I_BIT | F_BIT
mov sp, r0
ldr r1, =__abt_stack_size__
sub r0, r0, r1
/* FIQ */
msr CPSR_c, #MODE_FIQ | I_BIT | F_BIT
mov sp, r0
ldr r1, =__fiq_stack_size__
sub r0, r0, r1
/* IRQ */
msr CPSR_c, #MODE_IRQ | I_BIT | F_BIT
mov sp, r0
ldr r1, =__irq_stack_size__
sub r0, r0, r1
/* Supervisor */
msr CPSR_c, #MODE_SVC | I_BIT | F_BIT
mov sp, r0
ldr r1, =__svc_stack_size__
sub r0, r0, r1
/* System */
msr CPSR_c, #MODE_SYS | I_BIT | F_BIT
mov sp, r0
// ldr r1, =__sys_stack_size__
// sub r0, r0, r1
/*
* Early initialization.
*/
#ifndef THUMB_NO_INTERWORKING
bl __early_init
#else
add r0, pc, #1
bx r0
.code 16
bl __early_init
mov r0, pc
bx r0
.code 32
#endif
/*
* Data initialization.
* NOTE: It assumes that the DATA size is a multiple of 4.
*/
ldr r1, =_textdata
ldr r2, =_data
ldr r3, =_edata
dataloop:
cmp r2, r3
ldrlo r0, [r1], #4
strlo r0, [r2], #4
blo dataloop
/*
* BSS initialization.
* NOTE: It assumes that the BSS size is a multiple of 4.
*/
mov r0, #0
ldr r1, =_bss_start
ldr r2, =_bss_end
bssloop:
cmp r1, r2
strlo r0, [r1], #4
blo bssloop
/*
* Main program invocation.
*/
#ifdef THUMB_NO_INTERWORKING
add r0, pc, #1
bx r0
.code 16
bl main
ldr r1, =_main_exit_handler
bx r1
.code 32
#else
bl main
b _main_exit_handler
#endif
/*
* Default main function exit handler.
*/
.weak _main_exit_handler
.global _main_exit_handler
_main_exit_handler:
.loop: b .loop
/*
* Default early initialization code. It is declared weak in order to be
* replaced by the real initialization code.
* Early initialization is performed just after reset before BSS and DATA
* segments initialization.
*/
#ifdef THUMB_NO_INTERWORKING
.thumb_func
.code 16
#endif
.weak __early_init
hwinit0:
bx lr
.code 32
#endif
/** @} */