tinySA/demos/ARM7-LPC214x-GCC/crt0.s

147 lines
3.9 KiB
ArmAsm

/*
ChibiOS/RT - Copyright (C) 2006-2007 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/>.
*/
/*
* Generic ARM startup file for ChibiOS/RT.
*/
.extern _main
.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
.equ I_BIT, 0x80
.equ F_BIT, 0x40
.text
.code 32
.balign 4
/*
* System entry points.
*/
_start:
b ResetHandler
ldr pc, _undefined
ldr pc, _swi
ldr pc, _prefetch
ldr pc, _abort
nop
ldr pc, [pc,#-0xFF0] /* VIC - IRQ Vector Register */
ldr pc, _fiq
_undefined:
.word UndHandler
_swi:
.word SwiHandler
_prefetch:
.word PrefetchHandler
_abort:
.word AbortHandler
_fiq:
.word FiqHandler
.word 0
.word 0
/*
* Reset handler.
*/
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
/*
* Check on allocated stacks size. This should never happen unless you
* don't care to verify the map file after compiling your application.
*/
ldr r1, =_bss_end
cmp r0, r1
bge ramsizeok
bl chSysHalt
ramsizeok:
/*
* 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
/*
* Application-provided HW initialization routine.
*/
bl hwinit
/*
* main(0, NULL).
*/
mov r0, #0
mov r1, #0
bl main
bl chSysHalt