/**
* @file
*
* @brief Boot and system start code.
*/
/*
* Copyright (c) 2008
* Embedded Brains GmbH
* Obere Lagerstr. 30
* D-82178 Puchheim
* Germany
* rtems@embedded-brains.de
*
* The license and distribution terms for this file may be found in the file
* LICENSE in this distribution or at http://www.rtems.com/license/LICENSE.
*/
#include <bsp/linker-symbols.h>
#include <bsp/start.h>
/* External symbols */
.extern bsp_reset
.extern boot_card
/* Global symbols */
.globl start
.globl SWI_Handler
/* Program Status Register definitions */
.equ PSR_MODE_USR, 0x10
.equ PSR_MODE_FIQ, 0x11
.equ PSR_MODE_IRQ, 0x12
.equ PSR_MODE_SVC, 0x13
.equ PSR_MODE_ABT, 0x17
.equ PSR_MODE_UNDEF, 0x1b
.equ PSR_MODE_SYS, 0x1f
.equ PSR_I, 0x80
.equ PSR_F, 0x40
.equ PSR_T, 0x20
.section ".entry"
/*
* This is the exception vector table and the pointers to the default
* exceptions handlers.
*/
vector_block:
ldr pc, handler_addr_reset
ldr pc, handler_addr_undef
ldr pc, handler_addr_swi
ldr pc, handler_addr_prefetch
ldr pc, handler_addr_abort
/* Program signature checked by boot loader */
.word 0xb8a06f58
ldr pc, handler_addr_irq
ldr pc, handler_addr_fiq
handler_addr_reset:
.word start
handler_addr_undef:
.word twiddle
handler_addr_swi:
.word twiddle
handler_addr_prefetch:
.word twiddle
handler_addr_abort:
.word twiddle
handler_addr_reserved:
.word twiddle
handler_addr_irq:
.word twiddle
handler_addr_fiq:
.word twiddle
/* Start entry */
start:
/*
* We do not save the context since we do not return to the boot
* loader.
*/
/*
* Set SVC mode, disable interrupts and enable ARM instructions.
*/
mov r0, #(PSR_MODE_SVC | PSR_I | PSR_F)
msr cpsr, r0
/* Initialize stack pointer registers for the various modes */
/* Enter IRQ mode and set up the IRQ stack pointer */
mov r0, #(PSR_MODE_IRQ | PSR_I | PSR_F)
msr cpsr, r0
ldr r1, =bsp_stack_irq_size
ldr sp, =bsp_stack_irq_start
add sp, sp, r1
/* Enter FIQ mode and set up the FIQ stack pointer */
mov r0, #(PSR_MODE_FIQ | PSR_I | PSR_F)
msr cpsr, r0
ldr r1, =bsp_stack_fiq_size
ldr sp, =bsp_stack_fiq_start
add sp, sp, r1
/* Enter ABT mode and set up the ABT stack pointer */
mov r0, #(PSR_MODE_ABT | PSR_I | PSR_F)
msr cpsr, r0
ldr r1, =bsp_stack_abt_size
ldr sp, =bsp_stack_abt_start
add sp, sp, r1
/* Enter UNDEF mode and set up the UNDEF stack pointer */
mov r0, #(PSR_MODE_UNDEF | PSR_I | PSR_F)
msr cpsr, r0
ldr r1, =bsp_stack_undef_size
ldr sp, =bsp_stack_undef_start
add sp, sp, r1
/* Enter SVC mode and set up the SVC stack pointer */
mov r0, #(PSR_MODE_SVC | PSR_I | PSR_F)
msr cpsr, r0
ldr r1, =bsp_stack_svc_size
ldr sp, =bsp_stack_svc_start
add sp, sp, r1
/* Stay in SVC mode */
/* Brach to start hook 0 */
bl bsp_start_hook_0
/*
* Initialize the exception vectors. This includes the exceptions
* vectors and the pointers to the default exception handlers.
*/
ldr r0, =bsp_section_vector_start
adr r1, vector_block
ldmia r1!, {r2-r9}
stmia r0!, {r2-r9}
ldmia r1!, {r2-r9}
stmia r0!, {r2-r9}
/* Brach to start hook 1 */
bl bsp_start_hook_1
/* Brach to boot card */
bl boot_card
/* Branch to reset function */
bl bsp_reset
/* Spin forever */
SWI_Handler:
twiddle:
b twiddle
