/*
* Cogent CSB336 startup code
*
* Copyright (c) 2004 by Jay Monkman <jtm@lopingdog.com>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
*
* http://www.OARcorp.com/rtems/license.html.
*
*
* $Id$
*/
/* Some standard 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
.text
.globl _start
_start:
b _start2
@---------------------------------------------------------------------------------
@ AXF addresses
@---------------------------------------------------------------------------------
.word _text_start
.word _ro_end
.word _data_start
.word _bss_end
.word _bss_start
.word _bss_end
@---------------------------------------------------------------------------------
@ GamePark magic sequence
@---------------------------------------------------------------------------------
.word 0x44450011
.word 0x44450011
.word 0x01234567
.word 0x12345678
.word 0x23456789
.word 0x34567890
.word 0x45678901
.word 0x56789012
.word 0x23456789
.word 0x34567890
.word 0x45678901
.word 0x56789012
.word 0x23456789
.word 0x34567890
.word 0x45678901
.word 0x56789012
@---------------------------------------------------------------------------------
_start2:
@---------------------------------------------------------------------------------
/*
* Since I don't plan to return to the bootloader,
* I don't have to save the registers.
*
* I'll just set the CPSR for SVC mode, interrupts
* off, and ARM instructions.
*/
mov r0, #(PSR_MODE_SVC | PSR_I | PSR_F)
msr cpsr, r0
/* zero the bss */
ldr r1, =_bss_end_
ldr r0, =_bss_start_
_bss_init:
mov r2, #0
cmp r0, r1
strlot r2, [r0], #4
blo _bss_init /* loop while r0 < r1 */
/* --- Initialize stack pointer registers */
/* Enter IRQ mode and set up the IRQ stack pointer */
mov r0, #(PSR_MODE_IRQ | PSR_I | PSR_F) /* No interrupts */
msr cpsr, r0
ldr r1, =_irq_stack_size
ldr sp, =_irq_stack
add sp, sp, r1
/* Enter FIQ mode and set up the FIQ stack pointer */
mov r0, #(PSR_MODE_FIQ | PSR_I | PSR_F) /* No interrupts */
msr cpsr, r0
ldr r1, =_fiq_stack_size
ldr sp, =_fiq_stack
add sp, sp, r1
/* Enter ABT mode and set up the ABT stack pointer */
mov r0, #(PSR_MODE_ABT | PSR_I | PSR_F) /* No interrupts */
msr cpsr, r0
ldr r1, =_abt_stack_size
ldr sp, =_abt_stack
add sp, sp, r1
/* Set up the SVC stack pointer last and stay in SVC mode */
mov r0, #(PSR_MODE_SVC | PSR_I | PSR_F) /* No interrupts */
msr cpsr, r0
ldr r1, =_svc_stack_size
ldr sp, =_svc_stack
add sp, sp, r1
sub sp, sp, #0x64
/*
* Initialize the MMU. After we return, the MMU is enabled,
* and memory may be remapped. I hope we don't remap this
* memory away.
*/
ldr r0, =mem_map
bl mmu_init
/*
* Initialize the exception vectors. This includes the
* exceptions vectors (0x00000000-0x0000001c), and the
* pointers to the exception handlers (0x00000020-0x0000003c).
*/
mov r0, #0
adr r1, vector_block
ldmia r1!, {r2-r9}
stmia r0!, {r2-r9}
ldmia r1!, {r2-r9}
stmia r0!, {r2-r9}
/* Now we are prepared to start the BSP's C code */
bl boot_card
/*
* Theoretically, we could return to what started us up,
* but we'd have to have saved the registers and stacks.
* Instead, we'll just reset.
*/
bl bsp_reset
/* We shouldn't get here. If we do, hang */
_hang: b _hang
/*
* This is the exception vector table and the pointers to
* the functions that handle the exceptions. It's a total
* of 16 words (64 bytes)
*/
vector_block:
ldr pc, Reset_Handler
ldr pc, Undefined_Handler
ldr pc, SWI_Handler
ldr pc, Prefetch_Handler
ldr pc, Abort_Handler
nop
ldr pc, IRQ_Handler
ldr pc, FIQ_Handler
Reset_Handler: b bsp_reset
Undefined_Handler: b Undefined_Handler
SWI_Handler: b SWI_Handler
Prefetch_Handler: b Prefetch_Handler
Abort_Handler: b Abort_Handler
nop
IRQ_Handler: b IRQ_Handler
FIQ_Handler: b FIQ_Handler
.globl Reset_Handler
.globl Undefined_Handler
.globl SWI_Handler
.globl Prefetch_Handler
.globl Abort_Handler
.globl IRQ_Handler
.globl FIQ_Handler
