| /*************************************************************************** |
| * __________ __ ___. |
| * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| * \/ \/ \/ \/ \/ |
| * $Id$ |
| * |
| * Copyright (C) 2008 by Marcoen Hirschberg |
| * |
| * This program 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 2 |
| * of the License, or (at your option) any later version. |
| * |
| * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY |
| * KIND, either express or implied. |
| * |
| ****************************************************************************/ |
| #include "config.h" |
| #include "cpu.h" |
| |
| .section .init.text,"ax",%progbits |
| |
| .global start |
| start: |
| /* Exception vectors */ |
| b newstart |
| b undef_instr_handler |
| b software_int_handler |
| b prefetch_abort_handler |
| b data_abort_handler |
| b reserved_handler |
| b irq_handler |
| b fiq_handler |
| .word 0x43554644 /* DFUC */ |
| |
| newstart: |
| #if 0 |
| msr cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ/FIQ */ |
| |
| /* Initialise bss section to zero */ |
| ldr r2, =_edata |
| ldr r3, =_end |
| mov r4, #0 |
| 1: |
| cmp r3, r2 |
| strhi r4, [r2], #4 |
| bhi 1b |
| |
| /* Set up some stack and munge it with 0xdeadbeef */ |
| ldr sp, =stackend |
| ldr r2, =stackbegin |
| ldr r3, =0xdeadbeef |
| 1: |
| cmp sp, r2 |
| strhi r3, [r2], #4 |
| bhi 1b |
| |
| /* Set up stack for IRQ mode */ |
| msr cpsr_c, #0xd2 |
| ldr sp, =irq_stack |
| |
| /* Set up stack for FIQ mode */ |
| msr cpsr_c, #0xd1 |
| ldr sp, =fiq_stack |
| |
| /* Let abort and undefined modes use IRQ stack */ |
| msr cpsr_c, #0xd7 |
| ldr sp, =irq_stack |
| msr cpsr_c, #0xdb |
| ldr sp, =irq_stack |
| |
| /* Switch back to supervisor mode */ |
| msr cpsr_c, #0xd3 |
| #endif |
| bl main |
| |
| |
| .text |
| /* .global UIE*/ |
| |
| /* All illegal exceptions call into UIE with exception address as first |
| * parameter. This is calculated differently depending on which exception |
| * we're in. Second parameter is exception number, used for a string lookup |
| * in UIE. */ |
| undef_instr_handler: |
| mov r0, lr |
| mov r1, #0 |
| b UIE |
| |
| /* We run supervisor mode most of the time, and should never see a software |
| * exception being thrown. Perhaps make it illegal and call UIE? */ |
| software_int_handler: |
| reserved_handler: |
| movs pc, lr |
| |
| prefetch_abort_handler: |
| sub r0, lr, #4 |
| mov r1, #1 |
| b UIE |
| |
| data_abort_handler: |
| sub r0, lr, #8 |
| mov r1, #2 |
| b UIE |
| |
| /* 256 words of IRQ stack */ |
| .space 256*4 |
| irq_stack: |
| |
| /* 256 words of FIQ stack */ |
| .space 256*4 |
| fiq_stack: |
| |
| end: |
| /*.word 0xA5A5A5A5 |
| .word 0x5A5A5A5A*/ |