| /*************************************************************************** |
| * __________ __ ___. |
| * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| * \/ \/ \/ \/ \/ |
| * $Id$ |
| * |
| * Copyright (C) 2002 by Linus Nielsen Feltzing |
| * |
| * Arm bootloader and startup code based on startup.s from the iPodLinux loader |
| * |
| * Copyright (c) 2003, Daniel Palffy (dpalffy (at) rainstorm.org) |
| * Copyright (c) 2005, Bernard Leach <leachbj@bouncycastle.org> |
| * |
| * All files in this archive are subject to the GNU General Public License. |
| * See the file COPYING in the source tree root for full license agreement. |
| * |
| * 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: |
| msr cpsr, #0xd3 /* enter supervisor mode, disable IRQ */ |
| |
| #if !defined(DEBUG) |
| /* Copy exception handler code to address 0 */ |
| ldr r2, =_vectorsstart |
| ldr r3, =_vectorsend |
| ldr r4, =_vectorscopy |
| 1: |
| cmp r3, r2 |
| ldrhi r5, [r4], #4 |
| strhi r5, [r2], #4 |
| bhi 1b |
| #else |
| ldr r1, =vectors |
| ldr r0, =irq_handler |
| str r0, [r1, #24] |
| ldr r0, =fiq_handler |
| str r0, [r1, #28] |
| #endif |
| |
| /* Disable high vectors (at 0xffff0000 instead of 0x00000000) */ |
| mrc p15, 0, r0, c1, c0 |
| and r0, r0, #~(1<<13) |
| mcr p15, 0, r0, c1, c0 |
| |
| #if !defined(BOOTLOADER) |
| |
| #if !defined(STUB) |
| /* Zero out IBSS */ |
| ldr r2, =_iedata |
| ldr r3, =_iend |
| mov r4, #0 |
| 1: |
| cmp r3, r2 |
| strhi r4, [r2], #4 |
| bhi 1b |
| |
| /* Copy the IRAM */ |
| ldr r2, =_iramcopy |
| ldr r3, =_iramstart |
| ldr r4, =_iramend |
| 1: |
| cmp r4, r3 |
| ldrhi r5, [r2], #4 |
| strhi r5, [r3], #4 |
| bhi 1b |
| #endif /* !STUB */ |
| #endif /* !BOOTLOADER */ |
| |
| /* 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 r3, =stackend |
| ldr r2, =stackbegin |
| ldr r4, =0xdeadbeef |
| 1: |
| cmp r3, r2 |
| strhi r4, [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 to supervisor mode (no IRQ) */ |
| msr cpsr_c, #0xd3 |
| ldr sp, =stackend |
| |
| #ifdef BOOTLOADER |
| /* get the high part of our execute address */ |
| ldr r2, =0xffffff00 |
| and r4, pc, r2 |
| |
| /* Copy bootloader to safe area - 0x01900000 */ |
| mov r5, #0x00900000 |
| add r5, r5, #0x01000000 |
| ldr r6, = _dataend |
| sub r0, r6, r5 /* length of loader */ |
| add r0, r4, r0 /* r0 points to start of loader */ |
| 1: |
| cmp r5, r6 |
| ldrcc r2, [r4], #4 |
| strcc r2, [r5], #4 |
| bcc 1b |
| |
| ldr pc, =start_loc /* jump to the relocated start_loc: */ |
| |
| #endif |
| |
| start_loc: |
| bl main |
| /* main() should never return */ |
| |
| /* Exception handlers. Will be copied to address 0 after memory remapping */ |
| .section .vectors,"aw" |
| ldr pc, [pc, #24] |
| ldr pc, [pc, #24] |
| ldr pc, [pc, #24] |
| ldr pc, [pc, #24] |
| ldr pc, [pc, #24] |
| ldr pc, [pc, #24] |
| ldr pc, [pc, #24] |
| ldr pc, [pc, #24] |
| |
| /* Exception vectors */ |
| .global vectors |
| vectors: |
| .word start |
| .word undef_instr_handler |
| .word software_int_handler |
| .word prefetch_abort_handler |
| .word data_abort_handler |
| .word reserved_handler |
| .word irq_handler |
| .word fiq_handler |
| |
| .text |
| |
| #if !defined(STUB) |
| .global irq |
| .global fiq |
| .global UIE |
| #endif |
| |
| /* 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 |
| |
| UIE: |
| b UIE |
| |
| /* 256 words of IRQ stack */ |
| .space 256*4 |
| irq_stack: |
| |
| /* 256 words of FIQ stack */ |
| .space 256*4 |
| fiq_stack: |