| /*************************************************************************** |
| * __________ __ ___. |
| * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| * \/ \/ \/ \/ \/ |
| * $Id$ |
| * |
| * Copyright (C) 2002 by Linus Nielsen Feltzing |
| * |
| * 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. |
| * |
| ****************************************************************************/ |
| |
| /* 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> |
| * |
| */ |
| |
| #include "config.h" |
| #include "cpu.h" |
| |
| .section .init.text,"ax",%progbits |
| |
| .extern irq |
| .extern fiq |
| .extern UIE |
| .extern main |
| |
| .global start |
| |
| /* Telechips firmware files start with a 32-byte header, as part of the code. */ |
| |
| start: |
| #ifdef TCCBOOT |
| /* Add -DTCCBOOT to EXTRA_DEFINES in the bootloader Makefile to |
| enable building the bootloader to be appended to the end of the |
| original firmware, dual-booting based on a key-press. |
| |
| The following two values are filled in by mktccboot. |
| */ |
| .word 0 /* Saved entrypoint of original firmware*/ |
| .word 0 /* Location in RAM of the start of our bootloader */ |
| #else |
| // ldr pc, =start_loc /* jump to the main entry point */ |
| b start_loc |
| |
| .word 0xffff0601 /* Unknown magic */ |
| .word 0x3a726556 /* "Ver:" */ |
| .word 0x31373030 /* "0071" */ |
| .word 0 /* First CRC32 */ |
| .word 0 /* Unknown - always 0 */ |
| .word 0 /* Second CRC32 */ |
| .word 0 /* length of firmware file */ |
| |
| #ifdef LOGIK_DAX |
| /* Some original firmwares have 0x40 bytes of zeroes here - we |
| don't know why, but err on the side of caution and include it |
| here. */ |
| .space 0x40 |
| #endif |
| #endif |
| |
| start_loc: |
| |
| #ifdef BOOTLOADER |
| |
| /* |
| If we are appended to the OF (i.e. dual-booting), do a simple GPIO |
| button check, and branch to the OF's entry point (saved by mktccboot) |
| if not active |
| */ |
| |
| #ifdef TCCBOOT |
| mov r0, #0x80000000 |
| #ifdef LOGIK_DAX |
| ldr r0, [r0, #0x300] /* Hold button is GPIO A, pin 0x2 */ |
| tst r0, #0x2 |
| #elif defined(SANSA_M200) |
| ldr r0, [r0, #0x310] /* Hold button is GPIO B, pin 0x200 */ |
| tst r0, #0x200 |
| #else |
| #error No bootup key detection implemented for this target |
| #endif |
| |
| ldrne pc, [pc, #-28] /* Jump to OF if HOLD button not pressed */ |
| #endif /* TCCBOOT */ |
| |
| /* We are now definitely executing the bootloader, so we relocate to the |
| linked address (see boot.lds) - 1MB from the end of DRAM. |
| */ |
| |
| #ifdef TCCBOOT |
| ldr r0, [pc, #-28] /* mktccboot fills in the load address */ |
| #else |
| mov r0, #0x20000000 /* Otherwise, load address is the start of DRAM */ |
| #endif |
| mov r1, #0x20000000 /* Destination: 1MB from end of DRAM */ |
| add r1, r1, #((MEM - 1) * 0x100000) |
| |
| ldr r2, =_dataend |
| 1: |
| cmp r2, r1 |
| ldrhi r3, [r0], #4 |
| strhi r3, [r1], #4 |
| bhi 1b |
| |
| ldr pc, =copied_start /* jump to the relocated start_loc: */ |
| copied_start: |
| #endif /* BOOTLOADER */ |
| |
| /* Set up stack for IRQ mode */ |
| mov r0,#0xd2 |
| msr cpsr, r0 |
| ldr sp, =irq_stack |
| |
| /* Set up stack for FIQ mode */ |
| mov r0,#0xd1 |
| msr cpsr, r0 |
| ldr sp, =fiq_stack |
| |
| /* Let abort and undefined modes use IRQ stack */ |
| mov r0,#0xd7 |
| msr cpsr, r0 |
| ldr sp, =irq_stack |
| mov r0,#0xdb |
| msr cpsr, r0 |
| ldr sp, =irq_stack |
| |
| /* Switch to supervisor mode */ |
| mov r0,#0xd3 |
| msr cpsr, r0 |
| ldr sp, =stackend |
| |
| /* Copy exception handler code to address 0 */ |
| mov r2, #0x0 |
| ldr r3, =vectors_start |
| ldr r4, =vectors_end |
| 1: |
| cmp r4, r3 |
| ldrhi r5, [r3], #4 |
| strhi r5, [r2], #4 |
| bhi 1b |
| |
| /* 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 |
| mov r3, sp |
| ldr r2, =stackbegin |
| ldr r4, =0xdeadbeef |
| 1: |
| cmp r3, r2 |
| strhi r4, [r2], #4 |
| bhi 1b |
| |
| bl main |
| /* main() should never return */ |
| |
| /* Exception handlers. Will be copied to address 0 after memory remapping */ |
| vectors_start: |
| 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 |
| vectors_end: |
| |
| .text |
| |
| /* 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 |
| |
| irq_handler: |
| stmfd sp!, {r0-r3, r12, lr} |
| bl irq |
| ldmfd sp!, {r0-r3, r12, lr} |
| subs pc, lr, #4 |
| |
| /* Align stacks to cache line boundary */ |
| .balign 16 |
| |
| /* 256 words of IRQ stack */ |
| .space 256*4 |
| irq_stack: |
| |
| /* 256 words of FIQ stack */ |
| .space 256*4 |
| fiq_stack: |
| |