/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2002 by Linus Nielsen Feltzing * * 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: /* PortalPlayer 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 * */ #if CONFIG_CPU == PP5002 .equ PROC_ID, 0xc4000000 .equ COP_CTRL, 0xcf004058 .equ COP_STATUS, 0xcf004050 .equ IIS_CONFIG, 0xc0002500 .equ SLEEP, 0xca .equ WAKE, 0xce .equ SLEEPING, 0x4000 #else .equ PROC_ID, 0x60000000 .equ COP_CTRL, 0x60007004 .equ COP_STATUS, 0x60007004 .equ IIS_CONFIG, 0x70002800 .equ SLEEP, 0x80000000 .equ WAKE, 0x0 .equ SLEEPING, 0x80000000 .equ CACHE_CTRL, 0x6000c000 #endif msr cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ */ b pad_skip .space 50*4 /* (more than enough) space for exception vectors */ pad_skip: #ifdef SANSA_E200 /* On the Sansa, copying the vectors fails if the cache is initialised */ ldr r1, =CACHE_CTRL mov r2, #0x0 str r2, [r1] #endif /* We need to remap memory from wherever SDRAM is mapped natively, to base address 0, so we can put our exception vectors there. We don't want to do this remapping while executing from SDRAM, so we copy the remapping code to IRAM, then execute from there. Hence, the following code is compiled for address 0, but is currently executing at either 0x28000000 or 0x10000000, depending on chipset version. Do not use any absolute addresses until remapping has been done. */ ldr r1, =0x40000000 ldr r2, =remap_start ldr r3, =remap_end and r5, pc, #0xff000000 /* adjust for execute address */ orr r2, r2, r5 orr r3, r3, r5 /* copy the code to 0x40000000 */ 1: ldr r4, [r2], #4 str r4, [r1], #4 cmp r2, r3 ble 1b ldr r3, =0x3f84 /* r3 and r1 values here are magic, don't touch */ orr r3, r3, r5 /* adjust for execute address */ ldr r2, =0xf000f014 mov r1, #0x3a00 ldr r0, =0xf000f010 mov pc, #0x40000000 remap_start: str r1, [r0] str r3, [r2] ldr r0, L_post_remap mov pc, r0 L_post_remap: .word remap_end remap_end: /* After doing the remapping, send the COP to sleep. On wakeup it will go to cop_init */ /* Find out which processor we are */ ldr r0, =PROC_ID ldr r0, [r0] and r0, r0, #0xff cmp r0, #0x55 beq cpu_init /* put us (co-processor) to sleep */ ldr r4, =COP_CTRL mov r3, #SLEEP str r3, [r4] ldr pc, =cop_init cpu_init: /* Wait for COP to be sleeping */ ldr r4, =COP_STATUS 1: ldr r3, [r4] ands r3, r3, #SLEEPING beq 1b /* 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 /* 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 /* 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 /* 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 /* We'll load the banked FIQ mode registers with useful values here. These values will be used in the FIQ handler in pcm_playback.c */ ldr r12, =IIS_CONFIG ldr r11, =p /* 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 */ msr cpsr_c, #0xd3 ldr sp, =stackend bl main /* main() should never return */ cop_init: #if CONFIG_CPU != PP5002 /* COP: Invalidate cache */ ldr r0, =0xf000f044 ldr r1, [r0] orr r1, r1, #0x6 str r1, [r0] ldr r0, =0x6000c000 1: ldr r1, [r0] tst r1, #0x8000 bne 1b #endif /* Setup stack for COP */ ldr sp, =cop_stackend mov r3, sp ldr r2, =cop_stackbegin ldr r4, =0xdeadbeef 2: cmp r3, r2 strhi r4, [r2], #4 bhi 2b ldr sp, =cop_stackend /* Run cop_main() in apps/main.c */ bl cop_main /* 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 #ifndef 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 fiq_handler: @ Branch straight to FIQ handler in pcm_playback.c. This also handles the @ the correct return sequence. ldr pc, =fiq data_abort_handler: sub r0, lr, #8 mov r1, #2 b UIE irq_handler: #ifndef STUB stmfd sp!, {r0-r3, r12, lr} bl irq ldmfd sp!, {r0-r3, r12, lr} #endif subs pc, lr, #4 #ifdef STUB UIE: b UIE #endif /* 256 words of IRQ stack */ .space 256*4 irq_stack: /* 256 words of FIQ stack */ .space 256*4 fiq_stack: