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u-boot-brain/arch/arm/cpu/pxa/start.S
Marek Vasut 2cad92fd67 PXA: Fix reloc, Push lowlevel init into C code 
Firstly, this fixes relocation issues. I had to use part of Dcache as RAM for a
while. I also moved around the lowlevel init code. It turned out so most of the
lowlevel init code ended in cpu.c (and eventually was rewritten into C).

This will also allow easier operation with FDT, multi-CPU-model support etc. in
later releases.

NOTE: This breaks most of the PXA boards (actually, the reloc stuff did already,
this only finishes the doom).

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
2010-10-19 23:04:35 +02:00

624 lines
14 KiB
ArmAsm
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/*
* armboot - Startup Code for XScale
*
* Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
* Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
* Copyright (C) 2000 Wolfgang Denk <wd@denx.de>
* Copyright (C) 2001 Alex Zuepke <azu@sysgo.de>
* Copyright (C) 2002 Kyle Harris <kharris@nexus-tech.net>
* Copyright (C) 2003 Robert Schwebel <r.schwebel@pengutronix.de>
* Copyright (C) 2003 Kai-Uwe Bloem <kai-uwe.bloem@auerswald.de>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <config.h>
#include <version.h>
#include <asm/arch/pxa-regs.h>
#include <asm/arch/macro.h>
/* takes care the CP15 update has taken place */
.macro CPWAIT reg
mrc p15,0,\reg,c2,c0,0
mov \reg,\reg
sub pc,pc,#4
.endm
.globl _start
_start: b reset
#ifdef CONFIG_PRELOADER
ldr pc, _hang
ldr pc, _hang
ldr pc, _hang
ldr pc, _hang
ldr pc, _hang
ldr pc, _hang
ldr pc, _hang
_hang:
.word do_hang
.word 0x12345678
.word 0x12345678
.word 0x12345678
.word 0x12345678
.word 0x12345678
.word 0x12345678
.word 0x12345678 /* now 16*4=64 */
#else
ldr pc, _undefined_instruction
ldr pc, _software_interrupt
ldr pc, _prefetch_abort
ldr pc, _data_abort
ldr pc, _not_used
ldr pc, _irq
ldr pc, _fiq
_undefined_instruction: .word undefined_instruction
_software_interrupt: .word software_interrupt
_prefetch_abort: .word prefetch_abort
_data_abort: .word data_abort
_not_used: .word not_used
_irq: .word irq
_fiq: .word fiq
#endif /* CONFIG_PRELOADER */
.balignl 16,0xdeadbeef
/*
* Startup Code (reset vector)
*
* do important init only if we don't start from RAM!
* - relocate armboot to RAM
* - setup stack
* - jump to second stage
*/
.globl _TEXT_BASE
_TEXT_BASE:
.word CONFIG_SYS_TEXT_BASE
.globl _armboot_start
_armboot_start:
.word _start
/*
* These are defined in the board-specific linker script.
*/
.globl _bss_start
_bss_start:
.word __bss_start
.globl _bss_end
_bss_end:
.word _end
#ifdef CONFIG_USE_IRQ
/* IRQ stack memory (calculated at run-time) */
.globl IRQ_STACK_START
IRQ_STACK_START:
.word 0x0badc0de
/* IRQ stack memory (calculated at run-time) */
.globl FIQ_STACK_START
FIQ_STACK_START:
.word 0x0badc0de
#endif /* CONFIG_USE_IRQ */
#ifndef CONFIG_PRELOADER
/* IRQ stack memory (calculated at run-time) + 8 bytes */
.globl IRQ_STACK_START_IN
IRQ_STACK_START_IN:
.word 0x0badc0de
.globl _datarel_start
_datarel_start:
.word __datarel_start
.globl _datarelrolocal_start
_datarelrolocal_start:
.word __datarelrolocal_start
.globl _datarellocal_start
_datarellocal_start:
.word __datarellocal_start
.globl _datarelro_start
_datarelro_start:
.word __datarelro_start
.globl _got_start
_got_start:
.word __got_start
.globl _got_end
_got_end:
.word __got_end
/*
* the actual reset code
*/
reset:
/*
* set the cpu to SVC32 mode
*/
mrs r0,cpsr
bic r0,r0,#0x1f
orr r0,r0,#0xd3
msr cpsr,r0
/*
* Enable MMU to use DCache as DRAM
*/
/* Domain access -- enable for all CPs */
ldr r0, =0x0000ffff
mcr p15, 0, r0, c3, c0, 0
/* Point TTBR to MMU table */
ldr r0, =mmu_table
adr r2, _start
orr r0, r2
mcr p15, 0, r0, c2, c0, 0
/* !!! Hereby, check if the code is running from SRAM !!! */
/* If the code is running from SRAM, alias SRAM to 0x0 to simulate NOR. The code
* is linked to 0x0 too, so this makes things easier. */
cmp r2, #0x5c000000
ldreq r1, [r0]
orreq r1, r2
streq r1, [r0]
/* Kick in MMU, ICache, DCache, BTB */
mrc p15, 0, r0, c1, c0, 0
bic r0, #0x1b00
bic r0, #0x0087
orr r0, #0x1800
orr r0, #0x0005
mcr p15, 0, r0, c1, c0, 0
CPWAIT r0
/* Unlock Icache, Dcache */
mcr p15, 0, r0, c9, c1, 1
mcr p15, 0, r0, c9, c2, 1
/* Flush Icache, Dcache, BTB */
mcr p15, 0, r0, c7, c7, 0
/* Unlock I-TLB, D-TLB */
mcr p15, 0, r0, c10, c4, 1
mcr p15, 0, r0, c10, c8, 1
/* Flush TLB */
mcr p15, 0, r0, c8, c7, 0
/* Allocate 4096 bytes of Dcache as RAM */
/* Drain pending loads and stores */
mcr p15, 0, r0, c7, c10, 4
mov r4, #0x00
mov r5, #0x00
mov r2, #0x01
mcr p15, 0, r0, c9, c2, 0
CPWAIT r0
/* 128 lines reserved (128 x 32bytes = 4096 bytes total) */
mov r0, #128
mov r1, #0xa0000000
alloc:
mcr p15, 0, r1, c7, c2, 5
/* Drain pending loads and stores */
mcr p15, 0, r0, c7, c10, 4
strd r4, [r1], #8
strd r4, [r1], #8
strd r4, [r1], #8
strd r4, [r1], #8
subs r0, #0x01
bne alloc
/* Drain pending loads and stores */
mcr p15, 0, r0, c7, c10, 4
mov r2, #0x00
mcr p15, 0, r2, c9, c2, 0
CPWAIT r0
/* Jump to 0x0 ( + offset) if running from SRAM */
adr r0, zerojmp
bic r0, #0x5c000000
mov pc, r0
zerojmp:
/* Set stackpointer in internal RAM to call board_init_f */
call_board_init_f:
ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
ldr r0,=0x00000000
bl board_init_f
/*------------------------------------------------------------------------------*/
/*
* void relocate_code (addr_sp, gd, addr_moni)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*
*/
.globl relocate_code
relocate_code:
mov r4, r0 /* save addr_sp */
mov r5, r1 /* save addr of gd */
mov r6, r2 /* save addr of destination */
mov r7, r2 /* save addr of destination */
/* Set up the stack */
stack_setup:
mov sp, r4
adr r0, _start
ldr r2, _TEXT_BASE
ldr r3, _bss_start
sub r2, r3, r2 /* r2 <- size of armboot */
add r2, r0, r2 /* r2 <- source end address */
cmp r0, r6
beq clear_bss
#ifndef CONFIG_SKIP_RELOCATE_UBOOT
stmfd sp!, {r0-r12}
copy_loop:
ldmia r0!, {r3-r5, r7-r11} /* copy from source address [r0] */
stmia r6!, {r3-r5, r7-r11} /* copy to target address [r1] */
cmp r0, r2 /* until source end address [r2] */
blo copy_loop
ldmfd sp!, {r0-r12}
#ifndef CONFIG_PRELOADER
/* fix got entries */
ldr r1, _TEXT_BASE /* Text base */
mov r0, r7 /* reloc addr */
ldr r2, _got_start /* addr in Flash */
ldr r3, _got_end /* addr in Flash */
sub r3, r3, r1
add r3, r3, r0
sub r2, r2, r1
add r2, r2, r0
fixloop:
ldr r4, [r2]
sub r4, r4, r1
add r4, r4, r0
str r4, [r2]
add r2, r2, #4
cmp r2, r3
bne fixloop
#endif
#endif /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
clear_bss:
#ifndef CONFIG_PRELOADER
ldr r0, _bss_start
ldr r1, _bss_end
ldr r3, _TEXT_BASE /* Text base */
mov r4, r7 /* reloc addr */
sub r0, r0, r3
add r0, r0, r4
sub r1, r1, r3
add r1, r1, r4
mov r2, #0x00000000 /* clear */
clbss_l:str r2, [r0] /* clear loop... */
add r0, r0, #4
cmp r0, r1
bne clbss_l
#endif
/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
#ifdef CONFIG_ONENAND_IPL
ldr pc, _start_oneboot
_start_oneboot: .word start_oneboot
#else
ldr r0, _TEXT_BASE
ldr r2, _board_init_r
sub r2, r2, r0
add r2, r2, r7 /* position from board_init_r in RAM */
/* setup parameters for board_init_r */
mov r0, r5 /* gd_t */
mov r1, r7 /* dest_addr */
/* jump to it ... */
mov lr, r2
mov pc, lr
_board_init_r: .word board_init_r
#endif
#else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
/****************************************************************************/
/* */
/* the actual reset code for OneNAND IPL */
/* */
/****************************************************************************/
#ifndef CONFIG_PXA27X
#error OneNAND IPL is not supported on PXA25x and 26x due to lack of SRAM
#endif
reset:
/* Set CPU to SVC32 mode */
mrs r0,cpsr
bic r0,r0,#0x1f
orr r0,r0,#0x13
msr cpsr,r0
/* Point stack at the end of SRAM and leave 32 words for abort-stack */
ldr sp, =0x5c03ff80
/* Start OneNAND IPL */
ldr pc, =start_oneboot
#endif /* #if !defined(CONFIG_ONENAND_IPL) */
#ifndef CONFIG_PRELOADER
/****************************************************************************/
/* */
/* Interrupt handling */
/* */
/****************************************************************************/
/* IRQ stack frame */
#define S_FRAME_SIZE 72
#define S_OLD_R0 68
#define S_PSR 64
#define S_PC 60
#define S_LR 56
#define S_SP 52
#define S_IP 48
#define S_FP 44
#define S_R10 40
#define S_R9 36
#define S_R8 32
#define S_R7 28
#define S_R6 24
#define S_R5 20
#define S_R4 16
#define S_R3 12
#define S_R2 8
#define S_R1 4
#define S_R0 0
#define MODE_SVC 0x13
/* use bad_save_user_regs for abort/prefetch/undef/swi ... */
.macro bad_save_user_regs
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} /* Calling r0-r12 */
add r8, sp, #S_PC
#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
ldr r2, _armboot_start
sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
#else
ldr r2, IRQ_STACK_START_IN
#endif
ldmia r2, {r2 - r4} /* get pc, cpsr, old_r0 */
add r0, sp, #S_FRAME_SIZE /* restore sp_SVC */
add r5, sp, #S_SP
mov r1, lr
stmia r5, {r0 - r4} /* save sp_SVC, lr_SVC, pc, cpsr, old_r */
mov r0, sp
.endm
/* use irq_save_user_regs / irq_restore_user_regs for */
/* IRQ/FIQ handling */
.macro irq_save_user_regs
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} /* Calling r0-r12 */
add r8, sp, #S_PC
stmdb r8, {sp, lr}^ /* Calling SP, LR */
str lr, [r8, #0] /* Save calling PC */
mrs r6, spsr
str r6, [r8, #4] /* Save CPSR */
str r0, [r8, #8] /* Save OLD_R0 */
mov r0, sp
.endm
.macro irq_restore_user_regs
ldmia sp, {r0 - lr}^ @ Calling r0 - lr
mov r0, r0
ldr lr, [sp, #S_PC] @ Get PC
add sp, sp, #S_FRAME_SIZE
subs pc, lr, #4 @ return & move spsr_svc into cpsr
.endm
.macro get_bad_stack
#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
ldr r13, _armboot_start @ setup our mode stack
sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
#else
ldr r13, IRQ_STACK_START_IN @ setup our mode stack
#endif
str lr, [r13] @ save caller lr / spsr
mrs lr, spsr
str lr, [r13, #4]
mov r13, #MODE_SVC @ prepare SVC-Mode
msr spsr_c, r13
mov lr, pc
movs pc, lr
.endm
.macro get_irq_stack @ setup IRQ stack
ldr sp, IRQ_STACK_START
.endm
.macro get_fiq_stack @ setup FIQ stack
ldr sp, FIQ_STACK_START
.endm
#endif /* CONFIG_PRELOADER */
/****************************************************************************/
/* */
/* exception handlers */
/* */
/****************************************************************************/
#ifdef CONFIG_PRELOADER
.align 5
do_hang:
ldr sp, _TEXT_BASE /* use 32 words abort stack */
bl hang /* hang and never return */
#else /* !CONFIG_PRELOADER */
.align 5
undefined_instruction:
get_bad_stack
bad_save_user_regs
bl do_undefined_instruction
.align 5
software_interrupt:
get_bad_stack
bad_save_user_regs
bl do_software_interrupt
.align 5
prefetch_abort:
get_bad_stack
bad_save_user_regs
bl do_prefetch_abort
.align 5
data_abort:
get_bad_stack
bad_save_user_regs
bl do_data_abort
.align 5
not_used:
get_bad_stack
bad_save_user_regs
bl do_not_used
#ifdef CONFIG_USE_IRQ
.align 5
irq:
get_irq_stack
irq_save_user_regs
bl do_irq
irq_restore_user_regs
.align 5
fiq:
get_fiq_stack
irq_save_user_regs /* someone ought to write a more */
bl do_fiq /* effiction fiq_save_user_regs */
irq_restore_user_regs
#else /* !CONFIG_USE_IRQ */
.align 5
irq:
get_bad_stack
bad_save_user_regs
bl do_irq
.align 5
fiq:
get_bad_stack
bad_save_user_regs
bl do_fiq
#endif /* CONFIG_PRELOADER */
#endif /* CONFIG_USE_IRQ */
/****************************************************************************/
/* */
/* Reset function: the PXA250 doesn't have a reset function, so we have to */
/* perform a watchdog timeout for a soft reset. */
/* */
/****************************************************************************/
/* Operating System Timer */
OSTIMER_BASE: .word 0x40a00000
#define OSMR3 0x0C
#define OSCR 0x10
#define OWER 0x18
#define OIER 0x1C
.align 5
.globl reset_cpu
/* FIXME: this code is PXA250 specific. How is this handled on */
/* other XScale processors? */
reset_cpu:
/* We set OWE:WME (watchdog enable) and wait until timeout happens */
ldr r0, OSTIMER_BASE
ldr r1, [r0, #OWER]
orr r1, r1, #0x0001 /* bit0: WME */
str r1, [r0, #OWER]
/* OS timer does only wrap every 1165 seconds, so we have to set */
/* the match register as well. */
ldr r1, [r0, #OSCR] /* read OS timer */
add r1, r1, #0x800 /* let OSMR3 match after */
add r1, r1, #0x800 /* 4096*(1/3.6864MHz)=1ms */
str r1, [r0, #OSMR3]
reset_endless:
b reset_endless
#ifndef CONFIG_PRELOADER
.section .mmudata, "a"
.align 14
.globl mmu_table
mmu_table:
/* 0x00000000 - 0xa0000000 : 1:1, uncached mapping */
.set __base, 0
.rept 0xa00
.word (__base << 20) | 0xc12
.set __base, __base + 1
.endr
/* 0xa0000000 - 0xa0100000 : 1:1, cached mapping */
.word (0xa00 << 20) | 0x1c1e
.set __base, 0xa01
.rept 0x1000 - 0xa01
.word (__base << 20) | 0xc12
.set __base, __base + 1
.endr
#endif
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