u-boot/arch/arm/cpu/arm720t/start.S

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2002-11-03 00:38:21 +00:00
/*
* armboot - Startup Code for ARM720 CPU-core
*
* Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
* Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
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*
* 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
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* 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 <asm-offsets.h>
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#include <config.h>
#include <version.h>
#include <asm/hardware.h>
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/*
*************************************************************************
*
* Jump vector table as in table 3.1 in [1]
*
*************************************************************************
*/
.globl _start
_start: b reset
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ldr pc, _undefined_instruction
ldr pc, _software_interrupt
ldr pc, _prefetch_abort
ldr pc, _data_abort
#ifdef CONFIG_LPC2292
.word 0xB4405F76 /* 2's complement of the checksum of the vectors */
#else
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ldr pc, _not_used
#endif
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ldr pc, _irq
ldr pc, _fiq
_undefined_instruction: .word undefined_instruction
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_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
.balignl 16,0xdeadbeef
/*
*************************************************************************
*
* Startup Code (reset vector)
*
* do important init only if we don't start from RAM!
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* relocate armboot to ram
* setup stack
* jump to second stage
*
*************************************************************************
*/
.globl _TEXT_BASE
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_TEXT_BASE:
.word CONFIG_SYS_TEXT_BASE
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/*
* These are defined in the board-specific linker script.
* Subtracting _start from them lets the linker put their
* relative position in the executable instead of leaving
* them null.
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*/
.globl _bss_start_ofs
_bss_start_ofs:
.word __bss_start - _start
.globl _bss_end_ofs
_bss_end_ofs:
.word __bss_end__ - _start
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.globl _end_ofs
_end_ofs:
.word _end - _start
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#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
/* IRQ stack memory (calculated at run-time) + 8 bytes */
.globl IRQ_STACK_START_IN
IRQ_STACK_START_IN:
.word 0x0badc0de
/*
* 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
/*
* we do sys-critical inits only at reboot,
* not when booting from ram!
*/
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
bl cpu_init_crit
#endif
#ifdef CONFIG_LPC2292
bl lowlevel_init
#endif
/* Set stackpointer in internal RAM to call board_init_f */
call_board_init_f:
ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
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 */
/* Set up the stack */
stack_setup:
mov sp, r4
adr r0, _start
cmp r0, r6
beq clear_bss /* skip relocation */
mov r1, r6 /* r1 <- scratch for copy_loop */
ldr r3, _bss_start_ofs
add r2, r0, r3 /* r2 <- source end address */
copy_loop:
ldmia r0!, {r9-r10} /* copy from source address [r0] */
stmia r1!, {r9-r10} /* copy to target address [r1] */
cmp r0, r2 /* until source end address [r2] */
blo copy_loop
#ifndef CONFIG_SPL_BUILD
/*
* fix .rel.dyn relocations
*/
ldr r0, _TEXT_BASE /* r0 <- Text base */
sub r9, r6, r0 /* r9 <- relocation offset */
ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */
add r10, r10, r0 /* r10 <- sym table in FLASH */
ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */
add r2, r2, r0 /* r2 <- rel dyn start in FLASH */
ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */
add r3, r3, r0 /* r3 <- rel dyn end in FLASH */
fixloop:
ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */
add r0, r0, r9 /* r0 <- location to fix up in RAM */
ldr r1, [r2, #4]
and r7, r1, #0xff
cmp r7, #23 /* relative fixup? */
beq fixrel
cmp r7, #2 /* absolute fixup? */
beq fixabs
/* ignore unknown type of fixup */
b fixnext
fixabs:
/* absolute fix: set location to (offset) symbol value */
mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */
add r1, r10, r1 /* r1 <- address of symbol in table */
ldr r1, [r1, #4] /* r1 <- symbol value */
add r1, r1, r9 /* r1 <- relocated sym addr */
b fixnext
fixrel:
/* relative fix: increase location by offset */
ldr r1, [r0]
add r1, r1, r9
fixnext:
str r1, [r0]
add r2, r2, #8 /* each rel.dyn entry is 8 bytes */
cmp r2, r3
blo fixloop
#endif
clear_bss:
#ifndef CONFIG_SPL_BUILD
ldr r0, _bss_start_ofs
ldr r1, _bss_end_ofs
mov r4, r6 /* reloc addr */
add r0, r0, r4
add r1, r1, r4
mov r2, #0x00000000 /* clear */
clbss_l:cmp r0, r1 /* clear loop... */
bhs clbss_e /* if reached end of bss, exit */
str r2, [r0]
add r0, r0, #4
b clbss_l
clbss_e:
bl coloured_LED_init
bl red_led_on
#endif
/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
ldr r0, _board_init_r_ofs
adr r1, _start
add lr, r0, r1
add lr, lr, r9
/* setup parameters for board_init_r */
mov r0, r5 /* gd_t */
mov r1, r6 /* dest_addr */
/* jump to it ... */
mov pc, lr
_board_init_r_ofs:
.word board_init_r - _start
_rel_dyn_start_ofs:
.word __rel_dyn_start - _start
_rel_dyn_end_ofs:
.word __rel_dyn_end - _start
_dynsym_start_ofs:
.word __dynsym_start - _start
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/*
*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************
*/
#if defined(CONFIG_LPC2292)
PLLCFG_ADR: .word PLLCFG
PLLFEED_ADR: .word PLLFEED
PLLCON_ADR: .word PLLCON
PLLSTAT_ADR: .word PLLSTAT
VPBDIV_ADR: .word VPBDIV
MEMMAP_ADR: .word MEMMAP
#endif
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cpu_init_crit:
#if defined(CONFIG_NETARM)
/*
* prior to software reset : need to set pin PORTC4 to be *HRESET
*/
ldr r0, =NETARM_GEN_MODULE_BASE
ldr r1, =(NETARM_GEN_PORT_MODE(0x10) | \
NETARM_GEN_PORT_DIR(0x10))
str r1, [r0, #+NETARM_GEN_PORTC]
/*
* software reset : see HW Ref. Guide 8.2.4 : Software Service register
* for an explanation of this process
*/
ldr r0, =NETARM_GEN_MODULE_BASE
ldr r1, =NETARM_GEN_SW_SVC_RESETA
str r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
ldr r1, =NETARM_GEN_SW_SVC_RESETB
str r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
ldr r1, =NETARM_GEN_SW_SVC_RESETA
str r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
ldr r1, =NETARM_GEN_SW_SVC_RESETB
str r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
/*
* setup PLL and System Config
*/
ldr r0, =NETARM_GEN_MODULE_BASE
ldr r1, =( NETARM_GEN_SYS_CFG_LENDIAN | \
NETARM_GEN_SYS_CFG_BUSFULL | \
NETARM_GEN_SYS_CFG_USER_EN | \
NETARM_GEN_SYS_CFG_ALIGN_ABORT | \
NETARM_GEN_SYS_CFG_BUSARB_INT | \
NETARM_GEN_SYS_CFG_BUSMON_EN )
str r1, [r0, #+NETARM_GEN_SYSTEM_CONTROL]
#ifndef CONFIG_NETARM_PLL_BYPASS
ldr r1, =( NETARM_GEN_PLL_CTL_PLLCNT(NETARM_PLL_COUNT_VAL) | \
NETARM_GEN_PLL_CTL_POLTST_DEF | \
NETARM_GEN_PLL_CTL_INDIV(1) | \
NETARM_GEN_PLL_CTL_ICP_DEF | \
NETARM_GEN_PLL_CTL_OUTDIV(2) )
str r1, [r0, #+NETARM_GEN_PLL_CONTROL]
#endif
/*
* mask all IRQs by clearing all bits in the INTMRs
*/
mov r1, #0
ldr r0, =NETARM_GEN_MODULE_BASE
str r1, [r0, #+NETARM_GEN_INTR_ENABLE]
#elif defined(CONFIG_S3C4510B)
/*
* Mask off all IRQ sources
*/
ldr r1, =REG_INTMASK
ldr r0, =0x3FFFFF
str r0, [r1]
/*
* Disable Cache
*/
ldr r0, =REG_SYSCFG
ldr r1, =0x83ffffa0 /* cache-disabled */
str r1, [r0]
#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
/* No specific initialisation for IntegratorAP/CM720T as yet */
#elif defined(CONFIG_LPC2292)
/* Set-up PLL */
mov r3, #0xAA
mov r4, #0x55
/* First disconnect and disable the PLL */
ldr r0, PLLCON_ADR
mov r1, #0x00
str r1, [r0]
ldr r0, PLLFEED_ADR /* start feed sequence */
str r3, [r0]
str r4, [r0] /* feed sequence done */
/* Set new M and P values */
ldr r0, PLLCFG_ADR
mov r1, #0x23 /* M=4 and P=2 */
str r1, [r0]
ldr r0, PLLFEED_ADR /* start feed sequence */
str r3, [r0]
str r4, [r0] /* feed sequence done */
/* Then enable the PLL */
ldr r0, PLLCON_ADR
mov r1, #0x01 /* PLL enable bit */
str r1, [r0]
ldr r0, PLLFEED_ADR /* start feed sequence */
str r3, [r0]
str r4, [r0] /* feed sequence done */
/* Wait for the lock */
ldr r0, PLLSTAT_ADR
mov r1, #0x400 /* lock bit */
lock_loop:
ldr r2, [r0]
and r2, r1, r2
cmp r2, #0
beq lock_loop
/* And finally connect the PLL */
ldr r0, PLLCON_ADR
mov r1, #0x03 /* PLL enable bit and connect bit */
str r1, [r0]
ldr r0, PLLFEED_ADR /* start feed sequence */
str r3, [r0]
str r4, [r0] /* feed sequence done */
/* Set-up VPBDIV register */
ldr r0, VPBDIV_ADR
mov r1, #0x01 /* VPB clock is same as process clock */
str r1, [r0]
#else
#error No cpu_init_crit() defined for current CPU type
#endif
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#ifdef CONFIG_ARM7_REVD
/* set clock speed */
/* !!! we run @ 36 MHz due to a hardware flaw in Rev. D processors */
/* !!! not doing DRAM refresh properly! */
ldr r0, SYSCON3
ldr r1, [r0]
bic r1, r1, #CLKCTL
orr r1, r1, #CLKCTL_36
str r1, [r0]
#endif
#ifndef CONFIG_LPC2292
mov ip, lr
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/*
* before relocating, we have to setup RAM timing
* because memory timing is board-dependent, you will
* find a lowlevel_init.S in your board directory.
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*/
bl lowlevel_init
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mov lr, ip
#endif
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mov pc, lr
/*
*************************************************************************
*
* 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
#define I_BIT 0x80
/*
* use bad_save_user_regs for abort/prefetch/undef/swi ...
* use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
*/
.macro bad_save_user_regs
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} @ Calling r0-r12
add r8, sp, #S_PC
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ldr r2, IRQ_STACK_START_IN
ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0
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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
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mov r0, sp
.endm
.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
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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
ldr r13, IRQ_STACK_START_IN @ setup our mode stack
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str lr, [r13] @ save caller lr / spsr
mrs lr, spsr
str lr, [r13, #4]
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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
/*
* exception handlers
*/
.align 5
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undefined_instruction:
get_bad_stack
bad_save_user_regs
bl do_undefined_instruction
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.align 5
software_interrupt:
get_bad_stack
bad_save_user_regs
bl do_software_interrupt
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.align 5
prefetch_abort:
get_bad_stack
bad_save_user_regs
bl do_prefetch_abort
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.align 5
data_abort:
get_bad_stack
bad_save_user_regs
bl do_data_abort
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.align 5
not_used:
get_bad_stack
bad_save_user_regs
bl do_not_used
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#ifdef CONFIG_USE_IRQ
.align 5
irq:
get_irq_stack
irq_save_user_regs
bl do_irq
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irq_restore_user_regs
.align 5
fiq:
get_fiq_stack
/* someone ought to write a more effiction fiq_save_user_regs */
irq_save_user_regs
bl do_fiq
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irq_restore_user_regs
#else
.align 5
irq:
get_bad_stack
bad_save_user_regs
bl do_irq
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.align 5
fiq:
get_bad_stack
bad_save_user_regs
bl do_fiq
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#endif
#if defined(CONFIG_NETARM)
.align 5
.globl reset_cpu
reset_cpu:
ldr r1, =NETARM_MEM_MODULE_BASE
ldr r0, [r1, #+NETARM_MEM_CS0_BASE_ADDR]
ldr r1, =0xFFFFF000
and r0, r1, r0
ldr r1, =(relocate-CONFIG_SYS_TEXT_BASE)
add r0, r1, r0
ldr r4, =NETARM_GEN_MODULE_BASE
ldr r1, =NETARM_GEN_SW_SVC_RESETA
str r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
ldr r1, =NETARM_GEN_SW_SVC_RESETB
str r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
ldr r1, =NETARM_GEN_SW_SVC_RESETA
str r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
ldr r1, =NETARM_GEN_SW_SVC_RESETB
str r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
mov pc, r0
#elif defined(CONFIG_S3C4510B)
/* Nothing done here as reseting the CPU is board specific, depending
* on external peripherals such as watchdog timers, etc. */
#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
/* No specific reset actions for IntegratorAP/CM720T as yet */
#elif defined(CONFIG_LPC2292)
.align 5
.globl reset_cpu
reset_cpu:
mov pc, r0
#else
#error No reset_cpu() defined for current CPU type
#endif