u-boot-brain/arch/arm/cpu/arm720t/start.S
Heiko Schocher abef7b859d ARM: implement relocation for arm720t
Change the implementation for arm720t to relocate the code to
an arbitrary address in RAM.

Portions of this work were supported by funding from
the CE Linux Forum.

Signed-off-by: Heiko Schocher <hs@denx.de>
2010-09-19 19:29:56 +02:00

783 lines
18 KiB
ArmAsm

/*
* armboot - Startup Code for ARM720 CPU-core
*
* Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
* Copyright (c) 2002 Alex Züpke <azu@sysgo.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/hardware.h>
/*
*************************************************************************
*
* Jump vector table as in table 3.1 in [1]
*
*************************************************************************
*/
.globl _start
_start: b reset
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
ldr pc, _not_used
#endif
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
.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 TEXT_BASE
#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
.globl _armboot_start
_armboot_start:
.word _start
#endif
/*
* 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
#if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
/* 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
/*
* 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)
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
copy_loop:
ldmia r0!, {r9-r10} /* copy from source address [r0] */
stmia r6!, {r9-r10} /* copy to target address [r1] */
cmp r0, r2 /* until source end addreee [r2] */
ble copy_loop
#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
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, _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
#else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
/*
* the actual reset code
*/
reset:
/*
* set the cpu to SVC32 mode
*/
mrs r0,cpsr
bic r0,r0,#0x1f
orr r0,r0,#0x13
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
#ifndef CONFIG_SKIP_RELOCATE_UBOOT
relocate: /* relocate U-Boot to RAM */
adr r0, _start /* r0 <- current position of code */
ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
cmp r0, r1 /* don't reloc during debug */
beq stack_setup
#if TEXT_BASE
#ifndef CONFIG_LPC2292 /* already done in lowlevel_init */
ldr r2, =0x0 /* Relocate the exception vectors */
cmp r1, r2 /* and associated data to address */
ldmneia r0!, {r3-r10} /* 0x0. Do nothing if TEXT_BASE is */
stmneia r2!, {r3-r10} /* 0x0. Copy the first 15 words. */
ldmneia r0, {r3-r9}
stmneia r2, {r3-r9}
adrne r0, _start /* restore r0 */
#endif /* !CONFIG_LPC2292 */
#endif
ldr r2, _armboot_start
ldr r3, _bss_start
sub r2, r3, r2 /* r2 <- size of armboot */
add r2, r0, r2 /* r2 <- source end address */
copy_loop:
ldmia r0!, {r3-r10} /* copy from source address [r0] */
stmia r1!, {r3-r10} /* copy to target address [r1] */
cmp r0, r2 /* until source end addreee [r2] */
ble copy_loop
#endif /* CONFIG_SKIP_RELOCATE_UBOOT */
/* Set up the stack */
stack_setup:
ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc area */
sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo */
#ifdef CONFIG_USE_IRQ
sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
#endif
sub sp, r0, #12 /* leave 3 words for abort-stack */
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
clear_bss:
ldr r0, _bss_start /* find start of bss segment */
ldr r1, _bss_end /* stop here */
mov r2, #0x00000000 /* clear */
clbss_l:str r2, [r0] /* clear loop... */
add r0, r0, #4
cmp r0, r1
ble clbss_l
ldr pc, _start_armboot
_start_armboot: .word start_armboot
#endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
/*
*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************
*/
#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
/* Interupt-Controller base addresses */
INTMR1: .word 0x80000280 @ 32 bit size
INTMR2: .word 0x80001280 @ 16 bit size
INTMR3: .word 0x80002280 @ 8 bit size
/* SYSCONs */
SYSCON1: .word 0x80000100
SYSCON2: .word 0x80001100
SYSCON3: .word 0x80002200
#define CLKCTL 0x6 /* mask */
#define CLKCTL_18 0x0 /* 18.432 MHz */
#define CLKCTL_36 0x2 /* 36.864 MHz */
#define CLKCTL_49 0x4 /* 49.152 MHz */
#define CLKCTL_73 0x6 /* 73.728 MHz */
#elif 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
cpu_init_crit:
#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
/*
* mask all IRQs by clearing all bits in the INTMRs
*/
mov r1, #0x00
ldr r0, INTMR1
str r1, [r0]
ldr r0, INTMR2
str r1, [r0]
ldr r0, INTMR3
str r1, [r0]
/*
* flush v4 I/D caches
*/
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
/*
* disable MMU stuff and caches
*/
mrc p15,0,r0,c1,c0
bic r0, r0, #0x00002300 @ clear bits 13, 9:8 (--V- --RS)
bic r0, r0, #0x0000008f @ clear bits 7, 3:0 (B--- WCAM)
orr r0, r0, #0x00000002 @ set bit 2 (A) Align
mcr p15,0,r0,c1,c0
#elif 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
#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
/*
* 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.
*/
bl lowlevel_init
mov lr, ip
#endif
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
#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
.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
/*
* exception handlers
*/
.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
/* someone ought to write a more effiction fiq_save_user_regs */
irq_save_user_regs
bl do_fiq
irq_restore_user_regs
#else
.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
#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
.align 5
.globl reset_cpu
reset_cpu:
mov ip, #0
mcr p15, 0, ip, c7, c7, 0 @ invalidate cache
mcr p15, 0, ip, c8, c7, 0 @ flush TLB (v4)
mrc p15, 0, ip, c1, c0, 0 @ get ctrl register
bic ip, ip, #0x000f @ ............wcam
bic ip, ip, #0x2100 @ ..v....s........
mcr p15, 0, ip, c1, c0, 0 @ ctrl register
mov pc, r0
#elif 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-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