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uboot-1.1.4-kirkwood/cpu/arm720t/start.S
2024-01-07 23:57:24 +01:00

543 lines
12 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
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
.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
*
*************************************************************************
*/
_TEXT_BASE:
.word 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
/*
* 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
#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
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
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, #CFG_MALLOC_LEN /* malloc area */
sub r0, r0, #CFG_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 */
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
/*
*************************************************************************
*
* 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 */
#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 */
#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
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
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
ldr r2, _armboot_start
sub r2, r2, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
sub r2, r2, #(CFG_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
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
ldr r13, _armboot_start @ setup our mode stack
sub r13, r13, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
sub r13, r13, #(CFG_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
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 */
#else
#error No reset_cpu() defined for current CPU type
#endif