u-boot/arch/arm/cpu/arm720t/start.S
Allen Martin c037c93bf9 ARM: add tegra20 support to arm720t
Add support for tegra20 arm7 boot processor.  This processor is used
to power on the Cortex A9 and transfer control to it.  In tegra this
processor is an ARM7TDMI not an ARM720T, but since we don't use cache
it was easier to just reuse the ARM720T code as the processors are
otherwise identical except for cache and MMU.

Signed-off-by: Allen Martin <amartin@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>
2012-09-01 14:58:22 +02:00

648 lines
15 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 <asm-offsets.h>
#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
#ifdef CONFIG_SPL_BUILD
_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
_pad: .word 0x12345678 /* now 16*4=64 */
#else
_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
_pad: .word 0x12345678 /* now 16*4=64 */
#endif /* CONFIG_SPL_BUILD */
.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:
#ifdef CONFIG_SPL_BUILD
.word CONFIG_SPL_TEXT_BASE
#else
.word CONFIG_SYS_TEXT_BASE
#endif
/*
* 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.
*/
.globl _bss_start_ofs
_bss_start_ofs:
.word __bss_start - _start
.globl _bss_end_ofs
_bss_end_ofs:
.word __bss_end__ - _start
.globl _end_ofs
_end_ofs:
.word _end - _start
#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
moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */
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
/*
*************************************************************************
*
* 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
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]
#elif defined(CONFIG_TEGRA)
/* No cpu_init_crit for tegra 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
#if !defined(CONFIG_LPC2292) && !defined(CONFIG_TEGRA)
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
#ifndef CONFIG_SPL_BUILD
/*
*************************************************************************
*
* 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, IRQ_STACK_START_IN
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, IRQ_STACK_START_IN @ setup our mode 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
#endif /* CONFIG_SPL_BUILD */
#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
#elif defined(CONFIG_TEGRA)
/* No specific reset actions for tegra as yet */
#else
#error No reset_cpu() defined for current CPU type
#endif