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u-boot/arch/arm/lib/vectors.S
Andre Przywara cdaa633fcf arm/arm64: implement a boot header capability 
Some SPL loaders (like Allwinner's boot0, and Broadcom's boot0)
require a header before the actual U-Boot binary to both check its
validity and to find other data to load. Sometimes this header may
only be a few bytes of information, and sometimes this might simply
be space that needs to be reserved for a post-processing tool.

Introduce a config option to allow assembler preprocessor commands
to be inserted into the code at the appropriate location; typical
assembler preprocessor commands might be:
  .space 1000
  .word 0x12345678

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Steve Rae <srae@broadcom.com>
Commit Notes:
Please note that the current code:
  start.S (arm64) and
  vectors.S (arm)
already jumps over some portion of data already, so this option basically
just increases the size of this region (and the resulting binary).

For use with Allwinner's boot0 blob there is a tool called boot0img[1],
which fills the header to allow booting A64 based boards.
For the Pine64 we need a 1536 byte header (including the branch
instruction) at the moment, so we add this to the defconfig.

[1] https://github.com/apritzel/pine64/tree/master/tools
END
Reviewed-by: Tom Rini <trini@konsulko.com>
2016-06-06 13:39:19 -04:00

301 lines
6.3 KiB
ArmAsm
Raw Blame History

/*
* vectors - Generic ARM exception table code
*
* 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 Züpke <azu@sysgo.de>
* Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
* Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
* Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
* Copyright (c) 2002 Kyle Harris <kharris@nexus-tech.net>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
/*
*************************************************************************
*
* Symbol _start is referenced elsewhere, so make it global
*
*************************************************************************
*/
.globl _start
/*
*************************************************************************
*
* Vectors have their own section so linker script can map them easily
*
*************************************************************************
*/
.section ".vectors", "ax"
/*
*************************************************************************
*
* Exception vectors as described in ARM reference manuals
*
* Uses indirect branch to allow reaching handlers anywhere in memory.
*
*************************************************************************
*/
_start:
#ifdef CONFIG_SYS_DV_NOR_BOOT_CFG
.word CONFIG_SYS_DV_NOR_BOOT_CFG
#endif
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
#ifdef CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK
/*
* Various SoCs need something special and SoC-specific up front in
* order to boot, allow them to set that in their boot0.h file and then
* use it here.
*/
#include <asm/arch/boot0.h>
ARM_SOC_BOOT0_HOOK
#endif
/*
*************************************************************************
*
* Indirect vectors table
*
* Symbols referenced here must be defined somewhere else
*
*************************************************************************
*/
.globl _undefined_instruction
.globl _software_interrupt
.globl _prefetch_abort
.globl _data_abort
.globl _not_used
.globl _irq
.globl _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
/*
*************************************************************************
*
* Interrupt handling
*
*************************************************************************
*/
/* SPL interrupt handling: just hang */
#ifdef CONFIG_SPL_BUILD
.align 5
undefined_instruction:
software_interrupt:
prefetch_abort:
data_abort:
not_used:
irq:
fiq:
1:
bl 1b /* hang and never return */
#else /* !CONFIG_SPL_BUILD */
/* IRQ stack memory (calculated at run-time) + 8 bytes */
.globl IRQ_STACK_START_IN
IRQ_STACK_START_IN:
.word 0x0badc0de
#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 */
@
@ 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
@ carve out a frame on current user stack
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12
ldr r2, IRQ_STACK_START_IN
@ get values for "aborted" pc and cpsr (into parm regs)
ldmia r2, {r2 - r3}
add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack
add r5, sp, #S_SP
mov r1, lr
stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
mov r0, sp @ save current stack into r0 (param register)
.endm
.macro irq_save_user_regs
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} @ Calling r0-r12
@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
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 in position 0 of saved stack
mrs lr, spsr @ get the spsr
str lr, [r13, #4] @ save spsr in position 1 of saved stack
mov r13, #MODE_SVC @ prepare SVC-Mode
@ msr spsr_c, r13
msr spsr, r13 @ switch modes, make sure moves will execute
mov lr, pc @ capture return pc
movs pc, lr @ jump to next instruction & switch modes.
.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 /* CONFIG_USE_IRQ */
#endif /* CONFIG_SPL_BUILD */
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