Dear Albert Aribaud,
On 09.03.2014 17:18, Albert ARIBAUD wrote:
<snip>
diff --git a/arch/arm/lib/vectors.S b/arch/arm/lib/vectors.S new file mode 100644 index 0000000..1655d49 --- /dev/null +++ b/arch/arm/lib/vectors.S @@ -0,0 +1,304 @@ +/*
- 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+
- */
+/*
- 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", "x"
+/*
- 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
+#ifdef CONFIG_SPL_BUILD
+_start:
- ldr pc, _reset
- ldr pc, _hang
- ldr pc, _hang
- ldr pc, _hang
- ldr pc, _hang
- ldr pc, _hang
- ldr pc, _hang
- ldr pc, _hang
+#else
+_start:
- ldr pc, _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
+#endif
+/*
- Indirect vectors table
- Symbols referenced here must be defined somewhere else
- */
+_reset: .word reset
+#ifdef CONFIG_SPL_BUILD
+_hang: .word do_hang
+#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
+#endif
- .balignl 16,0xdeadbeef
+/*
- Interrupt handling
- */
+/* IRQ stack memory (calculated at run-time) + 8 bytes */ +.globl IRQ_STACK_START_IN +IRQ_STACK_START_IN:
- .word 0x0badc0de
+#ifndef CONFIG_SPL_BUILD
+#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 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
+#endif /* CONFIG_SPL_BUILD */
+/*
- exception handlers
- */
+#ifdef CONFIG_SPL_BUILD
- .align 5
+do_hang: +1:
- bl 1b /* hang and never return */
+#else /* !CONFIG_SPL_BUILD */
- .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 */
this file is completely different for SPL and non-SPL builds. They both share just the header of the file. I wonder why we introduce a single vectors.S then. Wouldn't it be better to have a vectors.S for non-SPL builds and lets say a vectors_SPL.S for SPL builds?
Best regards
Andreas Bießmann