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Diffstat (limited to 'arch/arm/lib/vectors.S')
| -rw-r--r-- | arch/arm/lib/vectors.S | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/arch/arm/lib/vectors.S b/arch/arm/lib/vectors.S new file mode 100644 index 0000000..d68cc47 --- /dev/null +++ b/arch/arm/lib/vectors.S @@ -0,0 +1,291 @@ +/* + * 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 + +_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 + +/* + ************************************************************************* + * + * 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 + +_reset: .word reset +_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 */ |