/* SPDX-License-Identifier: GPL-2.0+ */ /* * vectors - Generic ARM exception table code * * Copyright (c) 1998 Dan Malek * Copyright (c) 1999 Magnus Damm * Copyright (c) 2000 Wolfgang Denk * Copyright (c) 2001 Alex Züpke * Copyright (c) 2001 Marius Gröger * Copyright (c) 2002 Alex Züpke * Copyright (c) 2002 Gary Jennejohn * Copyright (c) 2002 Kyle Harris */ #include /* * A macro to allow insertion of an ARM exception vector either * for the non-boot0 case or by a boot0-header. */ .macro ARM_VECTORS #ifdef CONFIG_ARCH_K3 ldr pc, _reset #else b reset #endif #if !CONFIG_IS_ENABLED(SYS_NO_VECTOR_TABLE) 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 .endm /* ************************************************************************* * * 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" #if defined(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. * * To allow a boot0 hook to insert a 'special' sequence after the vector * table (e.g. for the socfpga), the presence of a boot0 hook supresses * the below vector table and assumes that the vector table is filled in * by the boot0 hook. The requirements for a boot0 hook thus are: * (1) defines '_start:' as appropriate * (2) inserts the vector table using ARM_VECTORS as appropriate */ #include #else /* ************************************************************************* * * Exception vectors as described in ARM reference manuals * * Uses indirect branch to allow reaching handlers anywhere in memory. * ************************************************************************* */ _start: #ifdef CFG_SYS_DV_NOR_BOOT_CFG .word CFG_SYS_DV_NOR_BOOT_CFG #endif ARM_VECTORS #endif /* !defined(CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK) */ #if !CONFIG_IS_ENABLED(SYS_NO_VECTOR_TABLE) /* ************************************************************************* * * Indirect vectors table * * Symbols referenced here must be defined somewhere else * ************************************************************************* */ .globl _reset .globl _undefined_instruction .globl _software_interrupt .globl _prefetch_abort .globl _data_abort .globl _not_used .globl _irq .globl _fiq #ifdef CONFIG_ARCH_K3 _reset: .word reset #endif _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 #endif /* ************************************************************************* * * Interrupt handling * ************************************************************************* */ /* SPL interrupt handling: just hang */ #ifdef CONFIG_SPL_BUILD #if !CONFIG_IS_ENABLED(SYS_NO_VECTOR_TABLE) .align 5 undefined_instruction: software_interrupt: prefetch_abort: data_abort: not_used: irq: fiq: 1: b 1b /* hang and never return */ #endif #else /* !CONFIG_SPL_BUILD */ /* IRQ stack memory (calculated at run-time) + 8 bytes */ .globl IRQ_STACK_START_IN IRQ_STACK_START_IN: #ifdef IRAM_BASE_ADDR .word IRAM_BASE_ADDR + 0x20 #else .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_bad_stack_swi sub r13, r13, #4 @ space on current stack for scratch reg. str r0, [r13] @ save R0's value. ldr r0, IRQ_STACK_START_IN @ get data regions start str lr, [r0] @ save caller lr in position 0 of saved stack mrs lr, spsr @ get the spsr str lr, [r0, #4] @ save spsr in position 1 of saved stack ldr lr, [r0] @ restore lr ldr r0, [r13] @ restore r0 add r13, r13, #4 @ pop stack entry .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_swi bad_save_user_regs bl do_software_interrupt #if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK) ldmia sp, {r0 - lr}^ @ Calling r0 - lr mov r0, r0 ldr lr, [sp, #S_PC] @ Get PC add sp, sp, #S_FRAME_SIZE movs pc, lr @ return & move spsr_svc into cpsr #endif .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 .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_SPL_BUILD */