arm: move exception handling out of start.S files
Exception handling is basically identical for all ARM targets.
Factorize it out of the various start.S files and into a
single vectors.S file, and adjust linker scripts accordingly.
Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
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 */