.globl _start
_start:
b reset
-#ifdef CONFIG_SPL_BUILD
-/* No exception handlers in preloader */
- ldr pc, _hang
- ldr pc, _hang
- ldr pc, _hang
- ldr pc, _hang
- b reset
- ldr pc, _hang
- ldr pc, _hang
+ b undefined_instruction
+ b software_interrupt
+ b prefetch_abort
+ b data_abort
+ b not_used
+ b irq
+ b fiq
-_hang:
- .word do_hang
-/* pad to 64 byte boundary */
- .word 0x12345678
- .word 0x12345678
- .word 0x12345678
- .word 0x12345678
- .word 0x12345678
- .word 0x12345678
- .word 0x12345678
-#else
- 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
+/*
+ * Vector table, located at address 0x20.
+ * This table allows the code running AFTER SPL, the U-Boot, to install it's
+ * interrupt handlers here. The problem is that the U-Boot is loaded into RAM,
+ * including it's interrupt vectoring table and the table at 0x0 is still the
+ * SPLs. So if interrupt happens in U-Boot, the SPLs interrupt vectoring table
+ * is still used.
+ */
+_vt_reset:
+ .word _reset
+_vt_undefined_instruction:
+ .word _hang
+_vt_software_interrupt:
+ .word _hang
+_vt_prefetch_abort:
+ .word _hang
+_vt_data_abort:
+ .word _hang
+_vt_not_used:
+ .word _reset
+_vt_irq:
+ .word _hang
+_vt_fiq:
+ .word _hang
-_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
+reset:
+ ldr pc, _vt_reset
+undefined_instruction:
+ ldr pc, _vt_undefined_instruction
+software_interrupt:
+ ldr pc, _vt_software_interrupt
+prefetch_abort:
+ ldr pc, _vt_prefetch_abort
+data_abort:
+ ldr pc, _vt_data_abort
+not_used:
+ ldr pc, _vt_not_used
+irq:
+ ldr pc, _vt_irq
+fiq:
+ ldr pc, _vt_fiq
-#endif /* CONFIG_SPL_BUILD */
.balignl 16,0xdeadbeef
-
/*
*************************************************************************
*
* the actual reset code
*/
-reset:
+_reset:
/*
* Store all registers on old stack pointer, this will allow us later to
* return to the BootROM and let the BootROM load U-Boot into RAM.
mcr p15, 0, r0, c1, c0, 0
mov pc, lr /* back to my caller */
-#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
-
-#ifndef CONFIG_SPL_BUILD
-/*
- *************************************************************************
- *
- * Interrupt handling
- *
- *************************************************************************
- */
-
-@
-@ 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:
+#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
+
+_hang:
ldr sp, _TEXT_BASE /* switch to abort stack */
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 */
projects / karo-tx-uboot.git / commitdiff