/* carve out a frame on current user stack */
sub sp, sp, #S_FRAME_SIZE
/* Save user registers (now in svc mode) r0-r12 */
stmia sp, {r0 - r12}
ldr r2, _armboot_start
sub r2, r2, #(CONFIG_SYS_MALLOC_LEN)
/* set base 2 words into abort stack */
sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8)
/* get values for "aborted" pc and cpsr (into parm regs) */
ldmia r2, {r2 - r3}
/* grab pointer to old stack */
add r0, sp, #S_FRAME_SIZE
add r5, sp, #S_SP
mov r1, lr
/* save sp_SVC, lr_SVC, pc, cpsr */
stmia r5, {r0 - r3}
/* save current stack into r0 (param register) */
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
add r8, sp, #S_PC @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
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
/* setup our mode stack (enter in banked mode) */
ldr r13, _armboot_start
/* move past malloc pool */
sub r13, r13, #(CONFIG_SYS_MALLOC_LEN)
/* move to reserved a couple spots for abort stack */
sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE + 8)
/* save caller lr in position 0 of saved stack */
str lr, [r13]
/* get the spsr */
mrs lr, spsr
/* save spsr in position 1 of saved stack */
str lr, [r13, #4]
/* prepare SVC-Mode */
mov r13, #MODE_SVC
@ msr spsr_c, r13
/* switch modes, make sure moves will execute */
msr spsr, r13
/* capture return pc */
mov lr, pc
/* jump to next instruction & switch modes. */
movs pc, lr
.endm
.macro get_bad_stack_swi
/* space on current stack for scratch reg. */
sub r13, r13, #4
/* save R0's value. */
str r0, [r13]
/* get data regions start */
ldr r0, _armboot_start
/* move past malloc pool */
sub r0, r0, #(CONFIG_SYS_MALLOC_LEN)
/* move past gbl and a couple spots for abort stack */
sub r0, r0, #(CONFIG_SYS_GBL_DATA_SIZE + 8)
/* save caller lr in position 0 of saved stack */
str lr, [r0]
/* get the spsr */
mrs r0, spsr
/* save spsr in position 1 of saved stack */
str lr, [r0, #4]
/* restore r0 */
ldr r0, [r13]
/* pop stack entry */
add r13, r13, #4
.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
.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_NAND_SPL */