参照元†
返り値†
.macro svc_entry, stack_hole=0
UNWIND(.fnstart )
UNWIND(.save {r0 - pc} )
sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
#ifdef CONFIG_THUMB2_KERNEL
SPFIX( str r0, [sp] ) @ temporarily saved
SPFIX( mov r0, sp )
SPFIX( tst r0, #4 ) @ test original stack alignment
SPFIX( ldr r0, [sp] ) @ restored
#else
SPFIX( tst sp, #4 )
#endif
SPFIX( subeq sp, sp, #4 )
stmia sp, {r1 - r12}
ldmia r0, {r1 - r3}
add r5, sp, #S_SP - 4 @ here for interlock avoidance
mov r4, #-1 @ "" "" "" ""
add r0, sp, #(S_FRAME_SIZE + \stack_hole - 4)
SPFIX( addeq r0, r0, #4 )
str r1, [sp, #-4]! @ save the "real" r0 copied
@ from the exception stack
mov r1, lr
@
@ We are now ready to fill in the remaining blanks on the stack:
@
@ r0 - sp_svc
@ r1 - lr_svc
@ r2 - lr_<exception>, already fixed up for correct return/restart
@ r3 - spsr_<exception>
@ r4 - orig_r0 (see pt_regs definition in ptrace.h)
@
stmia r5, {r0 - r4}
asm_trace_hardirqs_off
.endm
コメント†