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; ###----------------------------------------------------------------###
; # file : syscall_00.s #
; # date : Mar 26 1996 #
; # descr. : functional test for mips #
; ###----------------------------------------------------------------###
; ###--------------------------------------------------------###
; # exceptions : #
; # - syscall #
; ###--------------------------------------------------------###
val1 .equ 0x3C
val .equ 0x20
.org 0x80000080
.start it_handler
; ###--------------------------------------------------------###
; # interrupt and exception handler #
; ###--------------------------------------------------------###
it_handler:
sw r29, 0 (r30)
sw r28, 4 (r30)
addi r28, r0, val1
mfc0 r29, cause
nop
and r29, r29, r28
addi r27, r0, val
bne r29, r27, not_good
nop
lw r29, 0 (r30)
lw r28, 4 (r30)
; ###--------------------------------------------------------###
; # restore return address before returning (from EXCEPTION) #
; # to the user program (address must be saved by the user #
; # prior to the EXCEPTION in epc) #
; ###--------------------------------------------------------###
restore_return_adr:
mfc0 r31,epc
nop
addi r31,r31,8
jr r31
rfe
not_good:
mfc0 r31,epc
nop
addi r31,r31,4
jr r31
rfe
.end
|
