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.option norvc
.text
.global _start
_start:
lla t0, trap
csrw mtvec, t0
# These are all illegal instructions
csrw time, x0
.insn i CUSTOM_0, 0, x0, x0, 0x321
csrw time, x0
.insn i CUSTOM_0, 0, x0, x0, 0x123
csrw cycle, x0
# Success!
li a0, 0
j _exit
trap:
# When an instruction traps, compare it to the insn in memory.
csrr t0, mepc
csrr t1, mtval
lwu t2, 0(t0)
bne t1, t2, fail
# Skip the insn and continue.
addi t0, t0, 4
csrw mepc, t0
mret
fail:
li a0, 1
# Exit code in a0
_exit:
lla a1, semiargs
li t0, 0x20026 # ADP_Stopped_ApplicationExit
sd t0, 0(a1)
sd a0, 8(a1)
li a0, 0x20 # TARGET_SYS_EXIT_EXTENDED
# Semihosting call sequence
.balign 16
slli zero, zero, 0x1f
ebreak
srai zero, zero, 0x7
j .
.data
.balign 16
semiargs:
.space 16
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