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