On Wednesday 25 March 2015 13:13:14 James Hogan wrote:
> Hi Duarte,
>
> On 22/03/15 11:13, Duarte Silva wrote:
> > Hi guys,
> >
> > I have been struggling to get some binaries compiled for NetLogic XLP
> > processor to run under QEMU. I have tried a bunch of things (most going
> > back and forth) and always get the following error message:
> >
> > qemu: uncaught target signal 4 (Illegal instruction) - core dumped
> > Illegal instruction
> >
> > I tried to debug it using GDB but to no avail. Does anybody have ideas?
> > I'm
> > running QEMU 2.2.1.
>
> It sounds like the program had an instruction that QEMU doesn't
> recognise, or doesn't think should be allowed on the current CPU which
> you've set with -cpu. You might be able to find out what that
> instruction is by putting this on your qemu command line:
>
> -singlestep -d in_asm
Hi James,
thanks for the help :) I have tried with all the CPU's available. None of them
worked, so I just leave it as undefined. It seems the offending instruction is
"udi4".
(...)
IN:
0x765d1fa4: udi4 a0,v0,zero,0x0
OUT: [size=84]
0x606026b0: mov -0x4(%r14),%ebp
0x606026b4: test %ebp,%ebp
0x606026b6: jne 0x606026f5
0x606026bc: mov $0x765d1fa4,%ebp
0x606026c1: mov %ebp,0x80(%r14)
0x606026c8: mov %r14,%rdi
0x606026cb: mov $0x14,%esi
0x606026d0: callq 0x600acaa0
0x606026d5: jmpq 0x606026da
0x606026da: mov $0x765d1fa8,%ebp
0x606026df: mov %ebp,0x80(%r14)
0x606026e6: mov $0x7fe1de9d3bc0,%rax
0x606026f0: jmpq 0x62561d26
0x606026f5: mov $0x7fe1de9d3bc3,%rax
0x606026ff: jmpq 0x62561d26
do_raise_exception_err: 20 0
qemu: uncaught target signal 4 (Illegal instruction) - core dumped
Illegal instruction
I have found on QEMU code the following definitions for udi4 (on file
disas/mips.c):
{"udi4", "s,t,d,+1", 0x70000014, 0xfc00003f, WR_d|RD_s|RD_t, 0, I33 },
{"udi4", "s,t,+2", 0x70000014, 0xfc00003f, WR_d|RD_s|RD_t, 0, I33 },
{"udi4", "s,+3", 0x70000014, 0xfc00003f, WR_d|RD_s|RD_t, 0, I33 },
{"udi4", "+4", 0x70000014, 0xfc00003f, WR_d|RD_s|RD_t, 0, I33 },
Does any of these match the above instruction? It seems so no?
Cheers,
Duarte
>
> that will cause it to only translate one instruction at a time, and to
> dump each one as it is translated. The last one printed will very likely
> to be the one that is causing the problem.
>
> Cheers
> James
