Re: illegal hardware instruction during MIPS-I ELF linux user emulation

[Peter Maydell <peter.maydell@linaro.org>]

On Mon, 23 Sep 2019 at 13:08, Libo Zhou <zhlb29@foxmail.com> wrote:
>
> Any help guys? Is there a way to look at the ELF binary code to see if the instructions have invalid encoding scheme? Since I used a custom compiler that claims to have MIPS-I instructions. I doubt it though because 'file' command gives a reasonable output saying it surely is MIPS-I.

'file' just looks at the header on the file to see what it
claims to be. It doesn't look through the rest of the file
to check what actual instructions the compiler emitted.
You can use 'objdump' if you want to disassemble a file.

I would start by using the QEMU gdbstub to connect a
MIPS-aware gdb. Then when the SIGILL arrives you can see
what instruction the guest program was trying to execute.

thanks
-- PMM