Re: Can't debug core files with GDB

[Johannes Stezenbach <js@linuxtv.org>]

On Fri, May 26, 2006, Tony Lin wrote:
> Finally found the place in gdb to change the register values to read
> the coredump correctly. However I have a nagging feeling that I may
> not have configured gdb correctly , and my fix may not be the right
> one. But oh wells, at least it works!
> 
> cross-compiled on: i386-linux
> configured gdb using: ../gdb/configure --target=mips-linux
> gdb-6.4, kernel 2.6.6-rc3, gcc-3.4.3
> 
> *** mips-linux-tdep.c   2006-05-26 17:14:00.577339000 -0700
> --- mips-linux.tdep.c~  2006-05-26 17:15:53.723372000 -0700
> ***************
> *** 54,65 ****
> --- 54,76 ----
> +
> + /* NEW 2.6 style */
> + #define EF_CP0_STATUS         38
> + #define EF_LO                 39
> + #define EF_HI                 40
> + #define EF_CP0_BADVADDR               41
> + #define EF_CP0_CAUSE          42
> + #define EF_CP0_EPC            43
> +
> + /* OLD 2.4 style
>  #define EF_LO                 38
>  #define EF_HI                 39
>  #define EF_CP0_EPC            40
>  #define EF_CP0_BADVADDR               41
>  #define EF_CP0_STATUS         42
>  #define EF_CP0_CAUSE          43
> + */
> 
> Is it possible that since I cross-compiled gdb on an i386, it used the
> local gcc/libc to compile and didn't have the right registers header
> file? I know during configuration it was complaining that it didn't
> find greg_t definitions etc. I suppose this why you guys can compile
> it correctly on the native mips-linux while I have issues
> cross-compiling on i386-linux.

Maybe the change to the coredump format was reverted in later
2.6 kernels. If so, Ralf might remember.

Johannes