[linuxsh-dev] Re: Use of e_flags field in ELF header

[kaz K. <kk...@rr...>]

Hi,

"Thomas,Stephen" <ste...@su...> wrote:
>Apparently, the e_flags field of the ELF Header structure in ELF files
>is used by SH architectures to indicate the CPU type. The lower 5 bits
> have the following meaning:
>
>     0  = unknown CPU type
>     1  = SH1
>     2  = SH2
>     3  = SH3
>     5  = SH3 with DSP
>     8  = SH3E
>     9  = SH4
>    10  = SH5
>
>The e_flags field is designed to hold architecture specific info, but
>other architectures don't appear to use it in quite the same way, i.e.
>to indicate different CPU types.
>
>Does anybody know why SH uses e_flags in this way?

I don't know why SH does so, but MIPS uses the upper 4 bits of e_flags
to encode ISA. Perhaps there might be another examples.

>The problem I have is in generating & interpreting core files. When
>the kernel (V2.4)generates an ELF core dump, it just sets e_flags to 0
>(hard coded constant) & dumps it. So to get it to generate a valid SH5
>core dump, I need to modify generic code. There are similar problems
>with the gdb 'gcore' command.

Your modification seems the right thing to do.

Regards,
	kaz