Query...

[MNShukla]

Hi Nick,

Nick Clifton wrote:

> Hi Shukla,
>
> > I am generating obj files by using ARM-gcc, gcc-for-PC(intel) and
> > ARM-ADS. I am getting difference in the ELF-header, the values of
> > EI_PAD of e_ident[] is as follows--
> >
> > EI_PAD = 0x61 for ARM-gcc and
> > EI_PAD = 0x00 for ARM-ADS and PC-gcc.
> >
> > Can somebody point me what does it signify?
>
> You are looking at an old version of the ELF spec.  That field
> (e_ident[7]) is now called EI_OSABI, and the EI_PAD field is now two
> bytes further on.
>
> The EI_OSABI field is used to distinguish binaries for the same
> architecture but which target different Operating Systems and/or
> different Application Binary Interfaces.  A value of 0 means "default"
> or "uninitialised".  A value of 0x61 (or 97 in decimal) is defined in
> the spec as:
>
>   #define ELFOSABI_ARM   97     /* ARM */
>
> In the case of GCC this field is being used to distinguish between
> binaries built by old versions of gcc (which set the field to 0)
> and new(er) versions of gcc.  The older versions did not implement the
> ARM ELF ABI correctly, and so the linker has to work around this
> problem, provided that it can detect the old binaries.
>

Can OBJ's, created by older ELF spec., be linked with GCC-linker which
uses newer ELF spec.?
Actually, I want to create OBJ's by using ARM-ADS(v1.1) and link it with
arm-linux-gcc.

>
> > Now, if I want to link obj's generated by ARM-ADS with obj generated
> > by ARM-gcc, it is not able to link and says format different.
>
> What, precisely, is the error message that you are receiving ?
>

The error messages areas---
-------/bin/ld : Error : strlen.o compiled for EABI version 0, whereas
MN1.out is compiled for version 2.
File format not recognized : failed to merge target specific data of file
............./lin/libc.a (strlen.o)

-------/bin/ld : Error : write.o compiled for EABI version 0, whereas
MN1.out is compiled for version 2.
File format not recognized : failed to merge target specific data of file
............./lin/libc.a (write.o)

-------/bin/ld : Error : fflush.o compiled for EABI version 0, whereas
MN1.out is compiled for version 2.
File format not recognized : failed to merge target specific data of file
............./lin/libc.a (fflush.o)

-------/bin/ld : Error : freer.o compiled for EABI version 0, whereas
MN1.out is compiled for version 2.
File format not recognized : failed to merge target specific data of file
............./lin/libc.a (freer.o)

-------/bin/ld : Error : lseeker.o compiled for EABI version 0, whereas
MN1.out is compiled for version 2.
File format not recognized : failed to merge target specific data of file
............./lin/libc.a (lseeker.o)
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With Best Regards,

Shukla
(Mahesh Narain Shukla)