Re: Linking non-PIC modules with PIC modules for MIPS SVR4.2MP

[Thiemo Seufer <ica2_ts at csv dot ica dot uni-stuttgart dot de>]

Kai Ruottu wrote:
[snip]
> but trying the '-Bstatic' and '-Bdynamic' for the same 'non-PIC'/'PIC'-mixing
> with GNU ld doesn't work.  It tells that it still cannot mix the PIC- and non-PIC
> stuff...   Is there any way to do this mixing?

Current binutils ld doesn't allow this. In theory, it should AFAICS be
possible to mix non-PIC/CPIC and PIC.

[snip]
> Disassembly of section .text:
> 
> 00000000 <_start>:
>    0:   3c1c0000        lui     gp,0x0
>    4:   279c0000        addiu   gp,gp,0

$gp setup is not needed for non-PIC.

[snip]
>   a0:   0c000000        jal     0 <_start>   <--- Some function called
>   a4:   00402021        move    a0,v0
>   a8:   0000000d        break
>   ac:   03e00008        jr      ra
>   b0:   00000000        nop

This isn't production ready, I assume. :-)

[snip]
> Is there any way to see the called function names and the names for the addresses
> in the disassembly listing?  Then cloning the current non-PIC 'crt1.o' could be a little
> more easy...

objdump -dr

[snip]
>   But if looking at the beginning of the startup, it looks having the tinkering
> with 'gp' as if it being a PIC-file... But 'readelf -h' claims it isn't...  Is here only a wrong
> flag in the file header?

I assume _gp results from setting up $gp at the beginning.

>  Anyway if the original non-PIC/PIC stuff could be used with the GNU ld, that would be
> best... Is there some way to do this now ?  For instance using the native linker etc. to
> convert the non-PIC stuff  into PIC-stuff.  This seems to happen now -- when looking
>  with 'objdump -d'  at the natively linked executable, the '_start' etc. stuff there is in
> PIC-mode and the whole executable is in the required PIC-mode...

I don't believe the native linker converts object files in such a way.
It might do mixed linking as mentioned above.


Thiemo