Re: Proposed targets to obsolete for gcc 3.5

Ian Dall wrote:
> This glosses over one thing. Dynamic linking. The FSF binutils doesn't
> have support dynamic linking on the ns32k. I've had a look a few times at
> the changes made to support dynamic linking in the old binutils branch
> used by NetBSD, but I've never fully understood them.
> 
> I suspect not that much is needed, but as usual, the problem is
> knowing what. I think we link to global symbols in shared objects by
> fiddling entires in a global offset table, at run time. I think they
> will all be straight two's complement numbers so the ns32k's ah
> richness doesn't bite. What I don't understand is what the
> pre-exisiting elf relocation types are, and which ones match the ns32k
> types and what needs to be ns32k specific.

That's more or less where I gave up (mostly due to lack of energy).
In order to support dynamic linking one has to hack gas as well. Iirc
it's only recognizing sb-relative references and augmenting their
relocationinformation with RELOC_GLOB_DAT. The other thing one has to do
is to set the relocationtype to jmpslot for undefined pc-relative
relocations. Just have a look into gnu/usr.bin/gas/config/tc-ns32k.c
(it's in the attic...) and search for PIC. Compared to 68k or i386 it's
really simple :-).

Anybody needing information on dynamic linking on the ns32k can get
whatever I can find in the offline storage area of my brain...

For the kernel and the library routines I tried to gate all
symbolreferences through _C_LABEL in order to make it possible to remove
the leading _ without too much trouble.

Matthias
-- 
Matthias Pfaller                            Software Entwicklung
marco Systemanalyse und Entwicklung GmbH    Tel   +49 8131 5161 41
Hans-Böckler-Str. 2, D 85221 Dachau         Fax   +49 8131 5161 66
http://www.marco.de/                        Email [email protected]