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Re: working xfree86 4.1.0?



On Thursday 20 December 2001 06:10, Christian T. Steigies wrote:
> Hi folks,
> I've built xfree86 4.1.0 with Eric's elfloader patch and put them on:
>  http://people.debian.org/~cts/xfree86-4.1.0/
>
> This one still contains debugging code, so its pretty slow on startup. But
> it does not crash anymore (immediately) when loading modules. I do not have
> a working XF86Config-4 yet for my m68k box, but I am somewhat convinced
> that this patch may solve the problem. If somebody wants to test it, go and
> get it while its still hot.

(I'm not sure wether I mailed this before, but I'll reply anyway. Yes, it's a 
 bit late, but better late than never)

Back in 2000 I had a working X 3.9.x on my Amiga. Unfortunately I let it slip 
and things progressed since, and when I tried using the diffs I made back 
then with 4.1.X things no longer worked.

There were a number of problems back then, the most annoying one being the 
ELF loader. There was code for m68k in, but it was broken.

I checked the current CVS version and it looks better now, but it's not OK 
yet. The relocation is OK now, but one important bit is still missing: 
flushing the instruction cache! This is probably the reason for the SEGV in 
the server. I have a 68060 so it crashes nicely, whereas it might work on 
68030 CPUs.

I'll dig up my patch to see if I can get it working again, but I remember it 
being a bit kludgy because we have no equivalent of ppc_flush_icache() on 
m68k. There is __cache_flush() in libgcc (or was it libc?) but its API is 
quite different. And instead of flushing a cache line (?) for each relocated 
address (which is what PPC seems to do) we might be better off flushing the 
cache for the entire relocated section after it's been relocated (I think 
__cache_flush() wants a start address and a length argument).
Or maybe we should use the m68k cacheflush syscall() instead.

Anyone? Andreas? What's better?

This time I'll promise not to delete the xc tree again until I send a patch 
to XFree86 ;)

Debugging the modules is a real pain without the XFree86 gdb patch by the 
way, is there anyone who built a gdb with that patch for m68k?

Kind regards,

Kars de Jong
Keeping m68k alive



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