Re: [Qemu-devel] AMD64 Gentoo needs help

[J. Mayer]

On Thu, 2004-09-23 at 22:21, Martin Garton wrote:
> On Thu, 23 Sep 2004, jmf wrote:
> 
Hi,

> > I treid that and before the segfault below happen, now a black window
> > appears and dissappears very quickly
> 
> I believe the problem is that qemu is not 64bit clean code because it does 
> things like casting from pointers to ints and back which is okay when they 
> are the same size (ie, on x86) but not when a pointer is twice as long as 
> an int (ie, on amd64) You will have seen warnings about this when 
> compiling.

You may like to know that the ppc emulation runs well on amd64. A lots
of 64 bits cleanup have already been made. The warning you get during
compilation (should) concern only addresses in the emulated environment.
As qemu only emulates 32 bits machines for now, it's not a real issue.

The only way I ever succeeded running qemu-x86 on amd64 is to compile
and execute it into a 32 bits chrooted environment: I got a full 32 bits
gentoo into a separate partition to achieve this.

> 
> I looked at the code with a view to making it amd64 friendly, but I'm out 
> of my depth.  If someone wants to give me some hints I might find some 
> time to have another look though.

I think the issues may be located in or very near the x86 emulation
code. I never had the courage to compare step by step the execution in
the 32 bits vs the 64 bits environment to find where is the bug, but I
really think there is just a few bugs to locate and fix.

Regards.

-- 
J. Mayer <address@hidden>
Never organized