Re: [Qemu-devel] RFC: linux user problems

["J. Mayer" <l_indien@magic.fr>]

On Mon, 2007-09-17 at 23:10 +0100, Paul Brook wrote:
> On Monday 17 September 2007, J. Mayer wrote:
> > It seems to me that there are many problems in linux-user/syscall.c
> > - problems for 64 bits targets:
> > it seems that do_syscall and child functions should take target_long /
> > target_ulong arguments instead of long / unsigned long. This would make
> > a chance for 64 bits targets to be ran on 32 bits hosts (even if, yes,
> > there would also be other problems to fix elsewhere...).
> 
> IIRC most of code predates target_long. I'm surprised 64-bit targets work at 
> all.

Well, in fact I already did this (mostly alpha emulation). But running
on a 64 bits host platform, which may explain I've been able to start
running anything !...
I'd like to make this more reliable in order to test some PowerPC 64
code without the need of the full MMU emulation (which is not complete
and far from being debugged...) and any firmware.

> > there should be a target_short definition: are we sure short on the host
> > is always the same size than target_short ?
> 
> Short is the same 16-bit type on every host or target we're even vaguely 
> likely to care about.
> 
> I can only think of one system (a weird and fairly obscure DSP) where this is 
> not true. You'd definitely not be running linux, and almost certainly not be 
> running qemu on it.

OK, so there's no issue with this. But there always seem to be an issue
confusing short with long or target_long...

I go on checking the syscall.c code, converting long to target_long when
it seems correct and preparing remarks and/or questions for all other
cases.

Regards.

-- 
J. Mayer <l_indien@magic.fr>
Never organized