Re: [Qemu-devel] Stuff.

[Chris Emerson <qemu@mail.nosreme.org>]

On Tue, May 04, 2004 at 10:31:09PM +0100, David Woodhouse wrote:
> Has anyone considered the possibility of emulating libc, rather than
> emulating system calls? That's what em86 used to do for emulating i386
> code on Alpha -- rather than letting it run a 'real' non-native libc
> and then emulating only syscalls. 

I did this with my own i386-on-ppc emulator.  It's a larger and less
well documented ABI, and can get quite messy.  OTOH, most of the
functions are easy and could be generated.

> I appreciate that syscalls are a far more stable ABI to be emulating,
> and there are far fewer structures to convert -- but wouldn't it be
> faster to emulate the library itself?

Probably, but I'd be interested to see some profiling data showing how
much time is actually spent emulating the libc etc. first.

> It's cute that I have i386 acroread running in a Mozilla window
> through mozplugger.

Ooh, I'll have to look into that.  Maybe I can have Flash on Linux/PPC
after all...

> It'd be cuter if I could get Mozilla plugins running in the _same_
> process, rather than in a separate process. 

You'd need to know the prototypes of all the functions you're calling
ahead of time, though...

Chris