[Qemu-devel] Re: [PATCH] Fix up pxe boot

[Avi Kivity]

Glauber Costa wrote:
> On Sun, Sep 07, 2008 at 09:42:07AM +0300, Avi Kivity wrote:
>   
> > Glauber Costa wrote:
> >     
> > > After a second look, here's what it seems to me:
> > >
> > > It's not in a generic place, such as ldl, because in general, we may want to 
> > > grab
> > > a 32-bit value from a 64-bit address. This is perfectly valid.
> > >
> > > It's a specifity that the pop instruction, when not in long mode (manual says 
> > > that in 64-bit mode
> > > no 32-bit operand is valid, but then again, qemu should use the POPQ macro), 
> > > that ssp:sp may overflow,
> > > but we don't want it.
> > >
> > > It would be possible to do something more generic if we had a 
> > > segment_to_linear() function, that returned
> > > the linear address, but we don't.
> > >
> > > Does it make more sense to you?
> > >   
> > >       
> > Yes.
> >
> > I guess tcg code is mostly safe since it generates 32-bit additions for  
> > segment bases, so this is limited to the places you identified.  And a  
> > helper to add segment bases would be helpful.
> >
> > --
> > error compiling committee.c: too many arguments to function
> >
> >     
>
> what do you think of the attached version?
>   

Looks fine to me.  One can thing of a cleverer helper (that receives the 
segment number and adds its base to the offset), but there's not reason 
to do this all at one.

--
error compiling committee.c: too many arguments to function