Re: [Etherboot-developers] Adding real-mode stack for prot_to_real

[Marc S. <el...@bu...>]

On Sat, Sep 21, 2002 at 03:38:38PM +1000, Ken Yap wrote:
> >We also need to load the GDT, and segment registers with the values
> >mknbi assumes are in use.  A protected mode entry point can only
> >sanely assume a flat 32bit address space with a base address of 0.
> >I have played with the former and checked it into the developer etherboot
> >CVS tree.  But I had not identified the remaing stack issue.
> 
> I have some time this weekend and will get a round tuit. It's fairly
> easy to fix, just do what menustart.S does, that is, switch GDTs, get a
> private stack, in this case at the top of the 6kB allocated to
> first32.c, then copy the 3 arguments over and jump to the entry point of
> first32.c.

I just posted a patch that does this.  I used a 4K stack and I copy
more than 3 arguments since it's easy to do so.  I also made an
allowance so that we could return to etherboot if necessary.