[coreboot] GSOC USBROM linking problem

[ron minnich]

On Wed, Jun 17, 2009 at 10:15 AM, Marc Jones<marcj303 at gmail.com> wrote:
> On Wed, Jun 17, 2009 at 11:05 AM, ron minnich<rminnich at gmail.com> wrote:
>> -fpic is the wrong way to go ... can we talk about this relocatable
>> code a bit? I need to catch up.
>
>
> The code is a PCI option ROM that can be copied and run at some
> arbitrary location between 0xC0000 and 0x100000. For 16bit code the
> segment would be loaded and there is no problem. I don't know the
> right way to do this for 32bit flat mode code.

I think we need to seek a common solution, and after discussion with
segher from a while back I think -fpic and -fpie as we do it in v3 are
rather questionable.

What we should look to do is a run command which sets a new entry in
the gdt and does a ljmp which sets CS to that entry. Then we link with
that code to run at 0. This is what FILO does and it works well.

thanks

ron