[SeaBIOS] Problems with Linux payload

Kevin O'Connor kevin at koconnor.net
Thu Aug 28 01:19:49 CEST 2014


On Thu, Aug 28, 2014 at 01:12:48AM +0200, Laszlo Ersek wrote:
> On 08/27/14 23:17, Curt Brune wrote:
> >   GDT=     000f4b78 00000037
[...]
> I'll probably make a clown out of myself, but I'll just blurt out that
> the direct value of SS (0x18) is quite meaningless, it's just a segment
> *selector* value. What is interesting is the contents of the GDT entry,
> at byte offset 0x18 (which corresponds to the fourth GDT entry).
> 
> In your first register dump, you have
> 
> GDT=     000f4b78 00000037

Oh, I missed that the GDT address was actually in the register dump.
It's definitely wrong for that code to be using the SeaBIOS' gdt.
So, something neglected to call "lgdt".  Only question is whether it's
the bootstrap or Linux itself that was supposed to do it.

-Kevin



More information about the SeaBIOS mailing list