On Fri, 01 Oct 2004 20:14:07 GMT, Tauno Voipio <tauno.voipio@iki.fi.NOSPAM.invalid> wrote:>Ignacio G.T. wrote: >> Bad news, David. I've just tried >> >> LGDT CS:[FFFFF888] >> >> and the results are the same. >> >> Intel's manual says this, for the LGDT instruction: >> > >Did you try > > LGDT CS:[f888] > >Please note that the processor is in *16* bit >mode till the descriptors are in and protected >mode is turned on.Thanks, Tauno. You are right. It works with this: 66 67 2E 0F 01 15 88 F8 00 00 i.e. LGDT CS:[0000F888]> >There is somewhere in the back of my trash box >a piece of code that boots an i386 into 32-bit >protected mode. If it is of any help, I could >find it among the dusty backup CD's.That would be great. Just in case I get stuck with the jump to protected mode.> >Tauno Voipio >tauno voipio (at) iki fi >-- Ignacio G.T.
Trying to load GDT into a psycho-Pentium
Started by ●September 30, 2004
Reply by ●October 4, 20042004-10-04
Reply by ●October 4, 20042004-10-04
On Fri, 01 Oct 2004 21:52:08 GMT, Jonathan Kirwan <jkirwan@easystreet.com> wrote:>Looks like you have had some good advice and thinking already. Rather than try >and understand it all, I'll just add some quick thoughts of my own. >[lots of useful info]> >Does any of that help? >Yes, Jon. Now I can LGDT using two different approaches and, best of all, I understand both ! -- Ignacio G.T.
Reply by ●October 4, 20042004-10-04
On Mon, 04 Oct 2004 09:32:16 GMT, igtorque.remove@evomer.yahoo.es (Ignacio G.T.) wrote:>Yes, Jon. Now I can LGDT using two different approaches and, best of all, I >understand both !Wonderful! I remember the first time I decided to write code to enter protected mode and some of the troubles. And... my excitement when I first turned on the paging system and remapped the VGA memory to a different linear address and it worked when I wrote characters there! (Interrupts disabled, that first time, because biting off setting up a decent IDT was a bit much.) I then went back to DOS mode and exited without crashing, afterwards! Wonderful feeling getting that right! Best of luck! Jon
Reply by ●October 7, 20042004-10-07
Ignacio G.T. wrote:> On Fri, 01 Oct 2004 20:14:07 GMT, Tauno Voipio > <tauno.voipio@iki.fi.NOSPAM.invalid> wrote: > > >>Ignacio G.T. wrote: > > That would be great. Just in case I get stuck with the jump to protected mode.Ignacio, please send me you working mail address. The yahoo.es address refused my mail. Correct my address in the sig in the obvous way to send. Tauno Voipio tauno voipio (at) iki fi
Reply by ●October 7, 20042004-10-07
> > That would be great. Just in case I get stuck with the jump to protectedmode. Try http://members.tripod.com/protected_mode/ and http://alexfru.narod.ru/ Alex
