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Ring 0 from DJGPP?

Posted: Thu Apr 12, 2001 11:00 pm
by J. Weeks
This question kinda goes in with my previous one:

Is it possible to enter pmode with djgpp and cwsdpmi,
and then alter a few things to be more like my
OS environment (ie, IDT at 0x0, GDT at 0x800)?

I ask this, 'cuz my OS is currently hanging, rebooting, etc.
from code I can't yet isolate, so I'm hoping to
recreate my OS environment in DGJPP, so at least
_THEN_ I might get some valid pmode info when it
crashes (like HOW, and WHERE!)

Thanks,
J.W.

RE:ing 0 from DJGPP?

Posted: Thu Apr 12, 2001 11:00 pm
by Guest
>On 2001-04-13 17:40:26, J. Weeks wrote:
>This question kinda goes in with my previous one:
>
>Is it possible to enter pmode with djgpp and cwsdpmi,
>and then alter a few things to be more like my
>OS environment (ie, IDT at 0x0, GDT at 0x800)?

I think you can use the CWSDPR0.EXE DOS extender
(instead of CWSDPMI.EXE) to run at ring 0. Then
you can use the SGDT and SIDT instructions to
find out where the GDT and IDT are, and modify
them. I haven't tried this, though.



>
>I ask this, 'cuz my OS is currently hanging, rebooting, etc.
>from code I can't yet isolate, so I'm hoping to
>recreate my OS environment in DGJPP, so at least
>_THEN_ I might get some valid pmode info when it
>crashes (like HOW, and WHERE!)
>
>Thanks,
>J.W.