Mail Archives: djgpp/2000/04/02/12:15:42
On Sun, 2 Apr 2000, Eli Zaretskii wrote:
> On 23 Mar 2000, Mark Geisert wrote:
> > Can programs in DOS boxes issue the NT syscall interrupt 0x2E successfully?
> > If so, perhaps one could try a no-params-supplied syscall to a service
> > added for Win2K. One might be able to distinguish "invalid params" type
> > error from "service not supported" type error when attempted on WinNT4.
>
> What service would you suggest to try this method?
Hi Eli,
The NT syscalls are amazingly underdocumented considering how widely NT
is used. I don't have a specific syscall in mind.
My understanding is that the list of syscalls changes from release to
release and syscalls could even be added by service pack. I've not been
able to find the mapping between syscalls (the Zw... exports from
NTDLL.DLL I think (don't have my notes handy)) and the service numbers
that you'd put in EAX to invoke the syscall via Int 0x2E. I have some
leads on that which I haven't yet followed.
I was actually considering something risky to determine if this strategy
would work at all, which would be to just try various small values in EAX.
The only other param needed for the syscall is a pointer to a param block
in EDX, which I was going to just zero out.
I would expect NT to do a better job at failing invalid syscalls than the
other Windows versions, but who knows :).
BTW I've been peripherally following DJGPP for years, especially DPMI and
process management issues, but I've never actually installed it anywhere.
Perhaps this could be my excuse to get involved.
Regards,
Mark Geisert
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