Mail Archives: djgpp-workers/2001/05/01/07:31:39
On Tue, 1 May 2001, The Owl wrote:
> 1. the dpmi app issues a real mode (v86) int 2f/1687 to learn about the
> dpmi mode switch entry point. the interrupt is serviced by dosx in its
> RMINT2FHANDLER function (it has been set as the int 2f handler during
> dosx initialization). the mode switch routine is inside dosx and is
> called DPMI_CLIENT_PMODE_ENTRY.
>
> 2. the dpmi app calls DPMI_CLIENT_PMODE_ENTRY to enter protected mode.
> this function first issues a real mode int 21/62 to get the current
> real mode PSP segment, then switches to pmode by using ntvdm's Bop
> interface. once in pmode, dosx allocates various selectors, one of
> them will be the PSP alias selector. then dosx notifies ntvdm about
> the startup of a new dpmi app. ntvdm executes _DpmiInitApp AT 0 which
> will set _CurrentPSPSelector (among other things).
Thanks, I think I understand now.
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