Returns: CF NC (this fn always succeeds)
BX:CX real-mode address of routine to switch to protected mode
SI:DI (or SI:EDI) prot mode addr of routine to switch to real mode
Info: This is used by applications which perform low-level mode
switching. It obtains the addresses of the DPMI routine which
switches into or out of real mode.
task when you perform raw mode-switching.
BX:CX this address can be called by real-mode applications to switch to
SI:(E)DI this address can be called by protected-mode applications to
Both of these routines are accessed via FAR JMP and expect:
The host switches modes, and sets DS, ES, SS, and (E)SP, and
Notes: It is your responsibility to save and restore the CPU state
force mode switching, since they handle the overhead.