Int 2C Fn 0009  P - Rm386 V6.00 - Cloaking - Set Passalong Address         [m]

   AX = 0009h
   DX:EBX = new value for passalong address

Return: CF clear

Note:  when an INT 2C instruction is executed in V86 mode, RM386 calls the
     passalong address.  The handler should check whether the upcall
     is of interest to it, and if not it should jump to the old passalong
     address (retrieved with AX=0008h before the handler was installed)

See Also: AX=0008h,AX=002Dh,INT 2C"CLOAKING"

Passalong address called with:
   EAX = CS:IP of byte following INT 2C instruction invoking passalong
   SS:EBX -> caller registers (see below)
   CF clear
   others undefined

Return: CF clear: pass along to V86-mode INT 2C handler
   CF set: return immediately to V86 mode

Format of caller registers:
Offset Size    Description
 00h   DWORD   EDI
 04h   DWORD   ESI
 08h   DWORD   EBP
 0Ch   DWORD   reserved (ESP from PUSHAD instruction)
 10h   DWORD   EBX
 14h   DWORD   EDX
 18h   DWORD   ECX
 1Ch   DWORD   EAX
 20h   DWORD   error code
 24h   DWORD   EIP
 28h   WORD    CS
 2Ah   WORD    padding
 2Ch   DWORD   EFLAGS
 30h   DWORD   ESP
 34h   WORD    SS
 36h   WORD    padding
--remainder not available if protected-mode ring3 trap---
 38h   WORD    ES
 3Ah   WORD    padding
 3Ch   WORD    DS
 3Eh   WORD    padding
 40h   WORD    FS
 42h   WORD    padding
 44h   WORD    GS
 46h   WORD    padding