Int 67 Fn DE0C  - Virtual Control Program Interface - Switch To Protected  [E]

   AX = DE0Ch
   ESI = linear address in first megabyte of values for system
         registers (see #3336)
   interrupts disabled

Return: interrupts disabled
   GDTR, IDTR, LDTR, TR loaded
   SS:ESP must have at least 16 bytes space, and the entry point is
         required to set up a new stack before enabling interrupts
   EAX, ESI, DS, ES, FS, GS destroyed

Note:  in protected mode, calling the protected-mode VCPI entry point with
     AX = DE0Ch
     DS = segment selector mapping entire linear address space obtained
         via AX=DE01h
     SS:ESP in first megabyte of linear memory
     STACK:QWORD  return address from FAR call to 32-bit segment
       DWORD  EIP
       DWORD  CS
       DWORD  reserved for EFLAGS
       DWORD  ESP
       DWORD  SS
       DWORD  ES
       DWORD  DS
       DWORD  FS
       DWORD  GS
     and interrupts disabled, will switch to virtual86 mode with
       interrupts disabled, all segment registers loaded, and EAX
       destroyed.

See Also: AH=3Fh,INT 15/AH=89h,INT D4/AH=10h

Format of system register values for switch to protected mode:
Offset Size    Description (Table 3336)
 00h   DWORD   value for CR3
 04h   DWORD   linear address in first megabyte of value for GDTR
 08h   DWORD   linear address in first megabyte of value for IDTR
 0Ch   WORD    value for LDTR
 0Eh   WORD    value for TR
 10h   PWORD   CS:EIP of protected mode entry-point