Int 21 Fn 252B  P - Phar Lap 386/dos-extender V4.1+ - Map Data File At Fi  [E]

   AX = 252Bh
   BH = 0Bh
   BL = subfunction
       00h by linear address
       ECX = linear address at which to map data file
       01h by logical address
       ES:ECX = logical address at which to map data file
   EDX = number of bytes to map
   DS:ESI -> mapping structure (see below)
   DS:EDI -> ASCIZ filename

Return: CF clear if successful
   CF set on error
       EAX = error code
       0002h file error
           ECX = phase (01h opening file, 02h seeking, 03h reading)
           EDX = error code returned by DOS
       0009h invalid address
       0081h invalid parameters or 386|VMM not present
       0086h all 386|VMM file handles already in use

See Also: AX=252Bh/BH=03h,AX=252Bh/BH=09h

Format of mapping structure:
Offset Size    Description
 00h   DWORD   starting file offset to be mapped
 04h   DWORD   DOS file access and sharing modes (see INT 21/AH=3Dh)