Note: This API calls are shared between DOS and Win16 personality.
DPMI is a shared interface for DOS applications to access Intel 80286+ CPUs services. DOS DMPI host provides core services for protected mode applications. Multitasking OS with DOS support also provides DMPI in most cases. Windows standard and extended mode kernel is a DPMI client app. Standard and extended mode kernel differs minimally and shares common codebase. Standard Windows kernel works under DOSX extender. DOSX is a specialized version of 16-bit DPMI Extender (but it is standard DPMI host). Standard mode is just DPMI client, exnhanced mode is DPMI client running under Virtual Machime Manager (really, multitasker which allow to run many DOS sessions). Both modes shares DPMI interface for kernel communication. The OS/2 virtual DOS Protected Mode Interface (VDPMI) device driver provides Version 0.9 DPMI support for virtual DOS machines. Win16 (up to Windows ME) provides Version 0.9 DPMI support. Windows in Standard Mode provides DPMI services only for Windows Applications, not DOS sessions.
DPMI host often merged with DPMI extender. Usually DPMI extender provide DPMI host standard services and DOS translation or True DPMI services.
Int 31H, AH=00H, AL=0EH
Version
1.0
Brief
Get Multiple Descriptors
Input
AX = 000EH CX = number of descriptors to copy ES:(E)DI = selector:offset of a buffer in the following format:
| Offset | Length | Contents |
|---|---|---|
| 00H | 2 | Selector #1 (set by client) |
| 02H | 8 | Descriptor #1 (returned by host) |
| 0AH | 2 | Selector #2 (set by client) |
| 0CH | 8 | Descriptor #2 (returned byhost) |
| … | … | … |
if function successful Carry flag = clear and buffer contains copies of the descriptors for the specified selectors if function unsuccessful Carry flag = set AX = error code 8022H invalid selector CX = number of descriptors successfully copied
Notes
Copies one or more local descriptor table (LDT) entries into a client buffer.
If an error occurs because of an invalid selector or descriptor, the function returns the number of descriptors which were successfully copied in CX. All of the descriptors which were copied prior to the one that failed are valid.
32-bit programs must use ES:EDI to point to the buffer. 16-bit programs should use ES:DI.
Refer to the rules for descriptor usage in Appendix D.
See also
Note
Text based on http://www.delorie.com/djgpp/doc/dpmi/