en:docs:dpmi:api:int31:01:01

Note: This API calls are shared between DOS and Win16 personality.

DOSX is a specialized version of DPMI. Windows standard and extended mode kernel is a DPMI client app. Standard and extended mode kernel differs minimally and shares common codebase. Standard mode is just DPMI client, exnhanced mode is DPMI client running under Virtual Machime Manager. 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 provides Version 1.0 DPMI support, but reported as 0.9.

2021/08/05 12:15 · prokushev

Int 31H, AH=01H, AL=01H

Version

0.9

Brief

Free DOS Memory Block

Input

AX = 0101H
DX = selector of block to be freed
      

Return

if function successful
Carry flag = clear

if function unsuccessful
Carry flag = set
AX = error code
0007H	memory control blocks damaged (also returned by DPMI 0.9 hosts).
0009H	incorrect memory segment specified (also returned by DPMI 0.9 hosts).
8022H	invalid selector

Notes

Frees a memory block that was previously allocated with the Allocate DOS Memory Block function (Int 31H Function 0100H).

All descriptors allocated for the memory block are automatically freed by this function, and are no longer valid after this function returns.

Under DPMI 1.0 hosts, any segment registers which contain a selector being freed are zeroed by this function.

Refer to the rules for descriptor usage in Appendix D.

See also

Note

DPMI
Process manager INT 2FH 1680H, 1687H
Signals
Memory manager
Misc INT 2FH 1686H, 168AH
Devices
2021/08/13 16:23 · prokushev

en/docs/dpmi/api/int31/01/01.txt · Last modified: 2021/08/27 04:03 by prokushev