Windows2003-3790/base/mvdm/dos/v86/redir/int2a.asm
2020-09-30 16:53:55 +02:00

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3.9 KiB
NASM

page ,132
if 0
/*++
Copyright (c) 1991 Microsoft Corporation
Module Name:
int2a.asm
Abstract:
This module contains the int 2a handler for the NT VDM redir TSR
Author:
Richard L Firth (rfirth) 29-Oct-1991
Environment:
Dos mode only
Revision History:
05-Sep-1991 rfirth
Created
--*/
endif
.xlist
.xcref
include rdrsvc.inc ; SVC
include debugmac.inc ; debug display macros
include segorder.inc ; load order of 'redir' segments
.cref
.list
.286 ; all code in this module 286 compatible
ResidentCodeStart
assume cs:ResidentCode
assume ds:nothing
assume es:nothing
assume ss:nothing
public Old2aHandler
Old2aHandler dd ?
; *** Int2aHandler
; *
; * Handles int 2a requests, in which we pretend to be minses and any
; * other missing parts of the net stack
; *
; * ENTRY function code in ah:
; * ah = 0, return ah = 1
; * ah = 1, Cooked NetBIOS call
; * ah = 4, al = 0, same as ah = 1
; * al = 1, Raw NetBIOS call
; * al = 2, unknown function; we don't handle it
; * See doslan\minses\int2a.inc in LANMAN
; * project for details
; * ah = 5, Get Adapter Resources. Returns in CX number of
; * available NCBs and in DX the number of available
; * sessions. We don't (as yet) handle this
; *
; * es:bx = NCB
; *
; * EXIT See above
; *
; * USES ax, flags
; *
; * ASSUMES nothing
; *
; ***
public Int2aHandler
Int2aHandler proc near
or ah,ah ; installation check
jz increment_ah_and_return
;
; not installation. Check for cooked/raw netbios calls
;
cmp ah,1
je cooked
cmp ah,4
je cooked_or_raw
cmp ah,5
je get_adapter_resources
;DbgPrintString "Int2aHandler: unrecognized request: "
;DbgPrintHexWord ax
;DbgCrLf
;
; the call is not for us - chain to the next Int 2A handler
;
chain_next_handler:
DbgUnsupported
jmp Old2aHandler
cooked_or_raw:
or al,al ; ax = 0x0400?
jz cooked ; yes - cooked
cmp al,1 ; ax = 0x0401?
je raw ; yes - raw
cmp al,2 ; ax = 0x0402?
jne chain_next_handler ; yes - same as raw; no - chain next
;
; raw request: just call NetBios via INT 5C and set ah dependent upon whether
; an error was returned from NetBios
;
raw: int 5ch
sub ah,ah
or al,al
jz @f
increment_ah_and_return:
inc ah
@@: iret
get_adapter_resources:
mov ax,1
mov bx,16
mov cx,128
mov dx,64
iret
;
; 'cooked' call: this tries to convert synchronous NetBios calls to asynchronous
; then spins & beeps until the command has completed. Some commands are retried
; for a certain time or number of retries
;
;
; there is no justification for doing the 'cooked' processing that MINSES proper
; performs: The cooked processing is mainly to give the poor DOS user peace of
; mind when his machine seems dead, by occasionally beeping in a meaningful
; manner. Since we can terminate DOS sessions with impunity, there seems little
; point in letting the user know the machine is still alive, or retrying commands
; for that matter. However, that may change...
;
cooked:
DbgUnsupported
jmp short raw ; fudge it for now
Int2aHandler endp
ResidentCodeEnd
end