int2f.asm

开源DOS的C代码源程序

;
; File:
;                           int2f.asm
; Description:
;                 multiplex interrupt support code
;
;                    Copyright (c) 1996, 1998
;                       Pasquale J. Villani
;                       All Rights Reserved
;
; This file is part of DOS-C.
;
; DOS-C is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version
; 2, or (at your option) any later version.
;
; DOS-C is distributed in the hope that it will be useful, but
; WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
; the GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public
; License along with DOS-C; see the file COPYING.  If not,
; write to the Free Software Foundation, 675 Mass Ave,
; Cambridge, MA 02139, USA.
;
; $Id: int2f.asm,v 1.34 2004/05/04 10:16:45 bartoldeman Exp $
;

		%include "segs.inc"
        %include "stacks.inc"

segment	HMA_TEXT
            extern  _cu_psp:wrt DGROUP
            extern _syscall_MUX14

            extern _DGROUP_

                global  reloc_call_int2f_handler
reloc_call_int2f_handler:
                sti                             ; Enable interrupts
                cmp     ah,11h                  ; Network interrupt?
                jne     Int2f3                  ; No, continue
Int2f1:
                or      al,al                   ; Installation check?
                jz      FarTabRetn              ; yes, just return
Int2f2:
                mov ax,1                        ; TE 07/13/01
                                                ; at least for redirected INT21/5F44
                                                ; --> 2f/111e
                                                ; the error code is AX=0001 = unknown function
                stc
FarTabRetn:
                retf    2                       ; Return far
Int2f3:
                cmp     ah,16h
                je      FarTabRetn              ; Win Hook return fast
                cmp     ah,12h
                je      IntDosCal               ; Dos Internal calls

                cmp     ax,4a01h
                je      IntDosCal               ; Dos Internal calls
                cmp     ax,4a02h
                je      IntDosCal               ; Dos Internal calls
%ifdef WITHFAT32
                cmp     ax,4a33h                ; Check DOS version 7
                jne     Check4Share
                xor     ax,ax                   ; no undocumented shell strings
                iret
Check4Share:
%endif
                cmp     ah,10h                  ; SHARE.EXE interrupt?
                je      Int2f1                  ; yes, do installation check
                cmp     ah,08h
                je      DriverSysCal            ; DRIVER.SYS calls
                cmp     ah,14h                  ; NLSFUNC.EXE interrupt?
                jne     Int2f?iret              ; yes, do installation check
Int2f?14:      ;; MUX-14 -- NLSFUNC API
               ;; all functions are passed to syscall_MUX14
               push bp                 ; Preserve BP later on
               PUSH$ALL
               call _syscall_MUX14
               pop bp                  ; Discard incoming AX
               push ax                 ; Correct stack for POP$ALL
               POP$ALL
               mov bp, sp
               or ax, ax
               jnz Int2f?14?1          ; must return set carry
                   ;; -6 == -2 (CS), -2 (IP), -2 (flags)
                   ;; current SP = on old_BP
               and BYTE [bp-6], 0feh   ; clear carry as no error condition
               pop bp
               iret
Int2f?14?1:        or BYTE [bp-6], 1
               pop bp
Int2f?iret:
               iret

; DRIVER.SYS calls - now only 0803.
DriverSysCal:
                extern  _Dyn:wrt DGROUP
                cmp     al, 3
                jne     Int2f?iret
                mov     ds, [cs:_DGROUP_]
                mov     di, _Dyn+2
                jmp     short Int2f?iret


;***********************************************************
; internal doscalls INT2F/11xx - handled through C 
;***********************************************************
IntDosCal:                
                        ; set up register frame
;struct int2f12regs
;{
;  [space for 386 regs]
;  UWORD es,ds;
;  UWORD di,si,bp,bx,dx,cx,ax;
;  UWORD ip,cs,flags;
;  UWORD callerARG1; 
;}      
    push ax
    push cx
    push dx
    push bx
    push bp
    push si
    push di
    push ds
    push es

    cld

%if XCPU >= 386
  %ifdef WATCOM
    mov si,fs
    mov di,gs 
  %else 
    Protect386Registers    
  %endif
%endif          

    mov ds,[cs:_DGROUP_]
    extern   _int2F_12_handler
    call _int2F_12_handler

%if XCPU >= 386
  %ifdef WATCOM
    mov fs,si
    mov gs,di
  %else
    Restore386Registers    
  %endif
%endif      
    
    pop es
    pop ds
    pop di
    pop si
    pop bp
    pop bx
    pop dx
    pop cx
    pop ax
    
    iret

		global	SHARE_CHECK
SHARE_CHECK:
		mov	ax, 0x1000
		int	0x2f
		ret
           
;           DOS calls this to see if it's okay to open the file.
;           Returns a file_table entry number to use (>= 0) if okay
;           to open.  Otherwise returns < 0 and may generate a critical
;           error.  If < 0 is returned, it is the negated error return
;           code, so DOS simply negates this value and returns it in
;           AX.
; STATIC int share_open_check(char * filename,
;				/* pointer to fully qualified filename */
;                            unsigned short pspseg,
;				/* psp segment address of owner process */
;			     int openmode,
;				/* 0=read-only, 1=write-only, 2=read-write */
;			     int sharemode) /* SHARE_COMPAT, etc... */
		global SHARE_OPEN_CHECK
SHARE_OPEN_CHECK:
		mov	es, si		; save si
		pop	ax		; return address
		pop	dx		; sharemode;
		pop	cx		; openmode;
		pop	bx		; pspseg;
		pop	si		; filename
		push	ax		; return address
		mov	ax, 0x10a0
		int	0x2f	     	; returns ax
		mov	si, es		; restore si
		ret

;          DOS calls this to record the fact that it has successfully
;          closed a file, or the fact that the open for this file failed.
; STATIC void share_close_file(int fileno)  /* file_table entry number */

		global	SHARE_CLOSE_FILE
SHARE_CLOSE_FILE:
		pop	ax
		pop	bx
		push	ax
		mov	ax, 0x10a1
		int	0x2f
		ret

;          DOS calls this to determine whether it can access (read or
;          write) a specific section of a file.  We call it internally
;          from lock_unlock (only when locking) to see if any portion
;          of the requested region is already locked.  If pspseg is zero,
;          then it matches any pspseg in the lock table.  Otherwise, only
;          locks which DO NOT belong to pspseg will be considered.
;          Returns zero if okay to access or lock (no portion of the
;          region is already locked).  Otherwise returns non-zero and
;          generates a critical error (if allowcriter is non-zero).
;          If non-zero is returned, it is the negated return value for
;          the DOS call.
;STATIC int share_access_check(unsigned short pspseg,
;				/* psp segment address of owner process */
;                              int fileno,       /* file_table entry number */
;                              unsigned long ofs,        /* offset into file */
;                              unsigned long len,        /* length (in bytes) of region to access */
;                              int allowcriter)          /* allow a critical error to be generated */
		global SHARE_ACCESS_CHECK
SHARE_ACCESS_CHECK:
		mov	ax, 0x10a2
share_common:
		push	bp
		mov	bp, sp
		push	si
		push	di
		mov	bx, [bp + 16]	; pspseg
		mov	cx, [bp + 14]	; fileno
		mov	si, [bp + 12]	; high word of ofs
		mov	di, [bp + 10]	; low word of ofs
		les	dx, [bp + 6]	; len
		or	ax, [bp + 4]	; allowcriter/unlock
		int	0x2f
		pop	di
		pop	si
		pop	bp
		ret	14		; returns ax

;          DOS calls this to lock or unlock a specific section of a file.