apisupt.lst

来自「DOS SOURCE CODE,DOS-C started in 1988 as」· LST 代码 · 共 221 行

Turbo Assembler	 Version 3.1	    04/11/13 12:54:49	    Page 1
APISUPT.ASM



      1				     ; File:
      2				     ;			       apisupt.asm
      3				     ; Description:
      4				     ;	   Assembly support routines for stack manipulation, etc.
      5				     ;
      6				     ;			     Copyright (c) 1995
      7				     ;			     Pasquale J. Villani
      8				     ;			     All Rights	Reserved
      9				     ;
     10				     ; This file is part of DOS-C.
     11				     ;
     12				     ; DOS-C is	free software; you can redistribute it and/or
     13				     ; modify it under the terms of the	GNU General Public License
     14				     ; as published by the Free	Software Foundation; either version
     15				     ; 2, or (at your option) any later	version.
     16				     ;
     17				     ; DOS-C is	distributed in the hope	that it	will be	useful,	but
     18				     ; WITHOUT ANY WARRANTY; without even the implied warranty of
     19				     ; MERCHANTABILITY or FITNESS FOR A	PARTICULAR PURPOSE.  See
     20				     ; the GNU General Public License for more details.
     21				     ;
     22				     ; You should have received	a copy of the GNU General Public
     23				     ; License along with DOS-C; see the file COPYING.	If not,
     24				     ; write to	the Free Software Foundation, 675 Mass Ave,
     25				     ; Cambridge, MA 02139, USA.
     26				     ;
     27				     ; $Logfile:   C:/dos-c/src/kernel/apisupt.asv  $
     28				     ;
     29				     ; $Header:	  C:/dos-c/src/kernel/apisupt.asv   1.3	  16 Jan 1997 12:46:44	 patv  $
     30				     ;
     31				     ; $Log:   C:/dos-c/src/kernel/apisupt.asv	$
     32				     ;
     33				     ;	 Rev 1.3   16 Jan 1997 12:46:44	  patv
     34				     ;pre-Release 0.92 feature additions
     35				     ;
     36				     ;	 Rev 1.2   29 May 1996 21:03:38	  patv
     37				     ;bug fixes	for v0.91a
     38				     ;
     39				     ;	 Rev 1.1   01 Sep 1995 17:54:26	  patv
     40				     ;First GPL	release.
     41				     ;
     42				     ;	 Rev 1.0   02 Jul 1995	9:04:50	  patv
     43				     ;Initial revision.
     44				     ;
     45
     46
     47	0000			     _TEXT	     segment byte public 'CODE'
     48				     DGROUP	     group   _DATA,_BSS,_BSSEND		     ; small model
     49						     assume  cs:_TEXT,ds:DGROUP,ss:DGROUP
     50	0000			     _TEXT	     ends
     51
     52	0000			     _DATA	     segment word public 'DATA'
     53	0000			     _DATA	     ends
     54
     55	0000			     _BSS	     segment word public 'BSS'
Turbo Assembler	 Version 3.1	    04/11/13 12:54:49	    Page 2
APISUPT.ASM



     56	0000			     _BSS	     ends
     57
     58	0000			     _BSSEND	     segment byte public 'STACK'
     59	0000			     _BSSEND	     ends
     60
     61
     62						     extrn   _api_sp:word	     ; api stacks - for	context
     63						     extrn   _api_ss:word	     ; switching
     64						     extrn   _usr_sp:word	     ; user stacks
     65						     extrn   _usr_ss:word
     66
     67	0000			     _TEXT	     segment
     68						     assume  cs: _TEXT
     69						     public  _set_stack
     70				     ;
     71				     ; void far	set_stack(void)	-
     72				     ;	     save current stack	and setup our local stack
     73				     ;
     74	0000			     _set_stack	     proc    far
     75
     76						     ; save foreground stack
     77
     78						     ; we need to get the return values	from the stack
     79						     ; since the current stack will change
     80	0000  58				     pop     ax			     ;get return offset
     81	0001  5B				     pop     bx			     ;get return segment
     82
     83						     ; Save the	flags so that we can restore correct interrupt
     84						     ; state later. We need to disable interrupts so that we
     85						     ; don't trash memory with new sp-old ss combination
     86	0002  9C				     pushf
     87	0003  5A				     pop     dx
     88	0004  FA				     cli
     89
     90						     ; save bp
     91	0005  55				     push    bp
     92
     93	0006  8B CC				     mov     cx, sp
     94	0008  F7 D9				     neg     cx
     95
     96						     ; save away foreground process' stack
     97	000A  FF 36 0000e			     push    word ptr DGROUP:_usr_ss
     98	000E  FF 36 0000e			     push    word ptr DGROUP:_usr_sp
     99
    100	0012  8C 16 0000e			     mov     word ptr DGROUP:_usr_ss,ss
    101	0016  89 26 0000e			     mov     word ptr DGROUP:_usr_sp,sp
    102
    103						     ; setup our local stack
    104	001A  8E 16 0000e			     mov     ss,word ptr DGROUP:_api_ss
    105	001E  8B 26 0000e			     mov     sp,word ptr DGROUP:_api_sp
    106
    107	0022  03 CC				     add     cx, sp
    108	0024  03 E9				     add     bp, cx
    109
    110						     ; setup for ret
Turbo Assembler	 Version 3.1	    04/11/13 12:54:49	    Page 3
APISUPT.ASM



    111	0026  53				     push    bx
    112	0027  50				     push    ax
    113
    114						     ; now restore interrupt state
    115	0028  52				     push    dx
    116	0029  9D				     popf
    117
    118	002A  CB				     ret
    119
    120	002B			     _set_stack	     endp
    121
    122				     ;
    123				     ; void far	restore_stack(void) -
    124				     ;	     restore foreground	stack, throw ours away
    125				     ;
    126						     public  _restore_stack
    127	002B			     _restore_stack  proc    far
    128
    129					     ; we need to get the return values	from the stack
    130					     ; since the current stack will change
    131	002B  59				     pop     cx			     ;get return offset
    132	002C  5B				     pop     bx			     ;get return segment
    133
    134						     ; Save the	flags so that we can restore correct interrupt
    135						     ; state later. We need to disable interrupts so that we
    136						     ; don't trash memory with new sp-old ss combination
    137	002D  9C				     pushf
    138	002E  5A				     pop     dx
    139	002F  FA				     cli
    140
    141						     ; save background stack
    142	0030  8C 16 0000e			     mov     word ptr DGROUP:_api_ss,ss
    143	0034  89 26 0000e			     mov     word ptr DGROUP:_api_sp,sp
    144
    145						     ; restore foreground stack	here
    146	0038  8E 16 0000e			     mov     ss,word ptr DGROUP:_usr_ss
    147	003C  8B 26 0000e			     mov     sp,word ptr DGROUP:_usr_sp
    148
    149	0040  8F 06 0000e			     pop     word ptr DGROUP:_usr_sp
    150	0044  8F 06 0000e			     pop     word ptr DGROUP:_usr_ss
    151
    152						     ; make bp relative	to our stack frame
    153	0048  5D				     pop     bp
    154						     ;mov     bp,sp
    155
    156						     ; setup for ret
    157	0049  53				     push    bx
    158	004A  51				     push    cx
    159
    160						     ; now restore interrupt state
    161	004B  52				     push    dx
    162	004C  9D				     popf
    163
    164	004D  CB				     ret
    165	004E			     _restore_stack  endp
Turbo Assembler	 Version 3.1	    04/11/13 12:54:49	    Page 4
APISUPT.ASM



    166
    167	004E			     _TEXT	     ends
    168
    169						     end
Turbo Assembler	 Version 3.1	    04/11/13 12:54:49	    Page 5
Symbol Table




Symbol Name			  Type	 Value

??DATE				  Text	 "04/11/13"
??FILENAME			  Text	 "APISUPT "
??TIME				  Text	 "12:54:49"
??VERSION			  Number 030A
@CPU				  Text	 0101H
@CURSEG				  Text	 _TEXT
@FILENAME			  Text	 APISUPT
@WORDSIZE			  Text	 2
STANDALONE			  Text	 1
_API_SP	(_api_sp)		  Word	 ----:---- Extern
_API_SS	(_api_ss)		  Word	 ----:---- Extern
_RESTORE_STACK (_restore_stack)	  Far	 _TEXT:002B
_SET_STACK (_set_stack)		  Far	 _TEXT:0000
_USR_SP	(_usr_sp)		  Word	 ----:---- Extern
_USR_SS	(_usr_ss)		  Word	 ----:---- Extern

Groups & Segments		  Bit Size Align  Combine Class

DGROUP				  Group
  _BSS				  16  0000 Word	  Public  BSS
  _BSSEND			  16  0000 Byte	  Public  STACK
  _DATA				  16  0000 Word	  Public  DATA
_TEXT				  16  004E Byte	  Public  CODE