v4.0/src/MEMM/MEMM/ELIMFUNC.ASM

   1
   2
   3         page 58,132
   4 ;******************************************************************************
   5         title   ELIMFUNC - MEMM functions module
   6 ;******************************************************************************
   7 ;
   8 ;   (C) Copyright MICROSOFT Corp. 1986
   9 ;
  10 ;       Title:  MEMM.EXE - MICROSOFT Expanded Memory Manager 386 Driver
  11 ;
  12 ;       Module: ELIMFUNC - entry point for VDM functions
  13 ;
  14 ;       Version: 0.05
  15 ;
  16 ;       Date:   May 24,1986
  17 ;
  18 ;       Author:
  19 ;
  20 ;******************************************************************************
  21 ;
  22 ;       Change Log:
  23 ;
  24 ;       DATE     REVISION       Description
  25 ;       -------- --------       --------------------------------------------
  26 ;       04/24/86 Original       From EMML LIM driver.
  27 ;       06/28/86 0.02           Name change from MEMM386 to MEMM
  28 ;       07/05/86 0.04           Added segment R_CODE
  29 ;       07/06/86 0.04           Changed assume to DGROUP
  30 ;       07/10/86 0.05           jmp $+2 before "POPF"
  31 ;
  32 ;******************************************************************************
  33 ;   Functional Description:
  34 ;       This module contains the ON/OFF functionality code for activating/
  35 ;   deactivating EMM386 from DOS.  Functions in _TEXT to reduce code in
  36 ;   R_CODE segment.
  37 ;
  38 ;******************************************************************************
  39 .lfcond
  40 .386p
  41         page
  42 ;******************************************************************************
  43 ;                       P U B L I C   D E C L A R A T I O N S
  44 ;******************************************************************************
  45 ;
  46         public  ELIM_Entry
  47         public  EFunTab
  48         public  EFUN_CNT
  49 ;
  50         page
  51 ;******************************************************************************
  52 ;                       L O C A L   C O N S T A N T S
  53 ;******************************************************************************
  54 ;
  55         include vdmseg.inc
  56
  57 FALSE   equ     0
  58 TRUE    equ     not FALSE
  59
  60 ;******************************************************************************
  61 ;                       E X T E R N A L    R E F E R E N C E S
  62 ;******************************************************************************
  63 ;
  64 _DATA   segment
  65         extrn   Active_Status:byte
  66         extrn   Auto_Mode:byte
  67 _DATA   ends
  68
  69 _TEXT   segment
  70         extrn   _AutoUpdate:near        ; update auto mode status
  71         extrn   GoVirtual:near
  72         extrn   RRProc:near             ; Return processor to real mode(RRTrap)
  73 _TEXT   ends
  74
  75         page
  76 ;******************************************************************************
  77 ;                       S E G M E N T   D E F I N I T I O N
  78 ;******************************************************************************
  79 ;
  80 ;******************************************************************************
  81 ;
  82 ;       Code Segment R_CODE
  83 ;
  84 ;******************************************************************************
  85 ;
  86 R_CODE  segment
  87         assume  cs:R_CODE, ds:DGROUP, es:DGROUP
  88 ;
  89 ;       ELIM functions table    - far calls
  90 ;
  91 EFunTab label   dword
  92         dw      offset  E_GetStatus
  93         dw      seg     _TEXT
  94
  95         dw      offset  E_ONOFF
  96         dw      seg     _TEXT
  97
  98 EFUN_CNT        equ     ($-EFunTab)/4
  99
 100         page
 101 ;******************************************************************************
 102 ;       ELIM_Entry - entry point for general ELIM functions
 103 ;
 104 ;       THIS IS A FAR CALL ROUTINE
 105 ;
 106 ;       ENTRY:  REAL or VIRTUAL mode only
 107 ;               AH = 0  => get current status of VDM/EMM386
 108 ;               AH = 1  => ON/OFF/AUTO
 109 ;
 110 ;       EXIT: EMM386 is activated/deactivated if possible
 111 ;             NC => no errors.
 112 ;             CY => ERROR occured.
 113 ;                       AH = error number
 114 ;                       AH= 01 =>invalid function.
 115 ;
 116 ;       USED: none
 117 ;
 118 ;******************************************************************************
 119 ELIM_Entry      proc    far
 120 ;
 121         push    bx
 122         push    ds
 123 ;
 124         mov     bx,seg DGROUP
 125         mov     ds,bx
 126 ;
 127         cmp     ah,EFUN_CNT     ;Q: valid function #
 128         jae     EE_inv_func     ;  N: return error
 129         xor     bx,bx           ;  Y: exec function
 130         mov     bl,ah           ; bx = function #
 131         shl     bx,2            ; dword index
 132         call    CS:EFunTab[bx]  ; call the function
 133 ;
 134 EE_exit:
 135         pop     ds
 136         pop     bx
 137         ret
 138 ;
 139 EE_inv_func:
 140         mov     ah,01
 141         stc
 142         jmp     short EE_exit
 143 ;
 144 ELIM_Entry      endp
 145
 146 R_CODE  ends
 147
 148         page
 149 ;******************************************************************************
 150 ;
 151 ;       Code Segment _TEXT
 152 ;
 153 ;******************************************************************************
 154 _TEXT   segment
 155         assume  cs:_TEXT, ds:DGROUP, es:DGROUP
 156
 157 ;******************************************************************************
 158 ;       E_GetStatus - get ELIM/VDM status
 159 ;
 160 ;       ENTRY:  AH = 0
 161 ;               DS = DGROUP
 162 ;
 163 ;       EXIT:   AH = 0 => ELIM ON
 164 ;                  = 1 => ELIM OFF
 165 ;                  = 2 => ELIM in AUTO mode (ON)
 166 ;                  = 3 => ELIM in AUTO mode (OFF)
 167 ;
 168 ;       USED: none
 169 ;
 170 ;******************************************************************************
 171 E_GetStatus     proc    far
 172 ;
 173         xor     ah,ah                   ; init to on
 174         cmp     [Auto_Mode],0           ; Q: auto mode ?
 175         je      not_auto                ; N: try on/off
 176         mov     ah,2                    ; Y: indicate as such
 177 not_auto:
 178         cmp     [Active_Status],0       ;Q: is ELIM active ?
 179         jne     EGS_exit                ;  Y: exit with status = 0/2
 180         inc     ah                      ;  N: exit with status = 1/3
 181 EGS_exit:
 182         ret
 183 ;
 184 E_GetStatus     endp
 185
 186 ;******************************************************************************
 187 ;       E_ONOFF  - general ON/OFF code for ELIM
 188 ;
 189 ;       ENTRY:  AH = 1
 190 ;                AL = 0 => ON
 191 ;                AL = 1 => OFF
 192 ;                AL = 2 => AUTO
 193 ;               DS = DGROUP
 194 ;
 195 ;       EXIT:   Virtual mode and ELIM ON
 196 ;               OR Real mode and ELIM OFF
 197 ;
 198 ;       USED: none
 199 ;
 200 ;******************************************************************************
 201 E_ONOFF proc    far
 202 ;
 203         cmp     al,0                    ;Q: turn it on ?
 204         jne     EOO_OFF                 ;  N: check for OFF/AUTO
 205         cmp     [Active_Status],0       ;  Y: Q: is it already active ?
 206         jne     EOO_AUTO_OFF            ;       Y: then just leave
 207         mov     [Active_Status],1       ;       N: then go to virtual mode
 208         mov     [Auto_Mode],0           ;       and clear auto mode
 209         call    GoVirtual
 210         jmp     short EOO_OK
 211 EOO_OFF:
 212         cmp     al,1                    ;Q: turn it off ?
 213         jne     EOO_AUTO                ;  N: check for AUTO mode
 214
 215 ;
 216 ; we are not providing the ability to turn emm off.
 217 ;
 218 ;        cmp     [Active_Status],0       ;  Y: Q: is it already OFF ?
 219 ;        je      EOO_AUTO_OFF            ;       Y: then just leave
 220 ;        mov     [Active_Status],0       ;       N: then go to real mode
 221 ;        mov     [Auto_Mode],0           ;       and clear auto mode
 222 ;        call    RRProc                  ; put processor in real mode
 223 ;        jmp     short EOO_OK
 224
 225          jmp    short EOO_inv
 226
 227
 228 EOO_AUTO_OFF:
 229 ;        cmp     [Auto_Mode],0           ; q: auto mode already off?
 230 ;        jz      EOO_OK                  ; y: forget it
 231 ;        mov     [Auto_Mode],0           ; n: clear it
 232 ;        jmp     short EOO_OK            ; and update status
 233
 234          jmp    short EOO_inv
 235
 236
 237 EOO_AUTO:
 238          cmp     al,2                    ;Q: go to auto mode ?
 239          jne     EOO_inv                 ;  N: invalid function
 240 ;        cmp     [Auto_Mode],0           ;  Y: Q: is it already in auto mode
 241 ;        jne     EOO_OK                  ;       Y: then just leave
 242 ;        mov     [Auto_Mode],1           ;       N: then go to auto mode
 243 ;        call    _AutoUpdate             ;
 244
 245          jmp    short EOO_inv
 246 ;
 247 ;   leave with no errors
 248 ;
 249 EOO_OK:
 250         clc
 251
 252 EOO_exit:
 253         ret
 254 ;
 255 ;  invalide ON/OFF/AUTO function call
 256 ;
 257 EOO_inv:
 258         mov     ah,1
 259         stc
 260         jmp     short EOO_exit
 261 ;
 262 E_ONOFF endp
 263
 264 ;
 265 _TEXT   ends
 266
 267         end
 268 \1a