v4.0/src/SELECT/ASM2C.ASM

   1 page    60,132                          ;AN000;
   2 name    asm2c                           ;AN000;
   3 title   Limited assembler to C interface;AN000;
   4 ;-------------------------------------------------------------------
   5 ;
   6 ;       MODULE:         asm2c
   7 ;
   8 ;       PURPOSE:
   9 ;               This routine is used as to map the assembly language
  10 ;               call made by xxx to a C language call.
  11 ;
  12 ;       INPUT:
  13 ;
  14 ;               ES:DI points to the buffer area where the table data
  15 ;               will be copied
  16 ;
  17 ;       CALLING FORMAT:
  18 ;
  19 ;       DATE:           7-16-87
  20 ;
  21 ;-------------------------------------------------------------------
  22
  23
  24         public  gget_status             ;AN000;
  25         public  asm2cInRegs             ;AN000;
  26         public  asm2coutregs            ;AN000;
  27         public  asm2csegregs            ;AN000;
  28
  29 _TEXT   segment byte public 'CODE'      ;AN000;
  30 _TEXT   ends                            ;AN000;
  31 _DATA   segment word public 'DATA'      ;AN000;
  32 _DATA   ends                            ;AN000;
  33 CONST   segment word public 'CONST'     ;AN000;
  34 CONST   ends                            ;AN000;
  35 _BSS    segment word public 'BSS'       ;AN000;
  36 _BSS    ends                            ;AN000;
  37 DGROUP  GROUP   CONST, _BSS, _DATA      ;AN000;
  38
  39 _DATA   segment word public 'DATA'      ;AN000;
  40
  41 ;-------------------------------------------------------------------
  42 ;       define an assembly language version of the C regs structure
  43 ;-------------------------------------------------------------------
  44
  45 asm2cInRegs     equ     $               ;AN000;
  46
  47 i_ax            dw      0               ;AN000;
  48 i_bx            dw      0               ;AN000;
  49 i_cx            dw      0               ;AN000;
  50 i_dx            dw      0               ;AN000;
  51 i_si            dw      0               ;AN000;
  52 i_di            dw      0               ;AN000;
  53 i_cflag         dw      0               ;AN000;
  54
  55 Asm2cOutRegs    equ     $               ;AN000;
  56
  57 o_ax            dw      0               ;AN000;
  58 o_bx            dw      0               ;AN000;
  59 o_cx            dw      0               ;AN000;
  60 o_dx            dw      0               ;AN000;
  61 o_si            dw      0               ;AN000;
  62 o_di            dw      0               ;AN000;
  63 o_cflag         dw      0               ;AN000;
  64
  65
  66 Asm2cSegRegs    equ     $               ;AN000;
  67 s_es            dw      0               ;AN000;
  68 s_cs            dw      0               ;AN000;
  69 s_ss            dw      0               ;AN000;
  70 s_ds            dw      0               ;AN000;
  71
  72         extrn   _end:far                ;AN000;
  73
  74 _DATA   ends                            ;AN000;
  75
  76 _TEXT   segment byte public 'CODE'      ;AN000;
  77
  78         extrn   _get_status:near        ;AN000;
  79
  80         ASSUME  CS: _TEXT               ;AN000;
  81         assume  ds: nothing             ;AN000;
  82         assume  es: nothing             ;AN000;
  83 ;-------------------------------------------------------------------
  84 ;-------------------------------------------------------------------
  85 page                                    ;AN000;
  86 ;-------------------------------------------------------------------
  87 ;       ggetstatus
  88 ;
  89 ;               This routine will reside in the C code segment
  90 ;
  91 ;-------------------------------------------------------------------
  92
  93 segment_of_dgroup       dw      seg dgroup;AN000;
  94
  95 SAVE_STACK      LABEL  DWORD            ;AN000;
  96 SAVE_SP         DW      0               ;AN000;
  97 SAVE_SS         DW      0               ;AN000;
  98
  99 SAVE_DS         DW      0               ;AN000;
 100 SAVE_ES         DW      0               ;AN000;
 101
 102 gget_status      proc    far            ;AN000;
 103
 104         MOV     SAVE_DS,DS              ;AN000;
 105         MOV     SAVE_ES,ES              ;AN000;
 106
 107         MOV     SAVE_SS,SS              ;AN000;
 108         MOV     SAVE_SP,SP              ;AN000;
 109
 110         mov     ss,segment_of_dgroup    ;AN000;
 111         add     sp,offset DGROUP:_end   ;AN000;
 112         ASSUME  SS: DGROUP              ;AN000;
 113
 114         MOV     DS,segment_of_dgroup    ;AN000;
 115         ASSUME  DS: DGROUP              ;AN000;
 116
 117 ;-------------------------------------------------------------------
 118 ;       set up InRegs
 119 ;-------------------------------------------------------------------
 120
 121         mov     i_ax,ax         ;AN000; make InRegs look like real registers
 122         mov     i_bx,bx         ;AN000;
 123         mov     i_cx,cx         ;AN000;
 124         mov     i_dx,dx         ;AN000;
 125         mov     i_si,si         ;AN000;
 126         mov     i_di,di         ;AN000;
 127
 128 ;-------------------------------------------------------------------
 129 ;       set up SegRegs
 130 ;-------------------------------------------------------------------
 131
 132         IRP     XX,<ES,SS,DS>   ;AN000;
 133         MOV     AX,SAVE_&XX     ;AN000;
 134         MOV     S_&XX,AX        ;AN000;
 135         ENDM                    ;AN000;
 136
 137         mov     s_cs,cs         ;AN000;
 138
 139 ;-------------------------------------------------------------------
 140 ;       put far pointers on stack
 141 ;-------------------------------------------------------------------
 142
 143 ;       push    ds              ; push far pointer to SegRegs
 144         lea     ax,DGROUP:Asm2cSegRegs;AN000;
 145         push    ax              ;AN000;
 146
 147 ;       push    ds              ; push far pointer to OutRegs
 148         lea     ax,DGROUP:Asm2cOutRegs;AN000;
 149         push    ax              ;AN000;
 150
 151 ;       push    ds              ; push far pointer to InRegs
 152         lea     ax,DGROUP:Asm2cInRegs;AN000;
 153         push    ax              ;AN000;
 154
 155 ;-------------------------------------------------------------------
 156         call    _get_status     ;AN000;
 157 ;-------------------------------------------------------------------
 158         add     sp,6            ;AN000;
 159 ;-------------------------------------------------------------------
 160 ;       set up real registers
 161 ;-------------------------------------------------------------------
 162
 163         mov     ax,o_ax         ;AN000; make real registers look like OutRegs
 164         mov     bx,o_bx         ;AN000;
 165         mov     cx,o_cx         ;AN000;
 166         mov     dx,o_dx         ;AN000;
 167         mov     si,o_si         ;AN000;
 168         mov     di,o_di         ;AN000;
 169
 170 ;-------------------------------------------------------------------
 171 ;       must remove the things we put on the stack
 172 ;-------------------------------------------------------------------
 173
 174         MOV     DS,SAVE_DS      ;AN000;
 175         MOV     ES,SAVE_ES      ;AN000;
 176         MOV     SS,SAVE_SS      ;AN000;
 177         MOV     SP,SAVE_SP      ;AN000;
 178
 179         ret                     ;AN000;
 180
 181
 182 gget_status      endp           ;AN000;
 183
 184 _TEXT   ends                    ;AN000; end code segment
 185
 186 ;-------------------------------------------------------------------
 187 ;-------------------------------------------------------------------
 188
 189
 190         end                     ;AN000;
 191