SMALL Model

LOC    OBJ         LINE     SOURCE

                      1     $CASE ; make CASE sensitive for C interface
                      2
                      3                     NAME A251_MODULE
                      4
                      5     ; /***********************************/
                      6     ; /* Sample Assembler to C Interface */
                      7     ; /***********************************/
                      8     ;
                      9     ; extern char func1 (int a1, char a2, bit b);
                     10     ;
                     11     ; extern bit flag;
                     12     ; extern char val;
                     13     ;
                     14     ; int func2 (int *ip, char *cp)  {
                     15     ;   char c;
                     16     ;
                     17     ;   c = func1 (*ip, *cp, flag);
                     18     ;   val += c;
                     19     ;   return (val);
                     20     ; }
                     21
                     22
                     23     EXTRN  BIT        (flag)
                     24     EXTRN  DATA :BYTE (val)
                     25     EXTRN  CODE :NEAR (func1)
                     26     EXTRN  BIT        (?func1?BIT)
                     27
------               28     ?PR?FUNC2?ASM1  SEGMENT  CODE
                     29
                     30     PUBLIC func2  ; entry point for func2
                     31
------               32             RSEG       ?PR?FUNC2?ASM1
                     33     func2 PROC NEAR
                     34     ; Variable 'cp' is passed in Register 'DR4'
                     35     ; Variable 'ip' is passed in Register 'DR0'
                     36
                     37     ; func1 is called with parameters
                     38     ; copy flag to parameter area
                     39     ; all other parameters are passed in registers
000000 A200       E  40             MOV      C,flag
000002 9200       E  41             MOV      ?func1?BIT,C
000004 7E1BB0        42             MOV      R11,@DR4
000007 0B0A30        43             MOV      WR6,@DR0
00000A 120000     E  44             LCALL    func1
                     45     ; func1 returns a character in R11 (same as A)
00000D 2500       E  46             ADD      A,val
00000F F500       E  47             MOV      val,A
                     48     ; func2 returns a integer in WR6
000011 1A3B          49             MOVS     WR6,R11
000013 22            50             RET
                     51             ENDP
                     52
                     53             END