🚀 go-pugleaf

In <1992Sep2.1478.12907@dosgate> "gord armstrong" <gord.armstrong@canrem.com> writes:


>Segments ARRRG!

>'C' Compiler: Microsoft C 6.0, Assembler: TASM 2.0

>I'm linking a 'C' and assembler prog together in DOS, and I need
>to pass a pointer from a C prog to an assembler proc. For a SMALL
>model this is not much of a problem since code and data are in the
>same segment, as follows:

>  char *ptr; // will use in other modules, make it global

>main()
>{
>  ptr=malloc((unsigned int)1024); *ptr=0x55;
>  get_value();  // call ass'y routine
>  free(ptr);
>}


I don't have TASM, so I can't confirm but the corresponding (correct) MASM
code would be.

MSC 5.1 puts unintialized variables in large model in FAR_BSS, so you might
use that rather than FARDATA, but why bother?

DOSSEG
.MODEL LARGE
                public  _get_value:proc

                extrn   _ptr:dword

.DATA
other_var       db      ?
.CODE
;--------------------------------------------------------
; _get_value
;--------------------------------------------------------
_get_value      proc

                mov     ax,SEG _ptr 
                mov     es,ax
                assume  es,SEG _ptr
                les     bx,es:_ptr
                assume  es,nothing   
                mov     al,es:[bx]
                xor     ah,ah
                call    to_integer

                ret
_get_value      endp

--
Arthur L. Rubin: a_rubin@dsg4.dse.beckman.com (work) Beckman Instruments/Brea
216-5888@mcimail.com 70707.453@compuserve.com arthur@pnet01.cts.com (personal)
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