From: eplmst AT lu DOT erisoft DOT se (Martin Stromberg)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: AT&T inline asm in DJGPP...
Date: 1 Dec 2002 13:36:38 GMT
Organization: Ericsson Erisoft AB, Sweden
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lewi9908 (lewi9908 AT ghc DOT ctc DOT edu) wrote:
: I am am working on the mix ASM/C model and here is my current try...

: Ker.asm
: [BITS 32]

:  global _OutputText

: _OutputText:

...

: And here is the ker.cpp

: extern void OutputText(char* pOutStr, int iVideoMemIndex);

: int main()
: {
:     OutputText("Hello, world!", 22);

:     return 0;

: }

: Now the problems...

: 1) When linking I get an error - "...undefined reference to
: '_OutputText(char* , int);". Now I am new to global/extern so I don't know
: what is wrong...

Name ker.cpp ker.c. Otherwise you'll have C++ name mangling. Or
declare OutputText as "extern C".

: 2) Next in the lines...

: StartLoop:
:  and byte ptr [edx], 0x0                  ;Check for Null char
:  jz PrintDone
:  mov byte ptr [ebx], byte ptr [edx]
:  add byte ptr [ebx], 0x1
...
: PrintDone:

: every mov, and(the instruction), and(the conjuction) add line gives me an
: error -"...comma or end of line expected" now I don't know what I did wrong
: there either...

I'm not sure which assembler you use. But what about "and byte [edx],
0x0" or "and [ byte edx ], 0x0"?

Some other observations: 

Doesn't the code above zero [edx] and (if jump not taken) loads [ebx]
with [edx] which is zero and then add one to it? (But I might have
mixed up source and destination.) If so, then why not "mov byte [ebx],
0x1"?

mov (memory reference), (memory reference) isn't allowed on IA32.


Right,

						MartinS