Re: Problem with fasm

suchi_01 wrote:
> Hi All,
>                   There is a complicated issue here. I have downloaded
> fasm source of a driver and want to integrate it to my kernel.
> However, there is a problem:
> 
> 1. If i call a FASM function from within C code (kernel), it is not
> able to return back to the next line in C Code

What *does* it do?

> 2. If i call a NASM function from within C Code, it works properly (it
> returns back to next line in C Code)
> 
> Here are the code snippets:
> 
> NASM:
> 
> global <func name>
> 
> <func name>:
>              ret
> 
> 
> FASM:
> 
> public <func name>
> 
> <func name>:
>           ret
> 
> 
> Is there a global keyword or similar stuff in FASM?

"public", AFAIK. We need to tell Fasm a "format", too (in the source, 
not on the command line like Nasm). As a test, I just "converted" a Nasm 
demo I had to Fasm (just added "format elf", changed "global" to 
"public" and fixed up the section declaration). Worked fine. The only 
issue I can see is that I don't think Fasm sup****ts OMF. What format are 
you using?

Best,
Frank

;---------------
format elf

public getvendor

section ".text" executable
getvendor:
     pusha
     xor eax, eax
     cpuid
     mov eax, [esp + 36]
     mov [eax], ebx
     mov [eax + 4], edx
     mov [eax + 8], ecx
     mov byte [eax + 12], 0
     popa
     xor eax, eax
     ret
;-----------------

And the C caller...

#include <stdio.h>

void getvendor(char *vendorbuf);

int main(void)
  {char vendorbuf[13];
   getvendor(vendorbuf);

   puts(vendorbuf);
   return 0;
  }