[syslinux] Syslinux malloc

[Murali Krishnan Ganapathy]

TenThumbs wrote:

> I mentioned in a private email recently that it would be useful if 
> syslinux
> had a malloc implementation. I have one now if anyone's interested.
>  
>
I just implemented a simple malloc for a 16-bit COMBOOT application. I 
will surely be interested in seeing your implementation. We should 
probably starting building an implementation of all useful C routines.

Ideally, we should be able to create an include file "comboot.h", which 
declares all the useful C routines, and defines them to generate an 
error message. That way one can use any of the C libraries as long as 
they include comboot.h as well. If the C function cannot work under 
comboot, then there will be an error generated.

Here is a small example.

/* COMBOOT.H starts */

#define fopen 1=7
#define fclose 1=7
....

#include "heap.h"
#include "string.h"

extern void * malloc(unsigned int );
extern void * memset(void *, char, unsigned int);
....
// COMBOOT.H ends

Now any C file which includes comboot.h cannot use fopen (it will result 
in a compile error).
If one includes <stdlib.h> and tries to use malloc, then there will be 
two implementations and will result in a linker error.
This will be useful till we have mini libc, one can use for comboot coding.

BTW, how mature is klibc to use for this?

- Murali