FreeCalypso > hg > freecalypso-sw
diff loadagent/libnosys/sbrk.c @ 1:da98dc08f575
loadagent: beginning to lay the foundation
author | Michael Spacefalcon <msokolov@ivan.Harhan.ORG> |
---|---|
date | Mon, 29 Apr 2013 03:21:00 +0000 |
parents | |
children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/loadagent/libnosys/sbrk.c Mon Apr 29 03:21:00 2013 +0000 @@ -0,0 +1,55 @@ +/* sbrk.c -- allocate memory dynamically. + * + * Copyright (c) 1995,1996 Cygnus Support + * + * The authors hereby grant permission to use, copy, modify, distribute, + * and license this software and its documentation for any purpose, provided + * that existing copyright notices are retained in all copies and that this + * notice is included verbatim in any distributions. No written agreement, + * license, or royalty fee is required for any of the authorized uses. + * Modifications to this software may be copyrighted by their authors + * and need not follow the licensing terms described here, provided that + * the new terms are clearly indicated on the first page of each file where + * they apply. + */ +#include <errno.h> +#include "glue.h" + +/* just in case, most boards have at least some memory */ +#ifndef RAMSIZE +# define RAMSIZE (caddr_t)0x100000 +#endif + +char *heap_ptr; + +/* + * sbrk -- changes heap size size. Get nbytes more + * RAM. We just increment a pointer in what's + * left of memory on the board. + */ +char * +_sbrk (nbytes) + int nbytes; +{ + char *base; + + if (!heap_ptr) + heap_ptr = (char *)&_end; + base = heap_ptr; + heap_ptr += nbytes; + + return base; +/* FIXME: We really want to make sure we don't run out of RAM, but this + * isn't very portable. + */ +#if 0 + if ((RAMSIZE - heap_ptr - nbytes) >= 0) { + base = heap_ptr; + heap_ptr += nbytes; + return (base); + } else { + errno = ENOMEM; + return ((char *)-1); + } +#endif +}