sbrk.c

来自「guide and some example with visualC++」· C语言 代码 · 共 39 行

/* sbrk.c -- allocate memory dynamically.
 * 
 * Copyright (c) 1995 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"

#define RAMSIZE             (caddr_t)0x80000
/*
 * 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;
{
  static long heap_ptr=_end; 
  char  *base;
  #ifdef debuglg
  prs("[sbrk]\n");
  #endif
  
  base = heap_ptr;
  heap_ptr += nbytes;
  
  return base;
}