1 /*- 2 * Copyright (c) 1998 Michael Smith 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 /* 29 * Minimal sbrk() emulation required for malloc support. 30 */ 31 32 #include <string.h> 33 #include "stand.h" 34 #include "zalloc_defs.h" 35 36 static size_t maxheap, heapsize = 0; 37 static void *heapbase; 38 39 void 40 setheap(void *base, void *top) 41 { 42 /* Align start address for the malloc code. Sigh. */ 43 heapbase = (void *)(((uintptr_t)base + MALLOCALIGN_MASK) & 44 ~MALLOCALIGN_MASK); 45 maxheap = (char *)top - (char *)heapbase; 46 } 47 48 char * 49 sbrk(int incr) 50 { 51 char *ret; 52 53 if (heapbase == 0) 54 panic("No heap setup"); 55 56 if ((heapsize + incr) <= maxheap) { 57 ret = (char *)heapbase + heapsize; 58 bzero(ret, incr); 59 heapsize += incr; 60 return(ret); 61 } 62 errno = ENOMEM; 63 return((char *)-1); 64 } 65 66