if_vtnet - Default to link up, when VIRTIO_NET_F_STATUS is not negotiated.
[dragonfly.git] / lib / libstand / sbrk.c
blob7c61a67dbb2712d1e7aed275da4f50dea05e0580
1 /*-
2 * Copyright (c) 1998 Michael Smith
3 * All rights reserved.
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.
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.
26 * $FreeBSD: src/lib/libstand/sbrk.c,v 1.2.2.1 2000/05/18 08:00:57 ps Exp $
30 * Minimal sbrk() emulation required for malloc support.
33 #include <string.h>
34 #include "stand.h"
36 static size_t maxheap, heapsize = 0;
37 static void *sbrkbase;
39 void
40 setheap(void *base, void *top)
42 /* Align start address to 16 bytes for the malloc code. Sigh. */
43 sbrkbase = (void *)(((uintptr_t)base + 15) & ~15);
44 maxheap = top - sbrkbase;
47 char *
48 getheap(size_t *sizep)
50 *sizep = maxheap;
51 return sbrkbase;
54 char *
55 sbrk(intptr_t incr)
57 char *ret;
59 if ((heapsize + incr) <= maxheap) {
60 ret = sbrkbase + heapsize;
61 bzero(ret, incr);
62 heapsize += incr;
63 return(ret);
65 errno = ENOMEM;
66 return((char *)-1);