1 files changed, 62 insertions, 0 deletions
diff --git a/lib/libstand/sbrk.c b/lib/libstand/sbrk.c
new file mode 100644
index 0000000..93d94e4
--- /dev/null
+++ b/lib/libstand/sbrk.c
@@ -0,0 +1,62 @@
+/*-
+ * Copyright (c) 1998 Michael Smith
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * Minimal sbrk() emulation required for malloc support.
+ */
+
+#include <string.h>
+#include "stand.h"
+
+static size_t	maxheap, heapsize = 0;
+static void	*heapbase;
+
+void
+setheap(void *base, void *top)
+{
+    /* Align start address to 16 bytes for the malloc code. Sigh. */
+    heapbase = (void *)(((uintptr_t)base + 15) & ~15);
+    maxheap = (char *)top - (char *)heapbase;
+}
+
+char *
+sbrk(int incr)
+{
+    char	*ret;
+    
+    if ((heapsize + incr) <= maxheap) {
+	ret = (char *)heapbase + heapsize;
+	bzero(ret, incr);
+	heapsize += incr;
+	return(ret);
+    }
+    errno = ENOMEM;
+    return((char *)-1);
+}
+