20000317 sourceware import

libgloss/sbrk.c

@@ -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
+}