1 files changed, 50 insertions, 0 deletions
diff --git a/hw/bsp/stm32f4discovery/src/sbrk.c b/hw/bsp/stm32f4discovery/src/sbrk.c
new file mode 100644
index 00000000..e95a5d7a
--- /dev/null
+++ b/hw/bsp/stm32f4discovery/src/sbrk.c
@@ -0,0 +1,50 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+extern char __HeapBase;
+extern char __HeapLimit;
+
+void *
+_sbrk(int incr)
+{
+    static char *brk = &__HeapBase;
+
+    void *prev_brk;
+
+    if (incr < 0) {
+        /* Returning memory to the heap. */
+        incr = -incr;
+        if (brk - incr < &__HeapBase) {
+            prev_brk = (void *)-1;
+        } else {
+            prev_brk = brk;
+            brk -= incr;
+        }
+    } else {
+        /* Allocating memory from the heap. */
+        if (&__HeapLimit - brk >= incr) {
+            prev_brk = brk;
+            brk += incr;
+        } else {
+            prev_brk = (void *)-1;
+        }
+    }
+
+    return prev_brk;
+}