1 files changed, 157 insertions, 0 deletions
diff --git a/src/roms/SLOF/lib/libc/stdlib/malloc.c b/src/roms/SLOF/lib/libc/stdlib/malloc.c
new file mode 100644
index 0000000..b2a3138
--- /dev/null
+++ b/src/roms/SLOF/lib/libc/stdlib/malloc.c
@@ -0,0 +1,157 @@
+/******************************************************************************
+ * Copyright (c) 2004, 2008 IBM Corporation
+ * All rights reserved.
+ * This program and the accompanying materials
+ * are made available under the terms of the BSD License
+ * which accompanies this distribution, and is available at
+ * http://www.opensource.org/licenses/bsd-license.php
+ *
+ * Contributors:
+ *     IBM Corporation - initial implementation
+ *****************************************************************************/
+
+
+#include "stddef.h"
+#include "stdlib.h"
+#include "unistd.h"
+#include "malloc_defs.h"
+
+
+static int clean(void);
+
+
+/* act points to the end of the initialized heap and the start of uninitialized heap */
+static char *act;
+
+/* Pointers to start and end of heap: */
+static char *heap_start, *heap_end;
+
+
+/*
+ * Standard malloc function
+ */
+void *
+malloc(size_t size)
+{
+	char *header;
+	void *data;
+	size_t blksize;         /* size of memory block including the chunk */
+
+	blksize = size + sizeof(struct chunk);
+
+	/* has malloc been called for the first time? */
+	if (act == 0) {
+		size_t initsize;
+		/* add some space so we have a good initial playground */
+		initsize = (blksize + 0x1000) & ~0x0fff;
+		/* get initial memory region with sbrk() */
+		heap_start = sbrk(initsize);
+		if (heap_start == (void*)-1)
+			return NULL;
+		heap_end = heap_start + initsize;
+		act = heap_start;
+	}
+
+	header = act;
+	data = act + sizeof(struct chunk);
+
+	/* Check if there is space left in the uninitialized part of the heap */
+	if (act + blksize > heap_end) {
+		//search at begin of heap
+		header = heap_start;
+
+		while ((((struct chunk *) header)->inuse != 0
+		        || ((struct chunk *) header)->length < size)
+		       && header < act) {
+			header = header + sizeof(struct chunk)
+			         + ((struct chunk *) header)->length;
+		}
+
+		// check if heap is full
+		if (header >= act) {
+			if (clean()) {
+				// merging of free blocks succeeded, so try again
+				return malloc(size);
+			} else if (sbrk(blksize) == heap_end) {
+				// succeeded to get more memory, so try again
+				heap_end += blksize;
+				return malloc(size);
+			} else {
+				// No more memory available
+				return 0;
+			}
+		}
+
+		// Check if we need to split this memory block into two
+		if (((struct chunk *) header)->length > blksize) {
+			//available memory is too big
+			int alt;
+
+			alt = ((struct chunk *) header)->length;
+			((struct chunk *) header)->inuse = 1;
+			((struct chunk *) header)->length = size;
+			data = header + sizeof(struct chunk);
+
+			//mark the rest of the heap
+			header = data + size;
+			((struct chunk *) header)->inuse = 0;
+			((struct chunk *) header)->length =
+			    alt - blksize;
+		} else {
+			//new memory matched exactly in available memory
+			((struct chunk *) header)->inuse = 1;
+			data = header + sizeof(struct chunk);
+		}
+
+	} else {
+
+		((struct chunk *) header)->inuse = 1;
+		((struct chunk *) header)->length = size;
+
+		act += blksize;
+	}
+
+	return data;
+}
+
+
+/*
+ * Merge free memory blocks in initialized heap if possible
+ */
+static int
+clean(void)
+{
+	char *header;
+	char *firstfree = 0;
+	char check = 0;
+
+	header = heap_start;
+	//if (act == 0)		// This should never happen
+	//	act = heap_end;
+
+	while (header < act) {
+
+		if (((struct chunk *) header)->inuse == 0) {
+			if (firstfree == 0) {
+				/* First free block in a row, only save address */
+				firstfree = header;
+
+			} else {
+				/* more than one free block in a row, merge them! */
+				((struct chunk *) firstfree)->length +=
+				    ((struct chunk *) header)->length +
+				    sizeof(struct chunk);
+				check = 1;
+			}
+		} else {
+			firstfree = 0;
+
+		}
+
+		header = header + sizeof(struct chunk)
+		         + ((struct chunk *) header)->length;
+
+	}
+
+	return check;
+}