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-rw-r--r--qemu/roms/SLOF/lib/libc/stdlib/malloc.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/qemu/roms/SLOF/lib/libc/stdlib/malloc.c b/qemu/roms/SLOF/lib/libc/stdlib/malloc.c
new file mode 100644
index 000000000..b2a3138eb
--- /dev/null
+++ b/qemu/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;
+}