fdt: Align the start of the livetree
Ensure that the block of memory used by live tree is aligned according to
the default for structures. This ensures that the root node appears at
the start of the block, so it can be used with free(), rather than being
4 bytes later in some cases.
This corrects a rather obscure bug in unflatten_device_tree().
Fixes: 8b50d526ea5 ("dm: Add a function to create a 'live' device tree")
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/of_live.c b/lib/of_live.c
index 1b5964d..05588d5 100644
--- a/lib/of_live.c
+++ b/lib/of_live.c
@@ -287,9 +287,12 @@
debug(" size is %lx, allocating...\n", size);
/* Allocate memory for the expanded device tree */
- mem = malloc(size + 4);
+ mem = memalign(__alignof__(struct device_node), size + 4);
memset(mem, '\0', size);
+ /* Set up value for dm_test_livetree_align() */
+ *(u32 *)mem = BAD_OF_ROOT;
+
*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
debug(" unflattening %p...\n", mem);