[PATCH 2/2] bootm: Do not cross 1MiB sections for the devicetree

[Sascha Hauer]

ARM Linux only maps a single 1MiB section for the devicetree. This has
a 1Mib alignment, so we are not allowed to cross such a boundary. Align
the devicetree to the next power of two so that this never happens.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 commands/bootm.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/commands/bootm.c b/commands/bootm.c
index d14ec2b..98d2e4f 100644
--- a/commands/bootm.c
+++ b/commands/bootm.c
@@ -141,6 +141,7 @@ static int bootm_open_oftree(struct image_data *data, const char *oftree, int nu
 	struct fdt_header *fdt, *fixfdt;
 	int ret;
 	size_t size;
+	unsigned int align;
 
 	if (bootm_verbose(data))
 		printf("Loading oftree from '%s'\n", oftree);
@@ -189,7 +190,14 @@ static int bootm_open_oftree(struct image_data *data, const char *oftree, int nu
 				file_type_to_string(ft));
 	}
 
-	fixfdt = xmemalign(4096, size + OFTREE_SIZE_INCREASE);
+	/*
+	 * ARM Linux uses a single 1MiB section (with 1MiB alignment)
+	 * for mapping the devicetree, so we are not allowed to cross
+	 * 1MiB boundaries.
+	 */
+	align = 1 << fls(size + OFTREE_SIZE_INCREASE - 1);
+
+	fixfdt = xmemalign(align, size + OFTREE_SIZE_INCREASE);
 	memcpy(fixfdt, fdt, size);
 
 
-- 
1.7.10.4