summaryrefslogtreecommitdiffstats
path: root/doc/uImage.FIT/source_file_format.txt
diff options
context:
space:
mode:
Diffstat (limited to 'doc/uImage.FIT/source_file_format.txt')
-rw-r--r--doc/uImage.FIT/source_file_format.txt20
1 files changed, 19 insertions, 1 deletions
diff --git a/doc/uImage.FIT/source_file_format.txt b/doc/uImage.FIT/source_file_format.txt
index 3175c9f0b7..3db068d6c8 100644
--- a/doc/uImage.FIT/source_file_format.txt
+++ b/doc/uImage.FIT/source_file_format.txt
@@ -2,6 +2,7 @@ U-Boot new uImage source file format (bindings definition)
==========================================================
Author: Marian Balakowicz <m8@semihalf.com>
+External data additions, 25/1/16 Simon Glass <sjg@chromium.org>
1) Introduction
---------------
@@ -262,7 +263,24 @@ Older, 2.4 kernel and 2.6 non-FDT kernel do not use FDT blob, in such cases
not* be specified in a configuration node.
-8) Examples
+8) External data
+----------------
+
+The above format shows a 'data' property which holds the data for each image.
+It is also possible for this data to reside outside the FIT itself. This
+allows the FIT to be quite small, so that it can be loaded and scanned
+without loading a large amount of data. Then when an image is needed it can
+be loaded from an external source.
+
+In this case the 'data' property is omitted. Instead you can use:
+
+ - data-offset : offset of the data in a separate image store. The image
+ store is placed immediately after the last byte of the device tree binary,
+ aligned to a 4-byte boundary.
+ - data-size : size of the data in bytes
+
+
+9) Examples
-----------
Please see doc/uImage.FIT/*.its for actual image source files.
OpenPOWER on IntegriCloud