Revert "Makefile: Drop SPL_FIT_GENERATOR / SPL_FIT_SOURCE support" changes

[J-u-boot.git] / doc / usage / fit / howto.rst

diff --git a/doc/usage/fit/howto.rst b/doc/usage/fit/howto.rst
index 675c9aa5bb0faf570d373936198a7a4943d84563..b5097d4460bf2ad11edae5463dd14de87e774bf6 100644 (file)
--- a/doc/usage/fit/howto.rst
+++ b/doc/usage/fit/howto.rst
@@ -57,6 +57,15 @@ own subnode under the /images node, which should then be referenced from one or
 multiple /configurations subnodes. The required images must be enumerated in
 the "loadables" property as a list of strings.
 
+If a platform specific image source file (.its) is shipped with the U-Boot
+source, it can be specified using the CONFIG_SPL_FIT_SOURCE Kconfig symbol.
+In this case it will be automatically used by U-Boot's Makefile to generate
+the image.
+If a static source file is not flexible enough, CONFIG_SPL_FIT_GENERATOR
+can point to a script which generates this image source file during
+the build process. It gets passed a list of device tree files (taken from the
+CONFIG_OF_LIST symbol).
+
 The SPL also records to a DT all additional images (called loadables) which are
 loaded. The information about loadables locations is passed via the DT node with
 fit-images name.