pico-imx7d: README: Drop old instructions about secure mode

[oweals/u-boot.git] / doc / README.splashprepare

diff --git a/doc/README.splashprepare b/doc/README.splashprepare
index 61b4ec53ecaddee676e0c6c2ec1dac65efe544d4..f1418de18b017ee8b67484927636afdef3e83107 100644 (file)
--- a/doc/README.splashprepare
+++ b/doc/README.splashprepare
@@ -5,4 +5,27 @@ The splash_screen_prepare() function is a weak function defined in
 common/splash.c. It is called as part of the splash screen display
 sequence. It gives the board an opportunity to prepare the splash
 image data before it is processed and sent to the frame buffer by
-U-Boot.  Define your own version to use this feature.
+U-Boot. Define your own version to use this feature.
+
+CONFIG_SPLASH_SOURCE
+
+Use the splash_source.c library. This library provides facilities to declare
+board specific splash image locations, routines for loading splash image from
+supported locations, and a way of controlling the selected splash location
+using the "splashsource" environment variable.
+
+splashsource works as follows:
+- If splashsource is set to a supported location name as defined by board code,
+  use that splash location.
+- If splashsource is undefined, use the first splash location as default.
+- If splashsource is set to an unsupported value, do not load a splash screen.
+
+A splash source location can describe either storage with raw data, a storage
+formatted with a file system or a FIT image. In case of a filesystem, the splash
+screen data is loaded as a file. The name of the splash screen file can be
+controlled with the environment variable "splashfile".
+
+To enable loading the splash image from a FIT image, CONFIG_FIT must be
+enabled. Struct splash_location field 'name' should match the splash image
+name within the FIT and the FIT should start at the 'offset' field address in
+the specified storage.