lib: time: Add microsecond timer

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

diff --git a/doc/README.splashprepare b/doc/README.splashprepare
index 61b4ec53ecaddee676e0c6c2ec1dac65efe544d4..3cb5b5aeb484c18b9f7c6f0173fab4c7e2fb9ec1 100644 (file)
--- a/doc/README.splashprepare
+++ b/doc/README.splashprepare
@@ -5,4 +5,30 @@ 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. The FIT image has to start at the 'offset' field address in the
+selected splash location. The name of splash image within the FIT shall be
+specified by the environment variable "splashfile".
+
+In case the environment variable "splashfile" is not defined the default name
+'splash.bmp' will be used.