Kconfig: Document the limitations of the simple SPL_LOAD_FIT path

The "simple" SPL_LOAD_FIT path is the most compliant with the format
documented in doc/uImage.FIT/source_file_format.txt. The other two
paths to load a FIT are SPL_LOAD_FIT_FULL and the "bootm" command.

Since the Kconfig menu is the most likely place for a new user to see
these options, it seems like the most logical candidate to document
the limitations. This documents the _known_ issues, and is not
intended to be a complete list of all follies.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/common/Kconfig.boot b/common/Kconfig.boot
index 9c335f4..5a18d62 100644 (file)
--- a/common/Kconfig.boot
+++ b/common/Kconfig.boot
@@ -202,6 +202,16 @@ config SPL_LOAD_FIT
          particular it can handle selecting from multiple device tree
          and passing the correct one to U-Boot.
 
+         This path has the following limitations:
+
+         1. "loadables" images, other than FTDs, which do not have a "load"
+            property will not be loaded. This limitation also applies to FPGA
+            images with the correct "compatible" string.
+         2. For FPGA images, only the "compatible" = "u-boot,fpga-legacy"
+            loading method is supported.
+         3. FDTs are only loaded for images with an "os" property of "u-boot".
+            "linux" images are also supported with Falcon boot mode.
+
 config SPL_LOAD_FIT_ADDRESS
        hex "load address of fit image"
        depends on SPL_LOAD_FIT