[PATCH 6/7] Kconfig: Document the limitations of the simple SPL_LOAD_FIT path

[Alexandru Gagniuc <mr.nuke.me@gmail.com>]

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 _know_ issues, and is not intended
to be a complete list of all follies.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
---
 common/Kconfig.boot | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/common/Kconfig.boot b/common/Kconfig.boot
index 9c335f4f8c..f77e59a22a 100644
--- 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"
+	     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
-- 
2.26.2