fdt: Add option to default to most compatible conf in a fit image
When booting a fit image with multiple configurations, the user either has to
specify which configuration to use explicitly, or there has to be a default
defined which is chosen automatically. This change adds an option to change
that behavior so that a configuration can be selected explicitly, or the
configuration which has the device tree that claims to be compatible with the
earliest item in U-Boot's device tree.
In other words, if U-Boot claimed to be compatible with A, B, and then C, and
the configurations claimed to be compatible with A, D and B, D and D, E, the
first configuration, A, D, would be chosen. Both the first and second
configurations match, but the first one matches a more specific entry in
U-Boot's device tree. The order in the kernel's device tree is ignored.
Signed-off-by: Gabe Black <gabeblack@google.com>
Commit-Ready: Gabe Black <gabeblack@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/README b/README
index afdf591..6c77842 100644
--- a/README
+++ b/README
@@ -2597,6 +2597,17 @@
-150 common/cmd_nand.c Incorrect FIT image format
151 common/cmd_nand.c FIT image format OK
+- FIT image support:
+ CONFIG_FIT
+ Enable support for the FIT uImage format.
+
+ CONFIG_FIT_BEST_MATCH
+ When no configuration is explicitly selected, default to the
+ one whose fdt's compatibility field best matches that of
+ U-Boot itself. A match is considered "best" if it matches the
+ most specific compatibility entry of U-Boot's fdt's root node.
+ The order of entries in the configuration's fdt is ignored.
+
- Standalone program support:
CONFIG_STANDALONE_LOAD_ADDR