Add mention of this option since it does a similar thing to the text environment.
Signed-off-by: Simon Glass sjg@chromium.org Suggested-by: Rasmus Villemoes rasmus.villemoes@prevas.dk Reviewed-by: Marek Behún marek.behun@nic.cz ---
Changes in v9: - Fix blank line between tags - Fix typo in commit message
Changes in v8: - Fix ambiguity about what is ignored
Changes in v7: - Add new patch to explain the relationship with DEFAULT_ENV_FILE
doc/usage/environment.rst | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst index 667fd193ea1..adf2e067b58 100644 --- a/doc/usage/environment.rst +++ b/doc/usage/environment.rst @@ -454,3 +454,18 @@ The signature of the callback functions is:: include/search.h
The return value is 0 if the variable change is accepted and 1 otherwise. + + +External environment file +------------------------- + +The `CONFIG_USE_DEFAULT_ENV_FILE` option provides a way to bypass the +environment generation in U-Boot. If enabled, then `CONFIG_DEFAULT_ENV_FILE` +provides the name of a file which is converted into the environment, +completely bypassing the standard environment variables in `env_default.h`. + +The format is the same as accepted by the mkenvimage tool, with lines containing +key=value pairs. Blank lines and lines beginning with # are ignored. + +Future work may unify this feature with the text-based environment, perhaps +moving the contents of `env_default.h` to a text file.