On 2020-01-20 09:51, Wolfgang Denk wrote:
Dear Joel,
In message 20200119073738.29189-1-mrjoel@lixil.net you wrote:
This enables the building user to specify environment values to be included in the static default_environment with an image. This is useful to build multiple otherwise like configured images, varying by environment unique entries.
I expected something like this to already be present, but couldn't find such a mechanism. I also assumed that something similar may have been proposed previously, but also couldn't find anything via searching.
...
+config USER_ENV_SETTINGS
- string "User build-time additional environment entries"
- help
This value is reserved for the building user to provide customenvironment entries to be added to the default environment. Caremust
be taken to not break the environment, incompatible entries maycause
failure to compile, or failure of the target board to properlyinitialize or boot. The format is key=value pairs, with entriesseparated by C-style escaped null terminated values, such as:"key1=valueA\0key2=valueB\0key3=valueC".Something in your descripotion must be missing, or this change makes no sense to me.
#ifdef CONFIG_EXTRA_ENV_SETTINGS CONFIG_EXTRA_ENV_SETTINGS +#endif +#ifdef CONFIG_USER_ENV_SETTINGS
- CONFIG_USER_ENV_SETTINGS
#endif
What exactly is the difference between CONFIG_EXTRA_ENV_SETTINGS and CONFIG_USER_ENV_SETTINGS for you, i. e. what can you do with CONFIG_USER_ENV_SETTINGS that cannot be done in exatly the same way with CONFIG_EXTRA_ENV_SETTINGS?
Maybe it would help if you include any code that is actually using this feature?
Best regards,
Wolfgang Denk
The main different to me is that many boards set/replace CONFIG_EXTRA_ENV_SETTINGS, making it unusable as a user build-time configuration value. As a result, I can actually specify values for CONFIG_USER_ENV_SETTINGS and have them included in the resulting environment instead of overridden by the board configuration.
There is intentionally no code using this feature, as meant in the description it is intended to be reserved for the building user's usage. The specific use case for which I'm using it is to ease building of multiple otherwise identical images, embedding a fixed and well known set of ethernet MAC addresses into each unique image for execution in environments with no environment storage. It is meant to be used for any other values changed or added in the default image environment though - if there is a better way to accomplish this I'd be all for it, but I couldn't find anything, thus the RFC patch.
Joel