Re: [RFC PATCH] Provide mechanism for build-time default env entries

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.

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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 custom
  

•  environment entries to be added to the default environment. Care must
  

•  be taken to not break the environment, incompatible entries may cause
  

•  failure to compile, or failure of the target board to properly
  

•  initialize or boot. The format is key=value pairs, with entries
  

•  separated 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