Re: [PATCH] environment: add new global.env.noload parameter

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, Nov 28, 2025 at 06:21:14PM +0100, Ahmad Fatoum wrote:
> It can be useful for board code to deny loading an environment without
> disabling it altogether, e.g. to disable load of the environment when
> entering a recovery mode. Add a global variable that allows for just
> that.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  common/environment.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/common/environment.c b/common/environment.c
> index d7f5f51cfc6d..d49f255ef007 100644
> --- a/common/environment.c
> +++ b/common/environment.c
> @@ -54,6 +54,7 @@ struct action_data {
>  #define TMPDIR "/.defaultenv"
>  
>  static int global_env_autoprobe = IS_ENABLED(CONFIG_INSECURE);
> +static int global_env_noload = false;
>  static char *default_environment_path;
>  
>  void default_environment_path_set(const char *path)
> @@ -455,7 +456,7 @@ int envfs_load(const char *filename, const char *dir, unsigned flags)
>  	size_t size, rsize;
>  
>  #ifdef __BAREBOX__
> -	if (!IS_ALLOWED(SCONFIG_ENVIRONMENT_LOAD))
> +	if (!IS_ALLOWED(SCONFIG_ENVIRONMENT_LOAD) || global_env_noload)
>  		return -EPERM;

With this you forbid to ever load an environment. The commit message
suggests you are looking for a way to skip loading of the environment,
so I would rather expect the check in the caller in common/startup.c

>  #ifdef __BAREBOX__
> +
>  static int register_env_vars(void)
>  {
>  	globalvar_add_simple_bool("env.autoprobe", &global_env_autoprobe);
> +	globalvar_add_simple_bool("env.noload", &global_env_noload);

globalvars are usually meant for variables that are set/read from the
shell. What's your usecase for setting this from shell?

Having this as globalvar implies there is a corresponding nvvar. If I
read the code correctly then setting nv.env.noload=true in the builtin
default environment will not have the effect that loading of the
persistent environment is suppressed. Setting nv.env.noload=true in the
persistent environment obviously also isn't meaningful. The only effect
will be that a loadenv command no longer works.

Making this a globalvar seems rather confusing to me.

Sascha

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