[PATCH] env: Add option to only ever append environment

[Marek Vasut]

On 6/2/20 8:42 AM, Rasmus Villemoes wrote:
> On 29/05/2020 19.54, Marek Vasut wrote:
>> +config ENV_APPEND
>> +	bool "Always append the environment with new data"
>> +	default n
>> +	help
>> +	  If defined, the environment hash table is only ever appended with new
>> +	  data, but the existing hash table can never be dropped and reloaded
>> +	  with newly imported data. This may be used in combination with static
>> +	  flags to e.g. to protect variables which must not be modified.
>> +
>>  config ENV_ACCESS_IGNORE_FORCE
>>  	bool "Block forced environment operations"
>>  	default n
>> diff --git a/env/env.c b/env/env.c
>> index 024d36fdbe..967a9d36d7 100644
>> --- a/env/env.c
>> +++ b/env/env.c
>> @@ -204,7 +204,9 @@ int env_load(void)
>>  		ret = drv->load();
>>  		if (!ret) {
>>  			printf("OK\n");
>> +#if !CONFIG_IS_ENABLED(ENV_APPEND)
>>  			return 0;
>> +#endif
> 
> Don't use CONFIG_IS_ENABLED() unless you actually introduce both
> CONFIG_FOO and CONFIG_SPL_FOO. Otherwise the above
> CONFIG_IS_ENABLED(ENV_APPEND) is guaranteed to evaluate to false in SPL.
> Of course that only matters if environment support is enabled in SPL,
> but some actually use that.

We actually want to use CONFIG_IS_ENABLED() as much as possible to make
these options future-proof, so that others won't have to chase down all
kinds of #ifdef CONFIG stuff and fix it later on for SPL/TPL/etc.