[U-Boot] [PATCH v4 6/7] env: make "env default" selective, check and apply

[Gerlando Falauto]

On 08/24/2012 04:56 PM, Marek Vasut wrote:
> Dear Gerlando Falauto,
>
>> Change the syntax (user API) for "env default":
>>    -f: override write-once variables
>>    var... : accept individual variable(s)
>>    -a: all (resetting the whole env is NOT the default behavior)
>>
>> Enable variable checking and make changes effective by
>> enabling do_apply argument to himport_r().
>>
>> Signed-off-by: Gerlando Falauto<gerlando.falauto at keymile.com>
>> ---
>>   common/cmd_nvedit.c   |   40 ++++++++++++++++++++++++++++++++++------
>>   common/env_common.c   |   28 +++++++++++++++++++++++++++-
>>   include/environment.h |    3 +++
>>   3 files changed, 64 insertions(+), 7 deletions(-)
>>
>> diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c
>> index b0860f3..ac2b985 100644
>> --- a/common/cmd_nvedit.c
>> +++ b/common/cmd_nvedit.c
>> @@ -656,14 +656,41 @@ int envmatch(uchar *s1, int i2)
>>   	return -1;
>>   }
>>
>> -static int do_env_default(cmd_tbl_t *cmdtp, int flag,
>> +static int do_env_default(cmd_tbl_t *cmdtp, int __flag,
>>   			  int argc, char * const argv[])
>>   {
>> -	if (argc != 2 || strcmp(argv[1], "-f") != 0)
>> -		return CMD_RET_USAGE;
>> +	int all = 0, flag = 0;
>>
>> -	set_default_env("## Resetting to default environment\n");
>> -	return 0;
>> +	debug("Initial value for argc=%d\n", argc);
>> +	while (--argc>  0&&  **++argv == '-') {
>
> mmmmm ... **++argv, yummy :) This might use some cleanup, to make more readable.

Uhm, this pattern is being used all over the place on that file (that's 
where I copied it from).

> Don't we have some getopt or something too ?

Not that I (or "git grep") know of.

>
>> +		char *arg = *argv;
>> +
>> +		while (*++arg) {
>> +			switch (*arg) {
>> +			case 'a':		/* default all */
>> +				all = 1;
>> +				break;
>> +			case 'f':		/* force */
>> +				flag |= H_FORCE;
>> +				break;
>> +			default:
>> +				return cmd_usage(cmdtp);
>> +			}
>> +		}
>> +	}
>> +	debug("Final value for argc=%d\n", argc);
>> +	if (all&&  (argc == 0)) {
>> +		/* Reset the whole environment */
>> +		set_default_env("## Resetting to default environment\n");
>> +		return 0;
>> +	}
>> +	if (!all&&  (argc>  0)) {
>> +		/* Reset individual variables */
>> +		set_default_vars(argc, argv);
>> +		return 0;
>> +	}
>> +
>> +	return cmd_usage(cmdtp);
>>   }
>>
>>   static int do_env_delete(cmd_tbl_t *cmdtp, int flag,
>> @@ -994,7 +1021,8 @@ U_BOOT_CMD(
>>   #if defined(CONFIG_CMD_ASKENV)
>>   	"ask name [message] [size] - ask for environment variable\nenv "
>>   #endif
>> -	"default -f - reset default environment\n"
>> +	"default [-f] -a - [forcibly] reset default environment\n"
>> +	"env default [-f] var [...] - [forcibly] reset variable(s) to their
>> default values\n" #if defined(CONFIG_CMD_EDITENV)
>>   	"env edit name - edit environment variable\n"
>>   #endif
>> diff --git a/common/env_common.c b/common/env_common.c
>> index c6e7c4c..482d715 100644
>> --- a/common/env_common.c
>> +++ b/common/env_common.c
>> @@ -177,6 +177,11 @@ const uchar *env_get_addr(int index)
>>
>>   void set_default_env(const char *s)
>>   {
>> +	/*
>> +	 * By default, do not apply changes as they will eventually
>> +	 * be applied by someone else
>> +	 */
>> +	int do_apply = 0;
>>   	if (sizeof(default_environment)>  ENV_SIZE) {
>>   		puts("*** Error - default environment is too large\n\n");
>>   		return;
>> @@ -188,6 +193,14 @@ void set_default_env(const char *s)
>>   				"using default environment\n\n",
>>   				s + 1);
>>   		} else {
>> +			/*
>> +			 * This set_to_default was explicitly asked for
>> +			 * by the user, as opposed to being a recovery
>> +			 * mechanism.  Therefore we check every single
>> +			 * variable and apply changes to the system
>> +			 * right away (e.g. baudrate, console).
>> +			 */
>> +			do_apply = 1;
>>   			puts(s);
>>   		}
>>   	} else {
>> @@ -196,12 +209,25 @@ void set_default_env(const char *s)
>>
>>   	if (himport_r(&env_htab, (char *)default_environment,
>>   			sizeof(default_environment), '\0', 0,
>> -			0, NULL, 0 /* do_apply */) == 0)
>> +			0, NULL, do_apply) == 0)
>>   		error("Environment import failed: errno = %d\n", errno);
>>
>>   	gd->flags |= GD_FLG_ENV_READY;
>>   }
>>
>> +
>> +/* [re]set individual variables to their value in the default environment
>> */ +int set_default_vars(int nvars, char * const vars[])
>> +{
>> +	/*
>> +	 * Special use-case: import from default environment
>> +	 * (and use \0 as a separator)
>> +	 */
>> +	return himport_r(&env_htab, (const char *)default_environment,
>> +				sizeof(default_environment), '\0', H_NOCLEAR,
>> +				nvars, vars, 1 /* do_apply */);
>> +}
>> +
>>   /*
>>    * Check if CRC is valid and (if yes) import the environment.
>>    * Note that "buf" may or may not be aligned.
>> diff --git a/include/environment.h b/include/environment.h
>> index 90fb130..e8ab703 100644
>> --- a/include/environment.h
>> +++ b/include/environment.h
>> @@ -181,6 +181,9 @@ void env_crc_update(void);
>>   /* [re]set to the default environment */
>>   void set_default_env(const char *s);
>>
>> +/* [re]set individual variables to their value in the default environment
>> */ +int set_default_vars(int nvars, char * const vars[]);
>> +
>>   /* Import from binary representation into hash table */
>>   int env_import(const char *buf, int check);
>
> Best regards,
> Marek Vasut

Best regards,
Gerlando