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

Marek Vasut
2012-08-24T14:56:44Z

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@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.
Don't we have some getopt or something too ?

> + 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