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

Marek Vasut
2012-08-24T21:10:05Z

Dear 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@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).

That doesn't mean it's right, it just means the codebase is in a very sad state
:-C

> > Don't we have some getopt or something too ?
>
> Not that I (or "git grep") know of.

Even more :-C

> >> + 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