[U-Boot] [PATCH v5 1/2] env: register erase command

[Simon Goldschmidt]

On Wed, Jun 26, 2019 at 12:29 PM Frank Wunderlich
<frank-w at public-files.de> wrote:
>
> this patch adds basic changes for adding a erase-subcommand to env
>
> with this command the environment stored on non-volatile storage written
> by saveenv can be cleared.
>
> Signed-off-by: Frank Wunderlich <frank-w at public-files.de>
>
> squashed fixes
>  - start message with "Erasing"
>  - mark erase-function as optional
>  - env: separate eraseenv from saveenv
>
> Suggested-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>

Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>

> ---
>  cmd/Kconfig           |  8 ++++++++
>  cmd/nvedit.c          | 20 ++++++++++++++++++++
>  env/env.c             | 30 ++++++++++++++++++++++++++++++
>  include/environment.h | 17 +++++++++++++++++
>  4 files changed, 75 insertions(+)
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 0badcb3fe0..77e8a542d9 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -408,6 +408,14 @@ config CMD_SAVEENV
>           Save all environment variables into the compiled-in persistent
>           storage.
>
> +config CMD_ERASEENV
> +       bool "eraseenv"
> +       default n
> +       depends on CMD_SAVEENV
> +       help
> +         Erase environment variables from the compiled-in persistent
> +         storage.
> +
>  config CMD_ENV_EXISTS
>         bool "env exists"
>         default y
> diff --git a/cmd/nvedit.c b/cmd/nvedit.c
> index 52c242b4f6..63de758534 100644
> --- a/cmd/nvedit.c
> +++ b/cmd/nvedit.c
> @@ -761,6 +761,20 @@ U_BOOT_CMD(
>         "save environment variables to persistent storage",
>         ""
>  );
> +
> +#if defined(CONFIG_CMD_ERASEENV)
> +static int do_env_erase(cmd_tbl_t *cmdtp, int flag, int argc,
> +                       char * const argv[])
> +{
> +       return env_erase() ? 1 : 0;
> +}
> +
> +U_BOOT_CMD(
> +       eraseenv, 1, 0, do_env_erase,
> +       "erase environment variables from persistent storage",
> +       ""
> +);
> +#endif
>  #endif
>  #endif /* CONFIG_SPL_BUILD */
>
> @@ -1207,6 +1221,9 @@ static cmd_tbl_t cmd_env_sub[] = {
>  #endif
>  #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
>         U_BOOT_CMD_MKENT(save, 1, 0, do_env_save, "", ""),
> +#if defined(CONFIG_CMD_ERASEENV)
> +       U_BOOT_CMD_MKENT(erase, 1, 0, do_env_erase, "", ""),
> +#endif
>  #endif
>         U_BOOT_CMD_MKENT(set, CONFIG_SYS_MAXARGS, 0, do_env_set, "", ""),
>  #if defined(CONFIG_CMD_ENV_EXISTS)
> @@ -1282,6 +1299,9 @@ static char env_help_text[] =
>  #endif
>  #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
>         "env save - save environment\n"
> +#if defined(CONFIG_CMD_ERASEENV)
> +       "env erase - erase environment\n"
> +#endif
>  #endif
>  #if defined(CONFIG_CMD_NVEDIT_EFI)
>         "env set -e name [arg ...] - set UEFI variable; unset if 'arg' not specified\n"
> diff --git a/env/env.c b/env/env.c
> index 4b417b90a2..d3cbe2f915 100644
> --- a/env/env.c
> +++ b/env/env.c
> @@ -24,6 +24,8 @@ void env_fix_drivers(void)
>                         entry->load += gd->reloc_off;
>                 if (entry->save)
>                         entry->save += gd->reloc_off;
> +               if (entry->erase)
> +                       entry->erase += gd->reloc_off;
>                 if (entry->init)
>                         entry->init += gd->reloc_off;
>         }
> @@ -254,6 +256,34 @@ int env_save(void)
>         return -ENODEV;
>  }
>
> +int env_erase(void)
> +{
> +       struct env_driver *drv;
> +
> +       drv = env_driver_lookup(ENVOP_ERASE, gd->env_load_prio);
> +       if (drv) {
> +               int ret;
> +
> +               if (!drv->erase)
> +                       return -ENODEV;
> +
> +               if (!env_has_inited(drv->location))
> +                       return -ENODEV;
> +
> +               printf("Erasing Environment on %s... ", drv->name);
> +               ret = drv->erase();
> +               if (ret)
> +                       printf("Failed (%d)\n", ret);
> +               else
> +                       printf("OK\n");
> +
> +               if (!ret)
> +                       return 0;
> +       }
> +
> +       return -ENODEV;
> +}
> +
>  int env_init(void)
>  {
>         struct env_driver *drv;
> diff --git a/include/environment.h b/include/environment.h
> index cd96676141..de67cf4f0e 100644
> --- a/include/environment.h
> +++ b/include/environment.h
> @@ -200,6 +200,7 @@ enum env_operation {
>         ENVOP_INIT,     /* we want to call the init function */
>         ENVOP_LOAD,     /* we want to call the load function */
>         ENVOP_SAVE,     /* we want to call the save function */
> +       ENVOP_ERASE,    /* we want to call the erase function */
>  };
>
>  struct env_driver {
> @@ -225,6 +226,15 @@ struct env_driver {
>          */
>         int (*save)(void);
>
> +       /**
> +        * erase() - Erase the environment on storage
> +        *
> +        * This method is optional and required for 'eraseenv' to work.
> +        *
> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*erase)(void);
> +
>         /**
>          * init() - Set up the initial pre-relocation environment
>          *
> @@ -303,6 +313,13 @@ int env_load(void);
>   */
>  int env_save(void);
>
> +/**
> + * env_erase() - Erase the environment on storage
> + *
> + * @return 0 if OK, -ve on error
> + */
> +int env_erase(void);
> +
>  /**
>   * env_fix_drivers() - Updates envdriver as per relocation
>   */
> --
> 2.17.1
>