[U-Boot] [PATCH v2 1/2] env: register erase command

[Frank Wunderlich]

Signed-off-by: Frank Wunderlich <frank-w at public-files.de>
---
 cmd/nvedit.c          | 13 +++++++++++++
 env/env.c             | 30 ++++++++++++++++++++++++++++++
 env/mmc.c             |  7 +++++++
 include/environment.h | 17 +++++++++++++++++
 4 files changed, 67 insertions(+)

diff --git a/cmd/nvedit.c b/cmd/nvedit.c
index 24a6cf7824..3b5c62d629 100644
--- a/cmd/nvedit.c
+++ b/cmd/nvedit.c
@@ -756,11 +756,22 @@ static int do_env_save(cmd_tbl_t *cmdtp, int flag, int argc,
 	return env_save() ? 1 : 0;
 }

+static int do_env_erase(cmd_tbl_t *cmdtp, int flag, int argc,
+			char * const argv[])
+{
+	return env_erase() ? 1 : 0;
+}
+
 U_BOOT_CMD(
 	saveenv, 1, 0,	do_env_save,
 	"save environment variables to persistent storage",
 	""
 );
+U_BOOT_CMD(
+	eraseenv, 1, 0,	do_env_erase,
+	"erase environment variables from persistent storage",
+	""
+);
 #endif
 #endif /* CONFIG_SPL_BUILD */

@@ -1207,6 +1218,7 @@ 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, "", ""),
+	U_BOOT_CMD_MKENT(erase, 1, 0, do_env_erase, "", ""),
 #endif
 	U_BOOT_CMD_MKENT(set, CONFIG_SYS_MAXARGS, 0, do_env_set, "", ""),
 #if defined(CONFIG_CMD_ENV_EXISTS)
@@ -1282,6 +1294,7 @@ static char env_help_text[] =
 #endif
 #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
 	"env save - save environment\n"
+	"env erase - erase environment\n"
 #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..25441370e6 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("Erase 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/env/mmc.c b/env/mmc.c
index c3cf35d01b..c5b6356363 100644
--- a/env/mmc.c
+++ b/env/mmc.c
@@ -242,6 +242,12 @@ fini:
 	fini_mmc_for_env(mmc);
 	return ret;
 }
+
+static int env_mmc_erase(void)
+{
+	return 0;//1 on error
+}
+
 #endif /* CONFIG_CMD_SAVEENV && !CONFIG_SPL_BUILD */

 static inline int read_env(struct mmc *mmc, unsigned long size,
@@ -351,5 +357,6 @@ U_BOOT_ENV_LOCATION(mmc) = {
 	.load		= env_mmc_load,
 #ifndef CONFIG_SPL_BUILD
 	.save		= env_save_ptr(env_mmc_save),
+	.erase		= env_mmc_erase,
 #endif
 };
diff --git a/include/environment.h b/include/environment.h
index cd96676141..5024cbea7e 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 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