env: register erase command

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

1 files changed, 30 insertions, 0 deletions

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;