ENGR00174841 [U-Boot]Add a command to erase any pre-saved environment

A "destroyenv" command is provided to erase any pre-save environment in the
boot storage. The command simply add 1 to the CRC section and write it back
to the storage. Per the logic of U-Boot, this means after a reset, the
software will recognize the stored environment settings as "damaged" and turn
to use the default one, which is defined in "default_environment"

With this command, platform bring up owner can maintain a "ready-to-use"
environment settings in software which others can use very conviniently.
U-boot users can also use it to do a environment restore if they want.

-----------------------------------
Usage Example:
> destroyenv

invalidate the CRC
write invalidate enviroment data to storage
Erasing SPI flash...Erasing SPI NOR flash 0xc0000 [0x2000 bytes]
..SUCCESS

Writing to SPI flash...Writing SPI NOR flash
0xc0000 [0x2000 bytes] <- ram 0x276009b8
SUCCESS

done
>
-----------------------------------

Signed-off-by: Eric Sun <jian.sun@freescale.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/environment.h b/include/environment.h
index e0759ae..1ab9312 100644
--- a/include/environment.h
+++ b/include/environment.h
@@ -2,6 +2,8 @@
  * (C) Copyright 2002
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
@@ -147,6 +149,8 @@ unsigned char env_get_char_memory (int index);
 
 /* Function that updates CRC of the enironment */
 void env_crc_update (void);
+/* Function that destroys CRC of the environment */
+void env_crc_destroy(void);
 
 /* [re]set to the default environment */
 void set_default_env(void);