[U-Boot] Getting started with uboot

Elie De Brauwer eliedebrauwer at gmail.com
Wed Aug 4 21:26:04 CEST 2010


On 08/04/10 20:47, Thomas Heller wrote:
> Where does uboot store the environment variables?
>
> I have my tx25 board booting correctly from uboot when
> entering interactive commands:
>
> But when I call 'saveenv' then it doesn't boot any longer;
> it seems that 'saveenv' overwrites parts of the root file system.
>
> So, my question is: where does uboot save the environment?
>

If you take a look in include/configs/xt25.h (which should be the
definition of your board) this contains (e.g. on a 2010.06)

...
#define	CONFIG_SYS_MONITOR_LEN		(256 << 10)	/* 256 kB for U-Boot */
...
/* No NOR flash present */
#define CONFIG_SYS_NO_FLASH	1
#define	CONFIG_ENV_IS_IN_NAND
#define	CONFIG_ENV_OFFSET	CONFIG_SYS_MONITOR_LEN
#define CONFIG_ENV_SIZE		(128 * 1024)	/* 128 kB NAND block size */
#define CONFIG_ENV_OFFSET_REDUND	(CONFIG_ENV_OFFSET + CONFIG_ENV_SIZE)

It will look for the environment at offset 256k and for a redundant one 
at 256k+128k.

hth
E.
-- 
Elie De Brauwer



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