[U-Boot] fw_setenv device not accessible

[Wolfgang Denk]

Dear pshambhu,

In message <1383039837672-166275.post at n7.nabble.com> you wrote:
>  
>     I am unable to change the u-boot environment variables from the Linux
> environment using fw_setenv and fw_printenv. 
> I am able to list out the variables from the particular partition, but i am
> unable to change the variable value using fw_setenv.
> 
> [Linux promp]# fw_setenv Status 0
> Can't open /dev/mtd4: Permission denied
> Error: can't write fw_env to flash
> 
> i tried to change the permission of /dev/mtd4 as well, but i am getting the
> same problem.

Obviously partition mtd4 is mapped as read-only.  You need read-write
mode instead.  This has nothing to do with the permissions on the
/dev/mtd4 special file, but with the mapping of the MTD device in the
device tree or the mtdargs boot argument or however you pass that
information to Linux on your system.

Best regards,

Wolfgang Denk

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