[U-Boot] fw_setenv usage for multiple copies of U-Boot Environment Variables

[U-Boot] fw_setenv usage for multiple copies of U-Boot Environment Variables

[Amarendra Reddy]

Hi all

Consider we have multiple copies of U-Boot Environment Variables.
Each copy protected by CRC value.

Can we use fw_printenv and fw_setenv utilities from Linux Application ?

Please guide me regarding this.

Thanks
Amarendra Reddy


Larsen & Toubro Limited

www.larsentoubro.com

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[U-Boot] fw_setenv usage for multiple copies of U-Boot Environment Variables

[Wolfgang Denk]

Dear Amarendra Reddy,

In message <FACCDA52663F0249A0002E4E413B0AA7E62D7F@POCITMSEXMB01.LntUniverse.com> you wrote:
>
> Consider we have multiple copies of U-Boot Environment Variables.
> Each copy protected by CRC value.

Your question is not quite clear.  I assume you are talking about what
we call "redundant environment".

> Can we use fw_printenv and fw_setenv utilities from Linux Application ?

Yes, fw_printenv and fw_setenv can handle redundant environment
setups.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
In the beginning there was nothing.
And the Lord said "Let There Be Light!"
And still there was nothing, but at least now you could see it.

[U-Boot] fw_setenv usage for multiple copies of U-Boot Environment Variables

[Amarendra Reddy]

Hi Wolfgang Denk,

Thank you for the reply. Yes I am talking about "redundant environment".

If we have four "redundant environment" copies in the same partition(mtd1)... Does the below fw_env.config configuration hold good ?

####################################################
# File: fw_env.config
# Configuration file for fw_(printenv/saveenv) utility.
# Up to two entries are valid, in this case the redundand
# environment sector is assumed present.

# MTD device name       Device offset   Env. size       Flash sector size
/dev/mtd1               0x00000         0x02000         0x20000
/dev/mtd1               0x20000         0x02000         0x20000
/dev/mtd1               0x40000         0x02000         0x20000
/dev/mtd1               0x60000         0x02000         0x20000
####################################################


Thanks & Regards
Amarendra Reddy

-----Original Message-----
From: Wolfgang Denk [mailto:wd at denx.de]
Sent: Thursday, April 28, 2011 3:58 PM
To: Amarendra Reddy
Cc: u-boot at lists.denx.de
Subject: Re: [U-Boot] fw_setenv usage for multiple copies of U-Boot Environment Variables

Dear Amarendra Reddy,

In message <FACCDA52663F0249A0002E4E413B0AA7E62D7F@POCITMSEXMB01.LntUniverse.com> you wrote:
>
> Consider we have multiple copies of U-Boot Environment Variables.
> Each copy protected by CRC value.

Your question is not quite clear.  I assume you are talking about what we call "redundant environment".

> Can we use fw_printenv and fw_setenv utilities from Linux Application ?

Yes, fw_printenv and fw_setenv can handle redundant environment setups.

Best regards,

Wolfgang Denk

--
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de In the beginning there was nothing.
And the Lord said "Let There Be Light!"
And still there was nothing, but at least now you could see it.


Larsen & Toubro Limited

www.larsentoubro.com

This Email may contain confidential or privileged information for the intended recipient (s) If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.

[U-Boot] fw_setenv usage for multiple copies of U-Boot Environment Variables

[Detlev Zundel]

Hi Amarendra,

> Hi Wolfgang Denk,
>
> Thank you for the reply. Yes I am talking about "redundant environment".
>
> If we have four "redundant environment" copies in the same
> partition(mtd1)... Does the below fw_env.config configuration hold
> good ?

U-Boot cannot cope with more than two redundant copies.

> ####################################################
> # File: fw_env.config
> # Configuration file for fw_(printenv/saveenv) utility.
> # Up to two entries are valid, in this case the redundand
> # environment sector is assumed present.

Read the text carefully: "Up to two entries are valid"....

>
> # MTD device name       Device offset   Env. size       Flash sector size
> /dev/mtd1               0x00000         0x02000         0x20000
> /dev/mtd1               0x20000         0x02000         0x20000
> /dev/mtd1               0x40000         0x02000         0x20000
> /dev/mtd1               0x60000         0x02000         0x20000
> ####################################################

On the other hand why exactly do you need four redundant environments?
The idea behind redundant environments is that a powercut _while_
updating one copy can be handled by having a backup copy.  It is _not_
meant to handle faulting devices in any way.

Cheers
  Detlev

-- 
I have always observed that the pretensions of all people are in
exact inverse ratio to their merits; this is one of the axioms of
morals.                            -- Joseph Lagrange
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de