All of lore.kernel.org
 help / color / mirror / Atom feed
From: Steven Scholz <steven.scholz@imc-berlin.de>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] Verify CRC on environment?
Date: Wed, 25 May 2005 11:14:18 +0200	[thread overview]
Message-ID: <429441EA.60203@imc-berlin.de> (raw)
In-Reply-To: <20050525091247.D1165C1512@atlas.denx.de>

Wolfgang Denk wrote:

> In message <42943EDA.7020404@imc-berlin.de> you wrote:
> 
>>(how) can I verify the CRC of the environment using the crc32 command?
> 
> 
> => help crc
> 
> 
>>I am using CFG_ENV_ADDR_REDUND, so I guess I have to skip 5 bytes of header.
> 
> 
> Right.
> 
> 
>>Do the two last 0x00 count?
> 
> 
> Yes. As does all the rest of the configured CFG_ENV_SIZE
> 
> 
>>My environment is at 10030000:
>>
>>10030000: 4c 16 71 5f 00 62 6f 6f 74 64 65 6c 61 79 3d 30
>>10030010: 00 62 61 75 64 72 61 74 65 3d 31 31 35 32 30 30
>>10030020: 00 73 65 72 69 61 6c 23 3d 31 32 38 33 30 30 00
>>10030030: 73 74 64 69 6e 3d 73 65 72 69 61 6c 00 73 74 64
>>10030040: 6f 75 74 3d 73 65 72 69 61 6c 00 73 74 64 65 72
>>10030050: 72 3d 73 65 72 69 61 6c 00 00 3d 73 65 72 69 61
>>10030060: 6c 00 00 64 65 72 72 3d 73 65 72 69 61 6c 00 00
>>10030070: 74 64 65 72 72 3d 73 65 72 69 61 6c 00 00
>>
>>That 0x7D, so 125+1 = 126 bytes
>>
>>So I thought I have to calculate the crc over 126 - 5 = 0x79 bytes
>>
>>crc32 10030005 0x79
>>CRC32 for 10030005 ... 1003007d ==> 8889f3af
>>
>>But this is obviously wrong... :-(
> 
> 
> Yes, this is wrong. You must use "CFG_ENV_SIZE - 5" as length for the
> crc command.

Hmm. But after the two last 0x00 there's "garbage" in the flash, i.e. old, 
overwritten and erased values.
So the count as well?

--
Steven

  reply	other threads:[~2005-05-25  9:14 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-05-25  9:01 [U-Boot-Users] Verify CRC on environment? Steven Scholz
2005-05-25  9:12 ` Wolfgang Denk
2005-05-25  9:14   ` Steven Scholz [this message]
2005-05-25  9:32     ` Wolfgang Denk

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=429441EA.60203@imc-berlin.de \
    --to=steven.scholz@imc-berlin.de \
    --cc=u-boot@lists.denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.