* [U-Boot-Users] Verify CRC on environment?
@ 2005-05-25 9:01 Steven Scholz
2005-05-25 9:12 ` Wolfgang Denk
0 siblings, 1 reply; 4+ messages in thread
From: Steven Scholz @ 2005-05-25 9:01 UTC (permalink / raw)
To: u-boot
Hi,
(how) can I verify the CRC of the environment using the crc32 command?
I am using CFG_ENV_ADDR_REDUND, so I guess I have to skip 5 bytes of header.
Do the two last 0x00 count?
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... :-(
--
Steven Scholz
^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot-Users] Verify CRC on environment?
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
0 siblings, 1 reply; 4+ messages in thread
From: Wolfgang Denk @ 2005-05-25 9:12 UTC (permalink / raw)
To: u-boot
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.
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Objects in mirror are closer than they appear.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot-Users] Verify CRC on environment?
2005-05-25 9:12 ` Wolfgang Denk
@ 2005-05-25 9:14 ` Steven Scholz
2005-05-25 9:32 ` Wolfgang Denk
0 siblings, 1 reply; 4+ messages in thread
From: Steven Scholz @ 2005-05-25 9:14 UTC (permalink / raw)
To: u-boot
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
^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot-Users] Verify CRC on environment?
2005-05-25 9:14 ` Steven Scholz
@ 2005-05-25 9:32 ` Wolfgang Denk
0 siblings, 0 replies; 4+ messages in thread
From: Wolfgang Denk @ 2005-05-25 9:32 UTC (permalink / raw)
To: u-boot
In message <429441EA.60203@imc-berlin.de> you wrote:
>
> 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?
Yes.
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"There are three principal ways to lose money: wine, women, and en-
gineers. While the first two are more pleasant, the third is by far
the more certain." -- Baron Rothschild, ca. 1800
^ permalink raw reply [flat|nested] 4+ messages in thread
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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
2005-05-25 9:32 ` Wolfgang Denk
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