2011/9/22 Wolfgang Denk <[email protected]>: > Dear Arno Steffen, > > In message > <CAACX+R3ep2g0eytXC=u8gacjgrg9h3f5qukgq1t4mhuykwa...@mail.gmail.com> you > wrote: >> >> This is a good advice - I will check this next. Thanks, Scott! >> I use an OMAP3 (simular to EVM 3530 board) with uboot-2010.03. >> My assumption of not using ECC (or doing CRC first) is derived from, >> that I had several devices with CRC error in environment but not even >> a single board ever complains about the kernel, which is 12x bigger! >> (It is from what I know also CRC protected, but in another way). From >> my knowledge about statistics this behaviour is very unlikely. > > Eventually the ernel got written a lot less frequently than the > environment blocks - I would not be surprised if you are just > experiencing the "normal" wear of NAND blocks. > > [And keep in mind that NAND also develops erros when you only read > it.] > > 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: [email protected] > I'm frequently appalled by the low regard you Earthmen have for life. > -- Spock, "The Galileo Seven", stardate 2822.3 >
I think I have the proof, that ECC is not working on my OMAP. This might be a configuration problem or whatever - so I don't blame it on the uboot itselft, but what? I have here 2 failing devices: uboot gives me a CRC error or bad NAND. While nanddump (running from linux) gives me nanddump -p /dev/mtd2 -f /tmp/env_crc_dump.txt ECC failed: 0 ECC corrected: 2 Number of bad blocks: 0 Number of bbt blocks: 0 Block size 131072, page size 2048, OOB size 64 Dumping data starting at 0x00000000 and ending at 0x00040000... ECC: 1 corrected bitflip(s) at offset 0x00012800 There is one strange issue: It gives 0 errors and 2 corrections, but only reports 1 corrected bitflip. While dumping this with and without ECC I could indeed identify a bit: -0x00012e60: 00 00 00 00 00 00 00 80 00 00 00 00 00 00 00 00 +0x00012e60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Another device gives me anddump -p -f /tmp/crc_env.txt /dev/mtd2 ECC failed: 0 ECC corrected: 0 Number of bad blocks: 0 Number of bbt blocks: 0 Block size 131072, page size 2048, OOB size 64 Dumping data starting at 0x00000000 and ending at 0x00040000... ECC: 1 corrected bitflip(s) at offset 0x0000a800 While dumping this with and without ECC I could indeed identify a bit: -0x0000a8d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +0x0000a8d0: 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 Best regards Arno _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
