Forums » Software Development »
Rescanning the Nand flash
Added by Dennis Volper over 13 years ago
I made a type-o when loading the Nand flash. I managed to convince the flash that it has a whole bunch of bad areas. Is there a utility to tell the system to "delete" all bad areas and rescan the flash to see which are really bad?
Replies (1)
RE: Rescanning the Nand flash - Added by John Pruitt over 13 years ago
Dennis,
Just so you know, the suggestions below are not based on personal experience.
Not sure there is a command to do exactly what you are looking for. There is the "nand scrub" command and it comes with a warning:
Warning: scrub option will erase all factory set bad blocks!
There is no reliable way to recover them.
Use this command only for testing purposes if you
are sure of what you are doing!
You could try a "nand bad" or "nand erase" after this to see if it recreates the bad block table. If it doesn't, you probably have to use the "nand markbad" as you find bad blocks. (or if you remember what the factory blocks were, then use that list)
I did try a "nand bad" on a module and it gave messages like:
U-Boot > nand bad
Device 0 bad blocks:
Bad block table not found for chip 0
Bad block table not found for chip 0
Bad block table written to 0x00000ffe0000, version 0x01
Bad block table written to 0x00000ffc0000, version 0x01
0ff80000
0ffa0000
0ffc0000
0ffe0000
U-Boot > nand bad
Device 0 bad blocks:
0ff80000
0ffa0000
0ffc0000
0ffe0000
The first time it said it could not find a bad block table and was writing it. The next time, it did not give these messages so it looks like "nand bad" does more than just list the bad blocks.
Hope this helps.
