Some problem in real application
Dear all,
I am new to UBI and want to apply it in a real production application. However, I have a technical problem and hope anyone can give me some advice.
I use NFTL before. While in production, we use some self-made IO programmer to program the NAND flash. We first write the data and ecc (in spare area), and then read then back. After verify it with ECC, we can tell whether the data is written correctly or not.
However, in UBI, it doesn't use spare area and embedded the ECC information in main area. Will it be difficult to extract the ECC information from the read back data in order to do verification? I am worry about our self-made IO programmer is too slow for handling UBI. (Or any other clever way to do that?)
If my question is not clear or even wrong, please point me out. Thanks very much for help.
BR,
Jacky
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Hi,
Theoretically, I cannot respond you because of the silly disclamer you added to the end of your e-mail. However,
Quoted 4 lines · Jacky Lam
I use NFTL before. While in production, we use some self-made IO programmer to program the NAND flash. We first write the data and ecc (in spare area), and then read then back. After verify it with ECC, we can tell whether the data is written correctly or not.
Fine. Just do the same with UBI images.
Quoted 2 lines
However, in UBI, it doesn't use spare area and embedded the ECC information in main area.
UBI itself does not use OOB. But the NAND driver or NAND controller may use it to store ECC codes.
Quoted 2 lines
Will it be difficult to extract the ECC
information from the read back data in order to do verification?
The ECC verification is done in the driver level. UBI is above the driver - it asks the driver to read and write NAND pages. And the driver verifies/calculates ECC codes.
I'm going to update UBI documentation soon and write a little bit more about what the UBI-aware flasher should do. I'll send you a link later.
Signature · 2 lines
Best regards, Artem Bityutskiy (Битюцкий Артём)
Quoted 2 lines · Artem Bityutskiy
I'm going to update UBI documentation soon and write a little bit more about what the UBI-aware flasher should do. I'll send you a link later.
Done. Here are details about how to flash UBI images properly:
http://www.linux-mtd.infradead.org/doc/ubi.html#L_format_det
Signature · 2 lines
Best regards, Artem Bityutskiy (Битюцкий Артём)
A message that is not in the archive (sent off-list or not yet received): [email protected]
Quoted 2 lines · Jacky Lam
That means I can still use nanddump utility to extract the nand
raw image and put it back to a blank new flash?
I think so. But read the link I sent you.
Signature · 2 lines
Best regards, Artem Bityutskiy (Битюцкий Артём)