"Andreas" == Andreas Bießmann andreas.devel@googlemail.com writes:
Hi,
No, please not. Having more than 1 OOB layout on the same NAND device leads to all kind of complications. There has also been kernel patches posted for the ELM, so IMHO the only sane option for am33xx is BCH8 everywhere (with the ROM layout).
Andreas> Ok, I understand your point here. But there are device Andreas> combinations out there that do not match! We have an AM37xx Andreas> with some micron NAND that requires 1bit ECC for the first Andreas> page (if less than 1000 erase cycle). But 4bit ECC for the Andreas> rest of the device. With the 1bit for first page it does fit Andreas> to the ROM requirements of that SoC but unfortunately we can Andreas> not use the same OOB layout on the whole device, cause the ROM Andreas> can only do the 1bit hamming ECC. I think there are other Andreas> boards out there facing the same problem. I have to recheck Andreas> for example the devkit8000 which is a mainlined development Andreas> device some users based their products on (as we do).
Sure, reality tends to be more complicated than that. The different SoCs, Nand devices and projects have different requirements. Notice that this patch is specifically about the Error Location Module present on E.G. am33xx and omap4, where the ROM also uses BCH encoding.