Rong Shen wrote:
>> This would miss certain classes of error - such as charge leakage (e.g.
>> the cells will erase or set themselves over a day/week/month/year).
>>
>> http://lists.openmoko.org/pipermail/community/2007-July/008471.html
So, from what I understand of this message, the BBT is first generated
by a capable bootloader (which the RouterBOARD doesn't have) out of the
factory and then regenerated when necessary by Linux when errors are
detected? Neat...
> You are probably right on this, but no one can guarantee a good block
> will never turn to bad block, even most of manufactures would say in
> their datasheet that bad blocks may develop later on. So if there's no
> 100 percent reliable way to detect bad blocks, why don't we try the
> above process, which can at least detect non-intermittent errors.
Isn't this how the scanner in the Linux kernel works anyway? From the
code...
/* Compare the pattern */
for (i = 0; i < td->len; i++) {
if (p[td->offs + i] != td->pattern[i])
return -1;
}
return 0;
and this is simply run at boot time. I don't see the harm in
implementing something similar to that in a memtest86 fashion. Or am I
missing something here?
With regard to the 'uncorrectable errors', is there still a chance that
there's a driver problem if the ECC layout allows the filesystem to be
mounted correctly? (That said - mtdblock0 contains an ELF image of a
Linux kernel, not a filesystem, and mtdblock1 contains the Yaffs
filesystem itself. I'm not sure this matters though...) I'll try to
search around and see if I can force those blocks to be reprobed or so.
Anyway, thanks for the tips! Since the device is non-critical, I'm
considering just wiping it and dealing with the consequences if they pop
up. I'll have a look at the Hynix docs before doing so just to make
sure, as suggested.
Regards,
Noah
- --
Noah Fontes
Cynigram
http://www.cynigram.com/
Phone: +1 919 349 9826
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