Hi,

> The only thing that confuses me is that this is an 8bit chip,
> but this ecclayout looks more like a 16bit one than an 8bit one,

The 8, 16 or 64 bits here refer to the size of the OOB area for each
page, not to the chip data bus width: the HY27US08121A has 512 bit pages
with a 16 bit OOB area.

> When I mount the partition I no longer get complaints about bad blocks
> or any of the other odd messages I used to get, but I get no files in
> the partition.  Yet the first block contains the same information it
> has always contained, i.e. the file header for the file "kernel".

Pardon me for the obvious question, but can the board boot routerOS from
the partition you're working with?
Apart from not getting error messages, does df show any bad blocks on
the partition? Is the page containing the kernel header actually marked
as valid (you have to look at the OOB data)?

If df shows bad blocks you have to recreate the data, since it has
probably been destroyed in a previous mount attempt. BTW, it seems that
even when mounting with -o ro pages with bad ECC are marked as
invalid... this sucks.

Andrea