[U-Boot-Users] Using NAND with JFFS2.

classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view

[U-Boot-Users] Using NAND with JFFS2.

Woodruff, Richard

Has anyone used adapted/used any of the u-boot JFFS2 code to be NAND aware?
A very quick look at the JFFS2 code (called by fsload, fsinfo, ..) seems to
indicate to me that reading of raw data is done via a straight memcpy
(direct dereference, assuming linear flash).  I'm wondering if making it
work might be as simple as conditionalizing that code to call the nand_mtd
read.j equivalents....unfortunately few things are ever just simple...

The ideal case is to just allow the kernel to be part of the filesytem,
though I suppose it might not be strictly necessary and a raw partition
which ignores bad blocks might be enough....at the moment I'm wondering how
one safely draw the lines of how big a partition would need to be at the
"physical" level to guarantee that your kernel will always fit, assuming
some of the blocks go bad over time.

...I had read at Infradead.org and sort of gathered that the JFFS2 sequence
numbers allows you to write blocks most anywhere as long as the blocks are
contigus...and that when jffs2 comes up it will scan the whole thing
building a proper access map/list.

Any input would be welcomed.


Richard W.