Chapter 6. Filesystem support

The NAND driver provides all necessary functions for a filesystem via the MTD interface.

Filesystems must be aware of the NAND peculiarities and restrictions. One major restrictions of NAND Flash is, that you cannot write as often as you want to a page. The consecutive writes to a page, before erasing it again, are restricted to 1-3 writes, depending on the manufacturers specifications. This applies similar to the spare area.

Therefore NAND aware filesystems must either write in page size chunks or hold a writebuffer to collect smaller writes until they sum up to pagesize. Available NAND aware filesystems: JFFS2, YAFFS.

The spare area usage to store filesystem data is controlled by the spare area placement functionality which is described in one of the earlier chapters.