Hi again, Thanks to all for your answers. After further investigation I don't seem to actually need disk access/a file system by now, so I'll leave this thread of work for the moment.
Thanks again, María. On Fri, Jun 20, 2014 at 12:02 PM, Martin Schröder <martin.schroe...@openlimit.com> wrote: > Am 19.06.2014 18:06, schrieb Jorge Ventura: > >> This is a good direction. I forgot that, in reality we need two drivers, >> one for a block device and another one for the filesystem itself. >> > > The two drivers are not sufficient if the underlying hardware is some sort > of bare flash devices (NOR, NAND) and you use a traditional file system. The > number of erase cycles of an individual block is limited. So writes of > frequently written blocks (directory, file allocation table) need to be > evenly spread over the device to avoid a premature death of vital blocks. > This is the so called wear levelling which is an additional driver in > between the block device driver and the file system driver. Or you use a > file systems which incorporates wear levelling (JFFS2, UBIFS). > > The two drivers are sufficient only if the underlying hardware is an > intelligent device like a hard disk, SSD, SD card or USB Stick. Such devices > have their own controller performing wear levelling itself. > > > Martin > > > _______________________________________________ > l4-hackers mailing list > l4-hackers@os.inf.tu-dresden.de > http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers _______________________________________________ l4-hackers mailing list l4-hackers@os.inf.tu-dresden.de http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers
