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.schroeder@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
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