JFFS2 on SPI Flash

[Ricard Wanderlof]

On Wed, 19 Dec 2007, Duke wrote:

> Can anyone offer any thoughts?
>
> On 12/18/07, Duke <ezbonites at gmail.com> wrote:
>> Hi, If I choose to have a JFFS2 fs on SPI flash device, what is the 
>> minimum size required? For example a 16Mbit ST chip has a sector size 
>> of 512K bit while the Atmel 16Mbit (AT45DB..) has a sector size of 
>> 128Kbytes.  Is there a rule of tumb to apply for making th choice?

If you have a look in the kernel 
fs/jffs2/build.c:jffs2_calc_trigger_levels() you can get an idea about how 
much free space you need to do things like delete a file, or write to the 
file system. Basically, two free blocks are needed to delete files, to 
write, the number of blocks depends on the partition size and the number 
of blocks in the partition.

/Ricard
--
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30