NAND Flash filesystem
mickd at goanna.iinet.net.au
Tue Oct 19 06:51:49 UTC 2010
Yes, good progress.
I have a basic working bsp for the at91sam9263-ek. It might be a good
time to share it so that others can contribute, but I still have
improvements to make.
For the NAND filesystem, I'm currently on the route of adapting UFFS.
I've built it as a library for RTEMS, which involved creating a makefile
and supplying some functions to the library from RTEMS. That part was
In my app, I then had to write hardware interface functions. These are
specific to the atmel processors, and require some config for the NAND
chips you want to support. I should move them into the BSP I guess.
I've been testing with the UFFS API, and so far it seems good. It
doesn't lose files and handles bad blocks. I don't have performance
figures yet, but there's no noticeable startup delay, which was a
concern for the 512Mb+ chips I'm working with.
I haven't made a lot of progress with integrating UFFS into the RTEMS
filesystem. I've had a look at the RTEMS Filesystem Design Guide. I've
been looking at how the ftp and tftp filesystems do it, because they're
similar. I don't have blocks or nodes, just filenames and directories,
and handles for open files.
I can see how to setup with the mount table and that I need to supply
functions for the rtems_filesystem_operations_table and
rtems_filesystem_file_handlers_r structures. It's not clear to me
what's then expected of the functions I write. I'd also like to
understand what sequence the functions are used in.
I've actually been testing without UFFS at all to get things worked out.
It should be possible to develop a model for how to integrate a
generic file + directory names filesystem.
On 18/10/10 21:19, Sebastian Huber wrote:
> Hello Mick,
> have you made some progress with your flash file system issues?
> Have a nice day!
Goanna Technologies Pty Ltd
+61 8 9444 2634
"Shock your lizard today!"
More information about the users