External RAM filesystem

Aitor.Viana.Sanchez at esa.int Aitor.Viana.Sanchez at esa.int
Fri Nov 16 17:04:44 UTC 2007


OK the problem eventually was only half mine ;). I'll try to explain.

The LEON2 board i got has 64MB of SDRAM memory placed in the address 
0x60000000, and I want to locate the ramdisk filesystem within that area.

The configuration is:

        rtems_bdbuf_config rtems_bdbuf_configuration[] = {
          { 512, numberOfBlocks, (unsigned char *) _SDRAM_FS_ADDR }
        int rtems_bdbuf_configuration_size = 1;

        rtems_ramdisk_config rtems_ramdisk_configuration[] = {
          {512, numberOfBlocks, (void *) _SDRAM_FS_ADDR}

where _SDRAM_FS_ADDR is 0x60000000 and numberOfBlocks is the size of the 
filesystem i want to placed divided by 512 (which is the block size), 
        #define _FILESYSTEM_SIZE                        (0x1000000)     // 
        static unsigned int numberOfBlocks = (_FILESYSTEM_SIZE / 512);

The problem is that, with this numberOfBlocks  value, RTEMS is not able to 
mount the filesystem, raising an error. The error shows up when 
msdos_format() is called, returning "not such file or directory". On the 
contrary, if numberOfBlocks = 40 (for instance) everything goes well.

Is there any limitation within RTEMS w.r.t. the size of the filesystem?

thanks in advanced.


Aitor Viana Sánchez

ESA - European Space Technology Centre (ESTEC)
TEC-EDD - Computer and Data Systems Section
ESA/ESTEC P.O. Box 299 / 2200AG Noordwijk ZH, The Netherlands
Tel (+31) 71 565 6727
Email: aitor.viana.sanchez at esa.int

Thomas Doerfler <Thomas.Doerfler at embedded-brains.de> 
Sent by: rtems-users-bounces at rtems.org
11/15/2007 09:54 PM

Aitor.Viana.Sanchez at esa.int
rtems-users at rtems.org
Re: External RAM filesystem


Aitor.Viana.Sanchez at esa.int schrieb:
> Hi,
> I got everything ready to send an example and to include a wiki entry
> but fist...the example is only working in rtems- I also
> tried with RTEMS 4.6.5 but looks like some functions are not implemented
> in this version. This is the compilation output.

ys you are right, I implemented the msdos_format function somewhere
after 4.6.5, so you might have missed it in that version.



The module should be back-portable if required, but there might be some
other unresolved references then.

Are you currently stuck to 4.6.5 in your work? Which architecture are
you working on?


Embedded Brains GmbH
Thomas Doerfler           Obere Lagerstr. 30
D-82178 Puchheim          Germany
email: Thomas.Doerfler at embedded-brains.de
Phone: +49-89-18908079-2
Fax:   +49-89-18908079-9
rtems-users mailing list
rtems-users at rtems.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/users/attachments/20071116/f6568258/attachment-0001.html>

More information about the users mailing list