file system

Joel Sherrill joel.sherrill at
Mon Feb 2 18:46:24 UTC 2004

D. Peter Siddons wrote:

> Hi Ed,
>      Thanks for your response, also thanks to Leon Pollack for pointing 
> me towards MicrMonitor.
> The target for my app is the Arcturus uCdimm-5272, which comes with its 
> own rather limited monitor. I had shied away from replacing this with 
> anything else. If nothing else there would be a learning curve plus the 
> odd unbootable card :). It's somehow attractive to just take the 
> commercial part as-delivered, program in the app and off you go. The 
> ideal scenario would then be to have my files tacked on to the bootable 
> RTEMS image and arrange so the app can read them (no writing or deleting 
> needed). I wonder if one could use the IMFS for this? The task would 
> then reduce to pre-formatting the info in the image to look like an IMFS 
> filesystem, wouldn't it? Or am I misunderstanding something?

The easiest way to do this is the same way the httpd network demo does.
There is a nice piece of magic which lets you convert an uncompressed
tar image into an object file.  That object file could then be placed
directly in ROM at a known address or linked into your application.

Either way, you end up calling either rtems_tarfs_load or

int rtems_tarfs_load(char *mountpoint,
                  unsigned char *tar_image,
                  unsigned long tar_size)

rtems_tarfs_load actually leaves the file contents in ROM while
generating the metadata in RAM for the IMFS.  The Untar_fromMemory()
just loads the IMFS image from the tar image.

On a different matter... Ed would it be possible to put together an
RTEMS filesystem plug-in that hooked to the uMon TFS calls?


> Pete.
> Ed Sutter wrote:
>> Pete,
>> I run RTEMS with MicroMonitor underneath.  Provides an immediate
>> flash file system (read/write) for RTEMS-based applications.
>> If you're able to shift to MicroMonitor as your bootloader,
>> let me know and I'll be glad to give you details.
>> Ed Sutter
>> "D. Peter Siddons" wrote:
>>> Hi all,
>>>    I have an RTEMS application which resides in flash memory, and
>>> expects to read a configuration file at startup. It currently does this
>>> via tftp from a networked server, which works fine. I'd really like to
>>> make this thing stand-alone, so ideally it would read this information
>>> from some kind of local filesystem. There is enough capacity in the
>>> on-board flash memory if I could set up a filesystem in there; even more
>>> so if it could be compressed. It need only be read-only. Has anyone else
>>> done something similar? I've seen all the postings re compact flash, but
>>> I don't think that is at all the same.
>>> Thanks,
>>> Pete.
>>> -- 
>>> D. Peter Siddons
>>> Bldg. 725D, NSLS
>>> Brookhaven National Laboratory
>>> Upton, NY 11976
>>> USA.
>>> Email: siddons at

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