MicroMonitor TFS & RTEMS

Ed Sutter esutter at lucent.com
Tue Sep 28 19:47:49 UTC 2004

Yep, that works fine too.  That's what I was using until
this point.  I bit the bullet and wrote the driver after getting
the pointer to tftpDriver.c from Joel and seeing that it would
be a pretty easy hookup.  Plus now, use of TFS immediately becomes
compatible with other standard apps in RTEMS.

> We are booting into micromonitor and running RTEMS with our app.  We are
> using the micromonitor TFS instead of incorporating a flash file system
> into RTEMS.  We then use micromonitor calls to handle all flash access.
> At 10:28 AM 9/28/2004, Ed Sutter wrote:
> > > >All,
> > > >Last night I took Joel's advice (from a while ago) and used the
> > > >tftpDriver.c code as a model for integrating TFS into RTEMS as
> > > >a mountable FS.  I shamelessly reused a good portion of the
> > > >generic parts of the code in tftpDriver.c (in places simply
> > > >changing _tftp_ to _tfs_).  At first glance, it appears to be
> > > >working fine, and now I can access TFS files through RTEMS's FS.
> > > >
> > > >So, assuming there must be more to it (it just can't be that easy!),
> > > >what kind of limitations are imposed by this interface?  I see
> > > >there is a limited number of interfaces (no ioctl, fstat,
> > > >etc...), but I hope to eventually get that stuff working.
> > > >Are there any other "gotchas" I need to be aware of for
> > > >integrating TFS into RTEMS as a mountable FS?
> > > >
> > > I don't know TFS -
> >
> >Quick description:
> >TFS (Tiny File System) is a major component in a boot monitor that I wrote
> >called MicroMonitor.  As a part of the monitor, it provides a very
> >maintainable
> >(IMHO) platform for an embedded system.  TFS, to be honest, isn't really a
> >file system, rather it provides a power-safe means to organize on-board
> >flash into name space, but still allows the user to access the data at the
> >raw memory level.  The TFS API gives the appearance of an FS (read,
> >write, open, close, ctrl, stat, seek, etc...) but under the hood it's just
> >a glorified linked list, with code that deals with flash defragmentation
> >in a powersafe way.
> >
> > > It's desirable to support directory lookup and fstat.
> > > Without directories, 'pwd' won't work.
> > > Existing software often also uses seek.
> >
> >Ok, that sounds reasonable.  TFS doesn't have a directory heirarchy;
> >however, I think (?) it will be easy to fake this.  The fstat and seek
> >functionality is already in TFS's API, so that should easily hook into
> >
> >Thanks!
> >Ed
> Steve Holle
> Link Communications, Inc.
> 1035 Cerise Rd.
> Billings, MT  59101
> sholle at link-comm.com

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