libio preparation for file systems

[Quality Quorum]

> 
> 
> Hi,
> 
> I am beginning to look at adding the infrastructure for
> a more robust name space in RTEMS.  libio was orignally
> designed to map device names into major/minor pairs and
> pass IO request through to device drivers.  Since that
> time, it has been augmented to support sockets.
> 
> I would like to start getting the infrastructure in place
> to be able to mount file systems, walk directory trees
> of "/dev", etc.  Essentially have a better "logical
> file system."
> 
> Right now, I am looking at the way this is done in various
> free UNIces (Linux and NetBSD).  I would like suggestions
> on what capabilities you folks would like to see in
> this area.  If you have ideas about possible implementations 
> we could look at.
> 
> I hope this opens a discussion.

Oh, please, let us keep it as simple as moo. Simplicity and performance
are at premium in embedded world - and they will suffer as a
result of improving device abstractions.

Just as an exmaple count what percentage of file I/O flags is not
supported  currently by /dev/console. It is OK as long as we all
implicitly know what console can and cannot do, but once we will get
into device abstraction, all devices would have to support common 
functionality, which can (a) affect performance, (b) be a severe 
overkill in many many cases.


> --joel


Aleksey