New features

[joel at oarcorp.com (Joel Sherrill)]

On Tue, 31 Mar 1998, erik.ivanenko wrote:

>  Is anyone interested in loadable device drivers (LDDs) as an RTEMS
> feature?  I for one would very much like to see them implemented, as
> they could simplify application development.  If LDDs were available,
> things such things as analog_input, analog_output, binary_input,
> binary_output network and console drivers could be added/modified while
> leavig the BSP untouched   ( Whenever the BSP is modified, a full
> regression test should really be performed; ie. all SPxx / MPxx retested
> )

This is a very valeable feature.  I think it would be very much
appreciated.

> This could impact how the system  allocates the required amount of
> workspace.


Yes.  But Chris also has a "dynamic allocation" patch which lets you
allocate object in chunks of "maximum_XXX".  So if you configure 10 tasks
with the "dynamic" featuers enabeld, then when you allcoated the 11th, it
would set aside TCBs 11-20.

> Should this feature wait for file-system support?

I think some design work can be done to help identify the features that
are needed.  I am working on the "dirent" support now.  I think RTEMS will
end up with a "mknod" type system call.  If you need anythign else, then
I need to know about it. :)

I have a suspicion that the current IO manager is going to be obsoleted by
the file system work.  Device drivers and names can e registered through
the file system/namespace.

--joel