Add a new low-level device API to Termios that passes the TTY structure
to the low-level device functions. This greatly simplifies the
low-level device drivers since they are no longer forced to derive their
private data from the minor number.
It makes it possible to use the TTY low-level lock in the device driver
low-level functions which is necessary for proper SMP support. For
example to set the attributes it is often necessary to perform a
read-modify-write operation on a control register used also by interrupt
routines.
A compatibility layer is provided to support device drivers using the
old callback functions so it is not necessary to modify existing device
drivers.
This directory contains tests for some of the items in
the lib directories. The intent is to be able to
verify the basic functionality of a library. For example,
it is important to know that the stack checker successfully
detects tasks which both stay within and exceed their
stack limits.