This re-implements the custom serial concept in a new way. This way
doesn't touch any of the backend code, it just introduces a optional
redirection layer in the existing serial backends.
This implementation supports more serial operations to, so we can
support more backends this way.
Hooking into the existing serial backends might look ugly but its
probably the best way to make sure this patch conflicts as little as
possible with upstream.
Signed-off-by: Anton Lundin <glance@acc.umu.se>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
An application can now register an application defined callback
function, which will perform the actual logging. This provides
additional flexibility compared to logging to stderr with a hardcoded
format. Applications can now easily display the messages in their user
interface, customize the format, etc.
Although the internal logging function is a printf like function, the
arguments are converted into a plain string before being passed to the
callback function. This greatly improves interoperability with
programming languages which don't support C style variadic functions
(e.g. Python, C#, etc).
With the introduction of a context object, library initialization and
shutdown can be performed without requiring any global state. A single
process can use multiple independent contexts without any problems. The
lack of a global state also improves the thread-safety of the library.
At the moment, the new context object is primary used to implement an
improved logging system.
