Re: Viengoos resource management

[olafBuddenhagen]

Hi,

On Wed, Oct 15, 2008 at 04:22:45PM +0530, Shakthi Kannan wrote:

> I would like some information on Viengoos resource management.

See Neal's diploma thesis,
http://plato.walfield.org/20080729-walfield-viengoos-thesis-final.pdf

> Is Viengoos written from scratch over L4 or any existing L4
> implementations have been re-used?

I don't understand the question. Viengoos currently (mis-)uses L4
(Pistachio) as a hardware abstraction, but doesn't use any of it's
interesting features (IPC, memory mapping etc.); instead, Viengoos does
all the interesting stuff itself -- it's really almost a complete
microkernel itself.

Using L4 as hardware abstraction is not ideal of course, but as Viengoos
is presently only a prototype used for research work, this is good
enough. If Viengoos is ever to be used more seriously, it would be
desirable to replace the L4 dependency by native code of course.

> Is there any other reason other than non-secure IPC in L4 that
> prompted to write Viengoos?

Well, note that Viengoos is mostly about resource management, which is
pretty much out of the scope of L4...

I think IPC/mapping had to be redone not only because of lack of
protected IPC in the original L4 (and other issues like problems with
the purely sync IPC) -- which are important for a system like the Hurd,
though really unrelated to the resource management -- but also because
the resource management needs some low-level support not present in the
L4 mechanisms.

-antrik-