L4Env Isolating Hard Drives

[Adam Lackorzynski]

On Mon Jul 11, 2005 at 12:38:20 -0400, Julian Grizzard wrote:
> Consider a x86 computer that has two physical IDE hard drives.  Is it
> possible for an L4Env I/O manager to allocate exactly one hard drive
> to an L4Linux2.6 server and allocate the second hard drive to another
> L4 task in a way that the L4Linux2.6 server has no way of knowing that
> the second hard drive exists?

Depends how the drives are connected. If the drives are connected to
two different controllers this can be well done, e.g. by not mapping
mmio areas or not handing out IRQs.
If the drives are connected to the same controller things get more
complicated. One needs an IDE controller driver/server that separates
the drives for different tasks. In L4Linux one now needs a controller
stub driver that talks to the server.




Adam
-- 
Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/