Re: binary drivers and development

[John Richard Moser]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



Peter Chubb wrote:
>>>>>>"John" == John Richard Moser <nigelenki@xxxxxxxxxxx> writes:
> 
> 
> 
> John> I've done more thought, here's a small list of advantages on
> John> using binary drivers, specifically considering UDI.  You can
> John> consider a different implementation for binary drivers as well,
> John> with most of the same advantages.
> 
> Almost all these advantages are also present for user-mode drivers...
> and getting drivers out of the kernel, where possible, is a much
> better approach IMHO than trying to maintain a leaky in-kernel
> interface.  The problem with in-kernel interfaces, even if set in
> concrete, is that any binary driver can go outside the interface ---
> there's no encapsulation --- and so break when the kernel changes.
> 

CPL=3 scares me; context switches are expensive.  can they have direct
hardware access?  I'm sure a security model to isolate user mode drivers
could be in place. . .

. . . huh.  Xen seems to run Linux at CPL=3 and give direct hardware
access, so I guess user mode drivers are possible *shrug*.  Linux isn't
a microkernel though.

> Peter C
> 
> 
> 

- --
All content of all messages exchanged herein are left in the
Public Domain, unless otherwise explicitly stated.

    Creative brains are a valuable, limited resource. They shouldn't be
    wasted on re-inventing the wheel when there are so many fascinating
    new problems waiting out there.
                                                 -- Eric Steven Raymond
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.5 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD4DBQFCMMsGhDd4aOud5P8RAjoOAJ9Owgnd5QOp9MfrQ8PzOLAt/A7k+wCYmxLc
wvXLkQX84Z2PF2J4oEIbVA==
=wi8f
-----END PGP SIGNATURE-----
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/