On Sun, 8 Feb 2004, David Young wrote:

> A word about testing bus barriers: I keep coming back to this idea
> of producing a "virtual bus" which either simulates a bus or else
> filters/logs/re-orders I/O before passing it through to a physical bus.
> An overlay bus that re-orders I/O under the constraints set by explicit
> bus barriers would be useful for stressing a device driver to find bugs
> in the placement of barriers. An overlay bus could reverse I/O, say,
> or randomize it, whenever barriers did not forbid it.
>
> (Another use of virtual buses is device simulation. With a virtual bus,
> one can simulate some subset of a device's register set, or else simulate
> an ethernet NIC's descriptor rings, et cetera, in order to test the
> units of a device driver.)

I really like this idea.

-- 
Gillette - the best a man can forget