Re: [9fans] porting from vs. porting to Plan 9

[Charles Forsyth <forsyth@caldo.demon.co.uk>]

>>It might be possible to construct a cage such that Linux drivers could
>>be compiled and run in Plan 9 kernels without causing too much damage
>>to the running system.

i'd have thought it would be harder to encapsulate the drivers
than user-level code, but since no one has tried, we don't really
know.  one result of attempting it would be a possibly useful
comparison between Linux and Plan 9 kernel internals and interfaces.
(currently, my favourite examples are drivers for non-x86
platforms that must produce x86-defined values for higher levels.)

the Linux driver interfaces are supposed to have changed significantly in 2.6
according to the Linux glossy magazine i bought recently.  i haven't yet
looked at the code.  the catch in using 2.6 as a basis is that i suspect many drivers
haven't been converted.  either that, or there's nothing to
convert because it hasn't really changed.

for useful drivers, is xBSD really well behind Linux?
i'd have thought encapsulating a BSD one would be easier,
if it's possible at all,
if only because BSD started with a Unix model so the pitfalls
are fairly obvious to start with.

perhaps more to the point, which missing drivers in particular
have provoked the crisis?  has it just built up?

Linux itself is having trouble with hot plugging things, if my recent
experience with Redhat is any guide.  actually, it was cold plugging
things: i had to take one card out because it couldn't drive it at all
and put in a card that i thought it could drive (sound familiar?).
admittedly i got it to work in the end but only because i
kept thumping it and correcting it each time it
went wrong.  (``which ethernet was that again?''
i don't know: you've got the PCI vendor/device ID database! look it up!)
it was worse than Windows.  Windows seems to
specialises in drivers that must (or must not) be installed
before (or after) installing the device.  read the bits of paper
carefully!  don't panic!  don't hit the computer!
``i've already given you the bloody driver disk!  THERE IS THE DRIVER!''
(my 2000 hasn't really recovered from the Bluetooth experience.
i myself have barely recovered.)   i can only assume there are nasty
things to sort out that are hard to get right that we've avoided only
because we haven't done this sort of thing.  either that or there
are surprisingly many twits writing code.