configuration of devices logically attached to the ISA bus:
* Change the isa_attach_args to have arrays of io, mem, irq, drq
resources.
* Add a "pnpnames" and a linked list of "pnpcompatnames" to the
isa_attach_args. If either of these members are non-NULL,
direct configuration of the bus is being performed. Add an
ISA_DIRECT_CONFIG() macro to test for this.
* Drivers are not allowed to modify the isa_attach_args unless
direct configuration is not being performed and the probe fucntion
is returning success.
* Adapt device drivers -- currently, all driver probe routines return
"no match" if ISA_DIRECT_CONFIG() evaluates to true.
Instead, print a diagnostic and return. (Some drivers do this already.)
Also, normalize the diagnostic message, and fix some places where the
printfs were getting ugly.
- No more distinction between i/o-mapped and memory-mapped
devices. It's all "bus space" now, and space tags
differentiate the space with finer grain than the
bus chipset tag.
- Add memory barrier methods.
- Implement space alloc/free methods.
- Implement region read/write methods (like memcpy to/from
bus space).
This interface provides a better abstraction for dealing with
machine-independent chipset drivers.
a char *, because that's what was really intended, and because
if the print function modifies the string, various things could become
unhappy (so the string should _not_ be modified).
- split softc size and match/attach out from cfdriver into
a new struct cfattach.
- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.
substantial reworking of the multi-port drivers, as they need to frob
bits in the io-port spaces of their children. As a result, the
commulti->com attachment interface is substantially more complex.
(This may be fixable in the future by making some of the code common,
but as long as io-port allocation checking is planned, it's necessary.)
macro where appropriate. No point in hard-coding numbers in multiple places.
At the very least, this makes the drivers slightly easier to diff/understand.
