fix 'cd' driver's NCD_SCSI bogosity (was using testing wrong macro!)
clean up in various ways:
* make common atapi_mode_{sense,select}() functions.
* put ATAPI data structures in more sensible headers, split up by
device type.
* include headers a bit more carefully.
* pass flags to attachment-specific cd functions, and use them.
* get rid of SCSI bits in scsipi_base.h's scsipi_make_xs(), move
them into the correct place in scsi_base.c.
* fix minor typo in struct name in scsipiconf.h (which was apparently
never used except in a #define later in the same file).
* use __attribute__ to force 4-byte alignment for xs command store,
so that architectures trying to bus_space_write_multi_N() (where
N > 1) that data to a controller won't lose.
* clean up a few comments in typos, and make a few #defines easier to
understand/maintain.
* rename cd_link.h to cdvar.h (via repository copy). This is exactly
what a 'var' file is supposed to be.
* Fix bug in wdc that would overflow ATAPI transfer length.
* Improve wdc probe code so that 'wdc' is probed in if present
even if there are no drives attached, and so that it works
properly even if the only device is an ATAPI slave.
* bus_space-ify.
* split the ISA attachment from the wdc driver, and remove
ISA dependencies from non-ISA files.
* claim that wd and wdc are now machine-independent (probably not
completely true, but mostly so; they at least work on arm32 and
i386).
* Various other minor fixups and cleanups, some of which were pointed
out by Kazuki Sakamoto.
now lives in dev/ic, wd now lives in dev/ata. there's now a 'ata'
interface attribute defined in conf/files, but wdc can't go there
yet because some ports still use private versions based on the old
ISA version.
-base address 0x308 is supported by more Wangtek QIC tapes than 0x300
-Ultrastor ISA SCSI adapters can't be set to base address 0x334
(changed to 0x340)
written by chuck cranor. thanks to mycroft for helping me find the
one little line of code i accidentally deleted while merging it.
this is not enabled by default. `options MACHINE_NEW_NONCONTIG'
will use this code. eventually, this should go into <machine/vmparam.h>
insteaed of MACHINE_NONCONTIG.
cgd