with the also-experimental ioconf keyword. pseudo-root allows to
specify a root at any point in the device tree without having
attachments from the actual root.
For example, instead of having a config file like this:
mainbus0 at root
bus_a? at mainbus0
bus_b? at bus_a*
device7 at bus_b?
You can have one like this:
pseudo-root bus_b*
device7 at bus_b?
This will produce the relevant ioconf.c glue for device number 7
only instead of the whole 9 yards from root. Perhaps needless to
say, this can be used to generate snippets of config glue for
modules and, let's not deny that my main motivation for doing this,
rump components.
This is part 2/3 of my modifications to config (the last part is
autogenerating source file lists and component Makefiles).
No strong objection from cube (after a little pressuring ;), but
like he said, the implementation will most likely need some more
tweaking and may not work correctly under all pseudo-root uses yet.
o Rework do_kill_orphans() to use that information and mark explicitely
orphaned devices (i.e., the ones whose missing ancestor has been
negated)
o Make a distinction between erroneous orphans and explicit orphans.
Error out on the former, ignore the later (but print a warning when -v
is used)
Yes, now config(1) will actually stop if you comment out a parent. That
should help people still hoping adjustkernel is relevant these days :)
track of instances attaching at root, and walk down the tree of active
device instances. Then, all instances that are not marked active are
found as orphans.
Doing it that way allows us to simply ignore orphan devices, instead of
warning about them and still keep them in the configuration. Now, orphaned
instances are considered as never having existed.
In the end, this allows 'no <device> at <attachment>' to be much more
efficient, as the user doesn't have to negate all descendents of the
instance s/he actually wants to negate. Warnings are still emitted,
though.
While there, make official a side-effect of the previous lack of action
against orphaned instances: config(1) used to warn about instances that
attach at a numbered device when no instance of that device with that
number existed, even though there was a starred instance of the device.
E.g. (provided by Alan Barrett):
pciide* at pci? dev ? function ? flags 0x0000
wdc0 at isa? port 0x1f0 irq 14 flags 0x00
wdc1 at isa? port 0x170 irq 15 flags 0x00
atabus* at ata?
wd0 at atabus0 drive 0
With this commit, config(1) will no longer warn about 'wd0 at atabus0'.
