Module Name:	src
Committed By:	drochner
Date:		Tue Aug 17 22:13:18 UTC 2004

Modified Files:
	src/sys/kern: subr_autoconf.c
	src/sys/sys: device.h

Log Message:
Add some extensions to the autoconf framework to better support
loadable drivers and user controlled attach/detach of devices.
An outline was given in
http://mail-index.NetBSD.org/tech-kern/2004/08/11/0000.html
To cite the relevant parts:
-Add a "child detached" and a "rescan" method (both optional)
 to the device driver. (This is added to the "cfattach" for now
 because this is under the driver writer's control. Logically
 it belongs more to the "cfdriver", but this is automatically
 generated now.)
 The "child detached" is called by the autoconf framework
 during config_detach(), after the child's ca_detach()
 function was called but before the device data structure
 is freed.
 The "rescan" is called explicitely, either after a driver LKM
 was loaded, or on user request (see the "control device" below).
-Add a field to the device instance where the "locators" (in
 terms of the autoconf framework), which describe the actual
 location of the device relatively to the parent bus, can be
 stored. This can be used by the "child detached" function
 for easier bookkeeping (no need to lookup by device instance
 pointer). (An idea for the future is to use this for generation
 of optimized kernel config files - like DEC's "doconfig".)
-Pass the locators tuple describing a device's location to
 various autoconf functions to support the previous. And since
 locators do only make sense in relation to an "interface
 attribute", pass this as well.
-Add helper functions to add/remove supplemental "cfdata"
 arrays. Needed for driver LKMs.

There is some code duplication which will hopefully resolved
when all "submatch"-style functions are changed to accept the
locator argument.
Some more cleanup can take place when config(8) issues more
information about locators, in particular the length and default
values. To be done later.


To generate a diff of this commit:
cvs rdiff -r1.89 -r1.90 src/sys/kern/subr_autoconf.c
cvs rdiff -r1.68 -r1.69 src/sys/sys/device.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.