>If I compile a kernel consisting solely of those devices
>detected by GENERIC, with NO OTHER CHANGES, I get the
>following panic:
>	root on wd0a dumps on wd0b
>	init: copying out patch '/sbin/init'
>	panic: cnopen: cn_tab->cn_dev == NODEV
>and the machine reboots.  How very strange.  The GENERIC
>kernel boots happily.  Note that I do not have a wd0b
>partition at all.  Kernel config files available on request.

	you really need to send the kernel configuration file...
	it is not clear for readers what you meant with "with NO OTHER CHANGE".

	didn't you remove your console devices from the configuration file?
	you need a console device at least.

itojun