Problem booting ("cannot mount root, error = 79")

[Silas Silva <silasdb%gmail.com@localhost>]

Hello all.

I just sup'ed the -current sources, compiled it and tried to replace my
current system (NetBSD 4.0) following instructions in
http://www.netbsd.org/docs/current/index.html.

Compilation worked fine, but the kernel stops at the boot, with the
following error message:

boot device: wd0
root on wd0a dumps on wd0b
no file system for wd0b
cannot mount root, error = 79
root device (default wd0a):

wd0a is ok, because it works well with 4.0 kernel. I saw that some
changes were made in src/sys/kern/vfs_subr.c, in the vfs_mountroot()
function last days.

Does anybody know anything about it? Some critical changes was made that
I don't know? BTW, is there a list of incompatibility between two NetBSD
versions?

GENERIC kernel, i386 here.

Thank you very much.

-- 
Silas Silva