kern/175671: BOOTP_NFSROOT option is effectively "always on"

[Ian Lepore]

>Number:         175671
>Category:       kern
>Synopsis:       BOOTP_NFSROOT option is effectively "always on"
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Jan 29 12:50:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Ian Lepore <ian at freebsd.org>
>Release:        FreeBSD 10.0-CURRENT
>Organization:
Symmetricom, Inc.
>Environment:
FreeBSD dpnand 10.0-CURRENT FreeBSD 10.0-CURRENT #9 r246001M: Tue Jan 29 05:33:08 MST 2013     root at revolution.hippie.lan:/local/build/staging/freebsd/dp10/obj/arm.arm/local/build/staging/freebsd/dp10/src/sys/DP-NFSROOT  arm

>Description:
When the BOOTP option is included in the kernel config, the system will not
boot unless the server provides a root path.  The presence or absence of
the BOOTP_NFSROOT and ROOTDEVNAME= options has no effect on this behavior.

It should be possible to specify BOOTP and ROOTDEVNAME without BOOTP_NFSROOT
so that the kernel obtains IP-related information from the server and then 
mounts root from the path specified with ROOTDEVNAME.  It may be reasonable 
and useful to use any server-provided path as a fallback if ROOTDEVNAME 
doesn't work (i.e., store the server-provided name in rootdevnames[1]).

>How-To-Repeat:
	

>Fix:
	


>Release-Note:
>Audit-Trail:
>Unformatted: