kern/59913: NetBSD bootblocks don't pass long volume names

["john%ziaspace.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         59913
>Category:       kern
>Synopsis:       NetBSD bootblocks don't pass long volume names
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jan 12 20:15:00 +0000 2026
>Originator:     John Klos
>Release:        NetBSD 11.0_BETA
>Organization:
	
>Environment:
	
	
System: NetBSD bunny.zia.io 11.0_BETA NetBSD 11.0_BETA (BUNNY) #0: Wed Oct 15 11:51:33 UTC 2025 john%bunny.zia.io@localhost:/usr/obj-amd64/sys/arch/amd64/compile/BUNNY amd64
Architecture: x86_64
Machine: amd64
>Description:
	
When using boot.cfg to tell the kernel where to root, old fashioned
BIOS boot blocks don't pass names longer than ten characters.
>How-To-Repeat:
	
On a system with MBR / BIOS bootblocks, edit /boot.cfg and add
something like this:

menu=Boot normally:rndseed /var/db/entropy-file;root NAME=longvolumename;boot

While booting, before the kernel loads, the bootblock reports:

truncated to NAME=longvolume

The kernel reports:

boot device: <unknown>
>Fix:
	
1) pass a longer string for root and boot, if possible

2) when evaluating the boot device from what's passed from bootblocks with
string limits, perhaps match with the first NAME that matches (although this 
could be problematic if people use longvolumenamea, longvolumenameb, et cetera)

3) perhaps make a hash of the NAME and compare it with hashes of all available
volume names and match based on that, if the 10 character limit can't be fixed

4) document the limitation in (5) boot.cfg

>Unformatted: