NanoBSD (8.1-STABLE): can not boot with boot0sio & can not change boot0cfg / active partition

[M. Warner Losh]

In message: <642536497.20100929133254 at serebryakov.spb.ru>
            Lev Serebryakov <lev at FreeBSD.org> writes:
: Hello, Freebsd-embedded.
: 
:   I have two problems with NanoBSD built from 8.1-STABLE sources
: 
:   (1)    I    have  serial console configured for speed 115200. I have
:   "BOOT_COMCONSOLE_SPEED=115200"  setting,  but  boot0sio hangs. "mbr"
:   works  fine,  but  "boot0cfg"  can  not change booting slice in this
:   case.
: 
:   (2)  When  I  try  to use fdisk to change booting slice ("fdisk -1 -a
:   ad0")  it  complains after all questions (why, oh, why fdisk doesn't
:   have "not ask anything" mode WITHOUT config file?!):
: 
: Should we write new partition table? [n] y
: fdisk: Class not found
: fdisk: Failed to write sector zero
: hostname#
: 
:   boot0cfg can not install boot0sio too:
: 
: hostname# boot0cfg -B -b /boot/boot0sio ad0
: boot0cfg: write_mbr: /dev/ad0: Operation not permitted
: hostname#
: 
:  So,  I  can  not  upgrade  NanoBSD  in-place,  because I can not swap
:  bootable partition :(

doesn't "gpart -a active -i 1 ad0" work?

Warner