9.0 and bsdinstall - avoiding updating the MBR
Ian Smith
smithi at nimnet.asn.au
Mon Nov 21 16:50:17 UTC 2011
In freebsd-questions Digest, Vol 390, Issue 1, Message: 18
On Mon, 21 Nov 2011 01:47:27 +0000 Bruce Cran <bruce at cran.org.uk> wrote:
> I'm planning to install FreeBSD alongside a whole range of Windows
> builds for testing. In 8.x it's possible to tell the installer not to
> bother updating the MBR so you can use something like EasyBCD to boot it
> via the Windows bootloader instead. Is it still possible on 9.0-RC2
> using bsdinstall? I don't seem to remember seeing any option to avoid
> writing out the new boot code.
Hi, I gather not (yet?) Can save the MBR with (eg) 'boot0cfg -f ~/mymbr
adaX' for safety, dd it back if need be, and/or use fdisk(8) -p, -t and
-f flags to save, test and restore just the slice table.
At least they're precautions I'm taking, really not wanting to clobber
win2k (for BIOS updates :), 8.2-RELEASE or a shared UFS partition when
next trying to install 9.0-RC2 to slice 2, currently 7.4-RELEASE ..
% boot0cfg -v ad0
# flag start chs type end chs offset size
1 0x00 0: 1: 1 0x0b 1023: 5:63 63 8385867
2 0x00 1023:255:63 0xa5 1023: 13:63 8385930 125821080
3 0x00 1023:255:63 0xa5 1023: 15:63 134207010 33543342
4 0x80 1023:255:63 0xa5 1023: 14:63 167750730 66685815
version=2.0 drive=0x80 mask=0xf ticks=182 bell=# (0x23)
options=packet,update,nosetdrv
volume serial ID a8a8-a8a8
default_selection=F4 (Slice 4)
% fdisk -p ad0
# /dev/ad0
g c232581 h16 s63
p 1 0x0b 63 8385867
p 2 0xa5 8385930 125821080
p 3 0xa5 134207010 33543342
p 4 0xa5 167750730 66685815
a 4
cheers, Ian
More information about the freebsd-questions
mailing list