Dual Boot 8.2 and Windows 7
Gyrd Thane Lange
gyrd-se at thanelange.no
Tue Jun 28 02:10:10 UTC 2011
On Tue, 28 Jun 2011 01:52:16 +0200
Gyrd Thane Lange <gyrd-se at thanelange.no> wrote:
> On Mon, 27 Jun 2011 09:56:51 -0700
> perryh at pluto.rain.com wrote:
> > Gyrd Thane Lange <gyrd-se at thanelange.no> wrote:
> > > On Fri, 24 Jun 2011 16:47:26 -0700
> > > perryh at pluto.rain.com wrote:
> > >
> > > > ... The code in i386/boot2 and
> > > > lib/libstand is written to find the / (or /boot) FS on a
> > > > BSD partition of an fdisk "primary partition" (aka slice),
> > > > or in a GPT partition, and would need additions to handle
> > > > fdisk "extended partitions".
> > >
> > > Some years ago I ran into a similar problem. I ran out of primary
> > > partitions (using MBR-speak) and had to move FreeBSD into an
> > > extended partition.
> > >
> > > Here the simple patch I wrote for the FreeBSD boot loader:
> > > <http://parvati.thanelange.no/freebsd/boot_loader/boot_loader.diff>
> > > <http://parvati.thanelange.no/freebsd/boot_loader/>
> > Any thought of submitting that as a PR?
> I've always meant to submit it as a PR, but found the send-pr(1) too
> daunting. (It is impossible/undesirable for me to have a working mail
> sender on my system and I have not yet found a way for send-pr(1) to
> work in offline mode for delayed sending by a different machine.) I
> suppose I could give the HTML version a try...
kern/158358: [patch] allow /boot/loader to work from an MBR extended
> > > The next challenge is to find a boot manager that will pick up
> > > FreeBSD in an extended partition. For myself I use a self patched
> > > GRUB. (GRUB also nearly worked out of the box, but had a different
> > > problem.)
> > It makes sense that GRUB would understand "extended partitions"
> > since its roots are in Linux which is often installed in extended
> > partitions. Ideally FreeBSD should have a native solution, i.e.
> > a version of boot2 that would understand extended partitions.
> > Dunno without trying it if the capability could be added to the
> > existing boot2 without exceeding available space, or if it would
> > need a new variant.
> I agree that would have been more convenient, but since MBR is going
> the way of the dodo I haven't looked that closely into it.
> > > You're welcome to have those patches as well if you need them.
> > It would be good to get them posted somewhere. GRUB is not in the
> > FreeBSD tree AFAIK, so send-pr is likely not all that good a method,
> > but perhaps they could be pushed upstream to the GRUB maintainers?
> The problem with GRUB was computing the correct absolute start sector
> of FreeBSD partitions, as in bsdlabel(8), when they resided in
> "extended partitions". More details are available as comments in the
> All that's required is to drop the file into:
> and then build the port, install grub, e.t.c.
> I can make a PR for it against the sysutils/grub port. I'll also look
> into how to push it upstream.
I have filed the following PR:
ports/158362: sysutils/grub [patch] allow GRUB to boot FreeBSD from an
While doing so I discovered another one with a similar theme.
ports/152389: sysutils/grub and sysutils/grub2 misinterpret disklabels
created with bsdlabel
More information about the freebsd-questions