Date: Sat, 30 Apr 2011 19:39:09 +0200 From: rank1seeker@gmail.com To: freebsd-hackers@freebsd.org Subject: Re: Look of boot2, on HDD Message-ID: <20110430.173909.578.1@DEV> In-Reply-To: <4DBC3D63.6020508@FreeBSD.org> References: <20110429.160309.656.1@DEV> <mailpost.1304116761.7079263.67267.mailing.freebsd.hackers@FreeBSD.cs.nctu.edu.tw> <4DBC3D63.6020508@FreeBSD.org>
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----- Original Message -----
From: Alexander Motin <mav@FreeBSD.org>
To: freebsd-hackers@freebsd.org
Date: Sat, 30 Apr 2011 19:48:35 +0300
Subject: Re: Look of boot2, on HDD
> Garrett Cooper wrote:
> > 2011/4/29 <rank1seeker@gmail.com>:
> >> /boot/boot2 STAGE 2 bootstrap file
> >> Understands the FreeBSD file system enough, to find files on it, and can provide a simple interface to choose the kernel or loader to run.
> >>
> >> Once sys is fully booted, HDD is 'ada0'.
> >> However, STAGE 2, sees it, as a 'ad4', at boot process, which is same seen, by booted sys, when I turn off AHCI.
> >>
> >> So, here is the riddle ...
> >> On fully booted sys, how do I query STAGE 2, to tell me, how it'll see, my 'ada0' HDD?
> >
> > This is a very interesting catch:
> >
> > /usr/src/sys/boot/pc98/boot2/boot2.c:static const char *const
> > dev_nm[NDEV] = {"ad", "da", "fd"};
> > /usr/src/sys/boot/i386/boot2/boot2.c:static const char *const
> > dev_nm[NDEV] = {"ad", "da", "fd"};
> >
> > It probably will be a no-op soon because of some of the
> > compatibility changes Alex made, but still a potential point of
> > confusion nonetheless.
>
> Pardon my ignorance, but could somebody shed some light for me on this
> list of names? Why much more sophisticated loader(8) operates disks as
> diak0/1/..., while boot2 tries to mimic something he has no any idea
> about, using very limited information from random sources? Does this
> names important for anything?
>
> Even with old ATA names didn't match on my laptop: boot2 reports ad0,
> while system - ad4. Also we have a lot of drivers who's disk names don't
> fit into this set of ad, da and fd.
>
> --
> Alexander Motin
Well ..., ATM, I say lets NOT touch/edit boot2 nor loader.
Let them continue to see devices, the way they "like" ...
NOW, all I would like, is to find a way of ASKING them, how will they see "$target" device, at theirs boot step/time.
"Asking" is done, on a fully booted sys and I am interested in asking STAGE 2 (boot2).
Domagoj Smolčić
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