Re: loader.conf and rootdev option for memory disk

On Sat, Nov 19, 2022 at 6:01 PM Tomoaki AOKI <junchoon@dec.sakura.ne.jp>
wrote:

> But your previous post shows rootdev= there didn't work, and needed
> setting vfs.root.mountfrom=.
>
> OTOH, rootdev= is reported to work in efi/boot/freebsd/loader.env (with
> efi loader) on freebsd-users-jp ML (as it's Japanese ML, in Japanese)
> this year.
>
> So /boot/defaults/loader.conf (/usr/src/stand/defaults/loader.conf)
> should be fixed, and what should be set in loader.env should be
> documented.
>
>  *Dedicated brand-new manpage or in boot.8 (or in loader.8 describing
>   rootdev, or loader.conf.8 in contrast with itself).
>

Reading the code it's complicated.

rootdev looks like it overrides the default root... unless
vfs.root.mountfrom
has already been set.


>
> On Sat, 19 Nov 2022 22:31:42 +0100
> Chlasták Miroslav <mira@chlastak.cz> wrote:
>
> > Look at the file /boot/defaults/loader.conf:
> >
> > …
> > ###  Initial memory disk settings  ###########################
> > #mdroot_load="YES"              # The "mdroot" prefix is arbitrary.
> > #mdroot_type="md_image"         # Create md(4) disk at boot.
> > #mdroot_name="/boot/root.img"   # Path to a file containing the image.
> > #rootdev="ufs:/dev/md0"         # Set the root filesystem to md(4)
> device.
> > …
> >
> > —
> > Mira
> >
> > > On 19 Nov 2022, at 21:58, Tomoaki AOKI <junchoon@dec.sakura.ne.jp>
> wrote:
> > >
> > > IIUC, rootdev should be set in loader.env, if needed.
> > > `man 5 loader.conf` has nothing about rootdev variable.
> > >
> > > (It's undocumented, IIRC.)
> > >
> > >
> > > On Sat, 19 Nov 2022 19:57:47 +0100
> > > Chlasták Miroslav <mira@chlastak.cz <mailto:mira@chlastak.cz>> wrote:
> > >
> > >> I have my device working for now - but the question is - Is the
> documentation and example for “rootdev” right or not?
> > >>
> > >> —
> > >> Mira
> > >>
> > >>> On 18 Nov 2022, at 21:13, Warner Losh <imp@bsdimp.com <mailto:
> imp@bsdimp.com>> wrote:
> > >>>
> > >>>
> > >>>
> > >>> On Fri, Nov 18, 2022 at 12:57 PM Chlasták Miroslav <mira@chlastak.cz
> <mailto:mira@chlastak.cz> <mailto:mira@chlastak.cz <mailto:
> mira@chlastak.cz>>> wrote:
> > >>> Hi all,
> > >>>
> > >>> In the /boot/defaults/loader.conf are these options for memory disk
> settings:
> > >>>
> > >>> #mdroot_load="YES"              # The "mdroot" prefix is arbitrary.
> > >>> #mdroot_type="md_image"         # Create md(4) disk at boot.
> > >>> #mdroot_name="/boot/root.img"   # Path to a file containing the
> image.
> > >>> #rootdev="ufs:/dev/md0"         # Set the root filesystem to md(4)
> device.
> > >>>
> > >>>
> > >>> But - is this example for rootdev option still right? Because
> “ufs:/dev/md0” works fine on freebsd 12.1, but on freebsd 12.3 this does
> not work and generates error message:
> > >>>
> > >>> Can’t determine root device
> > >>>
> > >>>
> > >>> When I use this option with value “/dev/md0” or “md0” (even with
> this option commented out), so the machine boots correctly without any
> error.
> > >>>
> > >>> I think you want vfs.root.mountfrom= instead of rootdev= here.
> > >>>
> > >>> Warner
> > >>>
> > >>> —
> > >>> Mira
> > >>
> > >
> > >
> > > --
> > > 青木 知明  [Tomoaki AOKI]    <junchoon@dec.sakura.ne.jp <mailto:
> junchoon@dec.sakura.ne.jp>>
> >
>
>
> --
> 青木 知明  [Tomoaki AOKI]    <junchoon@dec.sakura.ne.jp>
>
>