From: Mike Gilbert <floppym@gentoo.org>
To: gentoo-user@lists.gentoo.org
Subject: Re: [gentoo-user] Re: Using UUID for root disk in grub requires initramfs?
Date: Fri, 19 Jul 2019 12:59:09 -0400 [thread overview]
Message-ID: <CAJ0EP42Tke29rPDDJRKhv6ubU2nRXLFmCi8p26yODa9b5RDQ9Q@mail.gmail.com> (raw)
In-Reply-To: <20190719163716.l6lkpnwlrcxg3353@matica.foolinux.mooo.com>
On Fri, Jul 19, 2019 at 12:37 PM Ian Zimmerman <itz@very.loosely.org> wrote:
>
> On 2019-07-19 20:58, Adam Carter wrote:
>
> > I experimented found the following worked in /etc/default/grub;
> >
> > GRUB_DEVICE="PARTUUID=d3554d49-02"
> >
> > Which writes grub.cfg as;
> > linux /vmlinuz-5.2.0-gentoo root=PARTUUID=d3554d49-02 ro
> > init=/usr/lib/systemd/systemd iommu=pt raid=noautodetect
> >
> > PARTUUID looked up with blkid. No initramfs required :)
>
> I don't get this. blkid is userspace. The _kernel_ needs to know what
> the root fs device is, before it even starts pid 1.
The kernel init code is able to find a device given its PARTUUID.
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/init/do_mounts.c?h=v4.19.59#n172
next prev parent reply other threads:[~2019-07-19 16:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-19 9:29 [gentoo-user] Using UUID for root disk in grub requires initramfs? Adam Carter
2019-07-19 10:27 ` Mick
2019-07-19 10:58 ` Adam Carter
2019-07-19 16:37 ` [gentoo-user] " Ian Zimmerman
2019-07-19 16:59 ` Mike Gilbert [this message]
2019-07-19 23:19 ` Adam Carter
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