From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=)
Subject: bug#21843: Generated grub.cfg does not support encrypted roots
Date: Thu, 10 Mar 2016 10:17:46 +0100
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References: <87twozi0ql.fsf@gnu.org> <20160308192104.GA22722@solar>
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To: Andreas Enge <andreas@enge.fr>
Cc: 21843@debbugs.gnu.org

Andreas Enge <andreas@enge.fr> skribis:

> What is needed are the following two lines at the beginning of grub.cfg:
>
> insmod luks
> cryptomount -u 1aa...
>
> where 1aa... is the result of "cryptsetup luksUUID /dev/sda2".
>
> So the logic outlined in my previous message works:
> Determine the mapped-devices /dev/sdXY of type luks-device-mapping that
> lead to a file-system with needed-for-boot? set to #t.
> Using
>    cryptsetup luksUUID /dev/sdXY
> determine a corresponding uuid 12345...0.
> If any such mapped-device exists, add
>    insmod luks
> as the first line of grub.cfg. For any such mapped-device, add a line
>    cryptomount -u 12345...0
> right after that.

IIUC we don=E2=80=99t *have* to pass the UUID to =E2=80=98cryptomount=E2=80=
=99; we could also
pass the device name, in GRUB format, which would allow us to use the
same strategy as in =E2=80=98grub-root-search=E2=80=99 in (gnu system grub)=
=E2=80=A6 with the
difficulty that we=E2=80=99d have to be able to map Linux /dev node names to
GRUB device names.

Furthermore, to allow users to specify a LUKS UUID as the =E2=80=98source=
=E2=80=99 of
their =E2=80=98mapped-device=E2=80=99 form, as in:

   (mapped-device
     (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44")) ;LUKS UUID
     (target "root")
     (type luks-device-mapping))

we=E2=80=99d have to extend <mapped-device-kind> with a method to resolve U=
UIDs
(in this case, to map a UUID to a /dev node.)

Thoughts?  Looks like more work than I initially thought.

Besides, I think we should only worry about the mapped device(s) that
back / and /boot, rather than any mapped device, no?

Thanks for looking into it,
Ludo=E2=80=99.