ostree-grub-generator can be used to customize
the generated grub.cfg file. Compile time
decision ostree-grub-generator vs grub2-mkconfig
can be overwritten with the OSTREE_GRUB2_EXEC
envvar - useful for auto tests and OS installers.
Why this alternative approach:
1) The current approach is less flexible than using a
custom 'ostree-grub-generator' script. Each system can
adjust this script for its needs, instead of using the
hardcoded values from ostree-bootloader-grub2.c.
2) Too much overhead on embedded to generate grub.cfg
via /etc/grub.d/ configuration files. It is still
possible to do so, even with this patch applied.
No need to install grub2 package on a target device.
3) The grub2-mkconfig code path has other issues:
https://bugzilla.gnome.org/show_bug.cgi?id=761180
Task: https://bugzilla.gnome.org/show_bug.cgi?id=762220Closes: #228
Approved by: cgwalters
Since we hard-depend on GLib 2.40, we can start using GSubprocess.
This is part of dropping our dependency on libgsystem, which is
deprecated in favor of libglnx (as well as migrating things to GLib).
The original intention here was that we'd keey around a copy of the
file so that grub2 could eventually learn how to do atomic updates by
checking for a "fully written" marker in the *new* file, and if it
didn't exist, falling back to grub2.cfg.old.
I haven't yet proposed that upstream, but we might as well stop
deleting the file since it's useful as a backup at least.
Reported-by: Gatis Paeglis
In Anaconda, we're using "ostree admin --sysroot=/mnt/sysimage
instutil set-kargs", and it was working before, but newer versions of
lorax strip out /etc/system-release which grub2 wants.
That was wrong anyways as we want the /etc/system-release from the
target root.
(Man, grub2 sucks...give me a declarative config file format I can just
write)
https://bugzilla.gnome.org/show_bug.cgi?id=740697
We need basic support for UEFI - many newer servers don't support
BIOS compatibility mode anymore.
However, this patch only implements non-atomic because UEFI is FAT, and
we can't do the previous design for OSTree of atomic swap of
/boot/loader.
The Fedora/RHEL UEFI layout has the kernels on a "real" /boot
partition, and /boot/efi/EFI/$vendor just holds the grub2 UEFI binary
and grub.cfg.
Following this, /boot/loader is still on the OS boot partition, and we
still atomically swap it. This potentially paves the way to atomic
upgrades in the future.
https://bugzilla.gnome.org/show_bug.cgi?id=724246
In this approach, we drop a /etc/grub.d/15_ostree file which is a
hybrid of shell/C that picks up bits from the GRUB2 library (e.g. the
block device script generation), and then calls into libostree's
GRUB2 code which knows about the BLS entries.
This is admittedly ugly. There exists another approach for GRUB2 to
learn the BLS specification. However, the spec has a few issues:
https://www.redhat.com/archives/anaconda-devel-list/2014-July/msg00002.html
This approach also gives a bit more control to the admin via the
naming of the 15_ostree symlink; they can easily disable it:
Or reorder the ostree entries ahead of 10_linux:
Also, this approach doesn't require patches for grub2, which is an
issue with the pressure to backport (rpm-)OSTree to EL7.
Gatis Paeglis
Colin Walters
Matthew Barnes