diskimage-builder/diskimage_builder/elements/ubuntu-common
Steve Baker 27a326dafb Support secure-boot bootloader where possible
As of grub2 >= 2.02-95 on redhat family distros, calling grub2-install
on an EFI partition will fail with: "this utility cannot be used for
EFI platforms because it does not support UEFI Secure Boot."

This version of grub is now in centos8-stream and non-eus repos of
RHEL-8. It is not currently possible to build whole-disk UEFI images
on these distros, and when this package is promoted this will also
affect centos8 and RHEL-8 eus. The grub maintainers made this change
because the grub2-install generated /boot/efi/EFI/BOOT/BOOTX64.EFI
will never be capable of booting with Secure Boot.

This change defines a $EFI_BOOT_DIR for every distro element. When
directory /boot/efi/$EFI_BOOT_DIR exists a grub.cfg file in will be
generated there. This change also installs the shim package on redhat
family distros, which installs a copy of the shim bootloader to
/boot/efi/EFI/BOOT/BOOTX64.EFI. Using centos as an example, this
allows UEFI to boot the shim /boot/efi/EFI/BOOT/BOOTX64.EFI which
then chains to /boot/efi/EFI/centos/grubx64.efi.

If /boot/efi/$EFI_BOOT_DIR doesn't exist (such as for Ubuntu,
/boot/efi/EFI/ubuntu) the current behaviour of running grub-install to
generate /boot/efi/EFI/BOOT/BOOTX64.EFI will continue. For distros
such as Ubutnu where packaging does not populate /boot/efi/EFI/ubuntu
with .efi files, secure boot can be added in the future by copying
.efi files to /boot/efi/EFI/ubuntu and copying the shim file to
/boot/efi/EFI/BOOT/BOOTX64.EFI.

Change-Id: I90925218ff2aa4c4daffcf86e686b6d98d6b0f21
2021-03-11 10:27:59 +13:00
..
environment.d Support secure-boot bootloader where possible 2021-03-11 10:27:59 +13:00
install.d Merge branch 'master' into merge-branch 2017-02-09 13:35:53 +11:00
README.rst Merge branch 'master' into merge-branch 2017-02-09 13:35:53 +11:00
element-deps Clear /etc/machine-id to avoid duplicate machine-ids 2017-08-06 13:56:58 -04:00

README.rst

ubuntu-common

This element holds configuration and scripts that are common for all Ubuntu images.