Monday, 9 December 2013

Cloud-images: Announcing UEFI and BIOS/GPT images for Trusty

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.14 (GNU/Linux)
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=ZrHB
-----END PGP SIGNATURE-----
Starting with Ubuntu 14.04 LTS, the Cloud Images for AMD64 will include
a new UEFI disk image. This new image has been designed to be as
flexiable as possible, supporting not only UEFI, but BIOS/GPT (current
images are BIOS/MBR) and support for P{V,Y}GRUB's w/ GPT support. As a
result, these new images should work on a variety of hypervisor
platforms. The daily image will be available at [1] once they exit the
build system within the next several hours.

The following output show the layout of the disk:

[email protected]:~$ sudo parted /dev/vda -- print
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags
127 1049kB 2097kB 1049kB BIOS boot partition bios_grub
128 2097kB 89.1MB 87.0MB fat32 EFI System boot
1 89.1MB 10.7GB 10.6GB ext4 Linux filesystem

The layout is explained as followed:
* Partition 127 is for BIOS/GPT booting
* This partition is not mounted.
* Partition 128 is used for the UEFI installation. It is mounted to
/boot/efi
* GRUB UEFI is configured to look at partition 1's /boot/grub/grub.cfg
* UEFI is configured as a removal disk
* In order to register the disk in the hypervisor's NVRAM, you'll
need to run
grub-install again.
* Partition 1 is maintained as the traditional 'cloudimg-rootfs'
* /boot/grub/menu.lst will be maintained for P{V,Y}GRUB.

Note: due to a kernel bug [2], when these images are booted with the
root disk using a virtio device, /dev/vda{127,128} device nodes are not
created. Therefore, for the time being, you will need to use a
non-virtio device in order for these images to boot properly.

Thanks,
Ben


[1]
http://cloud-images.ubuntu.com/trusty/current/trusty-server-cloudimg-amd64-uefi1.img
[2] https://bugs.launchpad.net/bugs/1258631


--


Ben Howard
[email protected]
Canonical
GPG ID 0x5406A866