At the core of the Logilab infrastructure is a highly-available pair of small machines dedicated to our main directory and authentication services: LDAP, DNS, DHCP, Kerberos and Radius.
The machines are small fanless boxes powered by a 1GHz Via Eden processor, 512Mb of RAM and 2Gb of storage on a CompactFlash module.
They have served us well for many years, but now is the time for an improvement. We've bought a pair of Lanner FW-7543B that have the same form-factor. They are not fanless, but are much more powerful. They are pretty nice, but have one major drawback: their firmware does not boot on a legacy BIOS-mode device when set up in UEFI. Another hard point is that they do not have a video connector (there is a VGA output on the motherboard, but the connector is optional), so everything must be done via the serial console.
I knew the Debian Jessie installer would provide everything that is required to handle an UEFI-based system, but it took me a few tries to get it to boot.
First, I tried the standard netboot image, but the firmware did not want to boot from a USB stick, probably because the image requires a MBR-based bootloader.
Then I tried to boot from the Refind bootable image and it worked! At least I had the proof this little beast could boot in UEFI. But, although it is probably possible, I could not figure out how to tweak the Refind config file to make it boot properly the Debian installer kernel and initrd.
Finally I gave a try to something I know much better: Grub. Here is what I did to have a working UEFI Debian installer on a USB key.
Partitionning
First, in the UEFI world, you need a GPT partition table with a FAT partition typed "EFI System":
david@laptop:~$ sudo fdisk /dev/sdb
Welcome to fdisk (util-linux 2.25.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): g
Created a new GPT disklabel (GUID: 52FFD2F9-45D6-40A5-8E00-B35B28D6C33D).
Command (m for help): n
Partition number (1-128, default 1): 1
First sector (2048-3915742, default 2048): 2048
Last sector, +sectors or +size{K,M,G,T,P} (2048-3915742, default 3915742): +100M
Created a new partition 1 of type 'Linux filesystem' and of size 100 MiB.
Command (m for help): t
Selected partition 1
Partition type (type L to list all types): 1
Changed type of partition 'Linux filesystem' to 'EFI System'.
Command (m for help): p
Disk /dev/sdb: 1.9 GiB, 2004877312 bytes, 3915776 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 52FFD2F9-45D6-40A5-8E00-B35B28D6C33D
Device Start End Sectors Size Type
/dev/sdb1 2048 206847 204800 100M EFI System
Command (m for help): w
Install Grub
Now we need to install a grub-efi bootloader in this partition:
david@laptop:~$ pmount sdb1 david@laptop:~$ sudo grub-install --target x86_64-efi --efi-directory /media/sdb1/ --removable --boot-directory=/media/sdb1/boot Installing for x86_64-efi platform. Installation finished. No error reported.
Copy the Debian Installer
Our next step is to copy the Debian's netboot kernel and initrd on the USB key:
david@laptop:~$ mkdir /media/sdb1/EFI/debian david@laptop:~$ wget -O /media/sdb1/EFI/debian/linux http://ftp.fr.debian.org/debian/dists/jessie/main/installer-amd64/current/images/netboot/debian-installer/amd64/linux --2016-06-13 18:40:02-- http://ftp.fr.debian.org/debian/dists/jessie/main/installer-amd64/current /images/netboot/debian-installer/amd64/linux Resolving ftp.fr.debian.org (ftp.fr.debian.org)... 212.27.32.66, 2a01:e0c:1:1598::2 Connecting to ftp.fr.debian.org (ftp.fr.debian.org)|212.27.32.66|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 3120416 (3.0M) [text/plain] Saving to: ‘/media/sdb1/EFI/debian/linux’ /media/sdb1/EFI/debian/linux 100%[========================================================>] 2.98M 464KB/s in 6.6s 2016-06-13 18:40:09 (459 KB/s) - ‘/media/sdb1/EFI/debian/linux’ saved [3120416/3120416] david@laptop:~$ wget -O /media/sdb1/EFI/debian/initrd.gz http://ftp.fr.debian.org/debian/dists/jessie/main/installer-amd64/current/images/netboot/debian-installer/amd64/initrd.gz --2016-06-13 18:41:30-- http://ftp.fr.debian.org/debian/dists/jessie/main/installer-amd64/current/images/netboot/debian-installer/amd64/initrd.gz Resolving ftp.fr.debian.org (ftp.fr.debian.org)... 212.27.32.66, 2a01:e0c:1:1598::2 Connecting to ftp.fr.debian.org (ftp.fr.debian.org)|212.27.32.66|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 15119287 (14M) [application/x-gzip] Saving to: ‘/media/sdb1/EFI/debian/initrd.gz’ /media/sdb1/EFI/debian/initrd.g 100%[========================================================>] 14.42M 484KB/s in 31s 2016-06-13 18:42:02 (471 KB/s) - ‘/media/sdb1/EFI/debian/initrd.gz’ saved [15119287/15119287]
Configure Grub
Then, we must write a decent grub.cfg file to load these:
david@laptop:~$ echo >/media/sdb1/boot/grub/grub.cfg <<EOF
menuentry "Jessie Installer" {
insmod part_msdos
insmod ext2
insmod part_gpt
insmod fat
insmod gzio
echo 'Loading Linux kernel'
linux /EFI/debian/linux --- console=ttyS0,115200
echo 'Loading InitRD'
initrd /EFI/debian/initrd.gz
}
EOF
Et voilà, piece of cake!