Shell – How to create bootable flash for “efi-shell”

bootshelluefi

Current Intel server chipsets include a built-in "efi-shell" which appears to basically be a simplified 'NIX with a command set suitable for manipulating some nifty UEFI boot options.

It is also the case that some of Intel's firmware upgrade tools now require "efi-shell" to run.

Sadly, I do not have a server chipset even though this board does support UEFI booting.

The efi-shell can be downloaded from http://www.sourceforge.net/projects/efi-shell. However, I can find no bootable ISO or any other form of bootable image.

I have attempted to make a bootable flash with unetbootin with no success.

Any thoughts on how I might make a copy of efi-shell bootable so I can run the Intel firmware upgrade on my RAID card?

Best Answer

Just drop this binary into that flash drive FAT's root directory (or maybe EFI/BOOT/ subdirectory, depends IIRC) under the name of shellx64.efi, or get yourself a copy of refind usbflash image which would also serve as a decent boot manager.

Related Solutions

How to make UEFI bootable usb disk from bios bootable iso

Some magic of El Torito is required when creating the iso image. See this.

EFI Boot – How to Recreate EFI Boot Partition

I don't know why you're using grub in the first place. UEFI acts as a boot loader and it allows to select different operating systems or individual kernels from a boot menu. Although there are some exceptions, it usually is not required to chain a second boot loader, grub in this case.

You mention, you installed elementary OS instead of Fedora, which means you only need to load one operating system. Here I present a way to do it without using grub. The kernel needs to be compiled with EFI_STUB, if that's the case you can check with

grep EFI_STUB /boot/config-<version>

Copy the kernel and initramfs to the ESP (EFI system partition)

cp /boot/vmlinuz-<version> /boot/efi/EFI/elementary/vmlinuz-<version>.efi
cp /boot/initrd.img-<version> /boot/efi/EFI/elementary/initrd.img-<version>

Register kernel as boot option in UEFI

echo "root=UUID=<disk_uuid> ro quiet rootfstype=ext4 add_efi_memmap initrd=\\EFI\\elementary\\initrd.img-<version>" |
  iconv -f ascii -t ucs2 |
  efibootmgr \
    --create --gpt \
    --disk /dev/<disk> --part <partition_number> \
    --label "Elementary OS" \
    --loader "\\EFI\\elementary\\vmlinuz-<version>.efi" \
    --write-signature --append-binary-args -

The --disk argument takes the device name of the disk, e.g. --disk /dev/sda, the --part argument takes the partition number of the ESP, e.g. 4. You can find the ESP partition number with the following command:

gdisk -l /dev/sda | awk '$6=="EF00" {print $1}'

Ensure that you repeat the steps after each kernel update

Either you this manually (just repeat the steps above) or you write a small script which does the job. To fully automatise it, the script could be hooked into the kernel post-install procedure, into the initramfs post-update procedure and into the kernel postrm procedure (to remove the UEFI boot entry). Actually, I don't know why this isn't done by default in the distributions, it's just a few lines of code.