code/uefi-usb-boot-stick/createboot.md

Creating a bootable USB UEFI stick

Identify the drive

Insert your USB stick and tail /var/log/messages to find out the device name. Then set the device name in a variable

DRIVE=/dev/sdc

Initial formatting of the USB stick

This is a one-time operation. When updating the USB stick this step can be skipped.

Formatting:

• gpt partition table
• primary partition of type ext2
• primary partition of type EFI (EF)
• label /dev/sdc1 as RESCUE

parted ${DRIVE}

Create partitions in parted:

mktable gpt 
mkpart primary ext2 1 512MB
mkpart primary fat32 512MB 1024MB 
set 2 boot on

Format the partitions:

mkfs.ext2 ${DRIVE}1           # this will contain the images. 
mkfs.vfat ${DRIVE}2           # this will contain the UEFI bootloader and grub.cfg
e2label ${DRIVE}1 RESCUE      # label the partition

Synchronize files to the USB stick

Sync images:

mount ${DRIVE}1 /mnt/tmp
mkdir -p /mnt/tmp/images
rsync -av images/ /mnt/tmp/images/
umount /mnt/tmp

Sync the grub configuration:

mount ${DRIVE}2 /mnt/tmp
mkdir -p /mnt/tmp/EFI
rsync -av EFI/ /mnt/tmp/EFI/
umount /mnt/tmp