Create UEFI secureboot USB

This article explains how to create an UEFI boot USB with parted and gummiboot.

In this example we will use /dev/sdX. This will be different depending on your system.

Create GPT boot partition

apk add parted

Create a single UEFI boot partitions.

Warning: This will erase all content of your /dev/sdX. Make sure that you use correct device.

parted --script /dev/sdX mklabel gpt parted --script --align=optimal /dev/sdX mkpart ESP fat32 1MiB 100% parted --script /dev/sdX set 1 boot on

Create fat32 filesystem

Create a fat32 system with the name `Alpine`.

mkfs.vfat -n ALPINE /dev/sdX1

Copy content of ISO image to filesystem

It is possible to mount the iso image and copy files with cp or rsync and it is also possible to use 7z to extract content from the iso. In this example I will use the uniso utility from alpine-conf package.

mount -t vfat /dev/sdX1 /mnt cd /mnt uniso < /path/to/alpine-3.8.2-x86_64.iso

Create MOK Key

openssl req -new -x509 -newkey rsa:2048 -keyout "$USER"_local.key -out "$USER"_local.crt -nodes -days 3650 -subj "/CN=$USER/" openssl x509 -in "$USER"_local.crt -out "$USER"_local.cer -outform DER

Copy signed shim

Install gummiboot

Unmount the partition

Finally umount the disk

cd ~ && umount /mnt