After flasing the Alpine Linux extended ISO, partition a disk. For this action internet is required since `gptfdisk` is not included on the extended ISO, therefore it needs to be obtained from the repository.
The drive should be partitioned using `gdisk` (or `cfdisk`). It should have atleast two partitions with one `EFI System` partition and one `Linux filesystem` partition and look something like this:
| Number of partition | Size | Type |
|:-----:|:-----:|:-----:|
| 1 | 512 MB or more | EFI System |
| 2 | Rest of the drive | Linux filesystem |
Then to create the filesystem on the efi partition.
The root partition of the system is going to be encrypted using `cryptsetup`. First generate a key that will be used to encrypt the device and safe it temporarily to the file `/tmp/crypt-key.txt` with:
Later on in the guide `clevis` will be used for automatic decryption so this key only has to be entered a only few times. However, if any changes are made to the bios or secureboot then this key will be needed again so make sure to write it down.