Support missing initrd types under initrd/bin/unpack_initramfs.sh `type 02214c18b266` will be subject to another PR down the path..

[tlaurion]

@JonathonHall-Purism what on hell is type 02214c18b266 will be subject to another PR down the path...
It's LZ4. > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/decompress.c#n58

We'd need to ship an LZ4 decompressor (if we don't already), then add it to unpack_initramfs.sh: https://github.com/linuxboot/heads/blob/master/initrd/bin/unpack_initramfs.sh#L67.

Originally posted by @JonathonHall-Purism in #1644 (comment)

[tlaurion]

There is also Tails reporting this one:

Add missing decompression methods

[tlaurion]

I could only test xz, which I added under #1860