Reading through the manual, I'm finding mysterious mention of the use of crypto with grub. eg. section 11.1, "How to specify devices" mentions (crypto0) or (cryptouuid/xxxxxxxxxxx) specifications.
I'm also seeing modules in my /boot/grub (Ubuntu) that are undocumented in the manual, but include "crypto.mod" and a "gcry_xxxx.mod" that indicate many crypto operations.
I am used to having to unlock crypto disks through user-space operations that take place through programs that are embedded in an initramfs, so I'm curious about what all these modules do or what use specifying crypto devices might be. Can someone direct me to documentation?
More generally, there are a bunch of other modules in my /boot/grub that are undocumented. I'd like to know more about what they do.