Ask for block cipher AES

As I know, there is block cipher AES in dm-crypt.

When I looked into the documentation of zymkey, there is no block cipher AES.

Do you use the AES software implementation when using the dm-crypt?

How can you control the master key of AES?

I mean that, in normal dm-crypt (luks), the master key is generated from passphrase.

And the software block cipher AES is performed to encrypt all files in raspberry pi.

Is zymkey same?

Our scripts (mk_encr_sd_rfs.sh and mk_encr_ext_rfs.sh) just lock up a LUKS passphrase and then creates the encrypted volume using standard LUKS tools. We let the Raspberry Pi do the rest of the work in dm-crypt.