Automator Service for Creating MD5 Checksum of Hard Drive

Does anyone know how to make an Automator Service to generate an MD5 Checksum for all files on a Hard Drive? Currently, I have an Automator Service set to Files and Folders with the Application “Finder”, and then the following code in a shell script:

find $1 $2 $3 $4 $5 -type f -exec md5 -r “{}” ; > $1/…/DRIVE.md5

This code allows me to generate MD5 Files of multiple “Folders” within a hard drive or anywhere and then saves the MD5 Checksum file on the Parent Directory. To be safe, I would like to be able to right click the hard drive, select the service and it generate a MD5 checksum of all files and folders on the hard drive while saving the MD5 Checksum file on the hard drive.

Any suggestions or feedback are greatly appreciated! My apologies as I am really new to all of this! Thank you very much!