Testing EFI integrity under Linux
is it available for Linux too?


It's highly unlikely to be available in Linux.  

This is a macOS utility to improve the security of Apple Mac products.  Apple typically doesn't make available (aka open source) the tools they develop as they are proprietary to Apple.  There's no incentive for them to port this (or any other utility) to Linux since it's Apple's objective for you to run macOS on Apple hardware.