added required packages apart from ubuntu server standard

README.md

@@ -4,8 +4,16 @@ The utility installs a Disk encryption key in the TPM and unencrypts the disk au
 The settings for trusted boot differ for the various Linux distros and releases.
 This version is tested for Ubuntu 20.04 LTS. It requires TPM-Tools 4.x as the parameters completely changed from 3.x
 
+## Prerequisities
+Tested system: Ubuntu 20.04 LTS with encrypted root partition.
+Required additional packages:
+- binutils (for objcopy, generating unified Kernel)
+- tpm2-tools
+- auditd (for logging syscalls of processes)
+- attr (for accessing security.ima file attribute)
+
 ## Usage
-1. Install Ubuntu 20.04 with Full Disk Encryption.
+1. Install Ubuntu 20.04 with Full Disk Encryption with the additional packages.
 1. Execute install.sh
 2. Reboot the machine, you will still be asked for your encryption passphrase
 3. Update the TPM PCR policy with update-luks-tpm.sh