systemd-boot-system-token.service - Generate an initial boot loader system token and random seed
systemd-boot-system-token.service is a system service that automatically generates a 'system token' to store in an EFI variable in the system's NVRAM and a random seed to store on the EFI System Partition ESP on disk. The boot loader may then combine these two randomized data fields by cryptographic hashing, and pass it to the OS it boots as initialization seed for its entropy pool. The random seed stored in the ESP is refreshed on each reboot ensuring that multiple subsequent boots will boot with different seeds. The 'system token' is generated randomly once, and then persistently stored in the system's EFI variable storage.
The systemd-boot-system-token.service unit invokes the bootctl random-seed command, which updates the random seed in the ESP, and initializes the 'system token' if it's not initialized yet. The service is conditionalized so that it is run only when all of the below apply:
For further details see bootctl(1), regarding the command this service invokes.
- Boot Loader Interface