Binary package “arm-trusted-firmware” in ubuntu lunar
"secure world" software for ARM SoCs - firmware
The "secure world" on arm64 machines is a special level of CPU
privilege that is hidden from the normal OS, and has complete
control over the system. It provides both initialization during
early boot stages (before u-boot or EFI) and system monitor
functionality once the machine is booted up.
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This package includes the firmware binaries.