Patent ID: 8560823

Claim:
A method of securely installing an image update to an electronic device, the method comprising: starting a pre-boot routine; during the pre-boot routine, determining if an update is pending; if an update is not pending, booting normally; and if an update is pending, then activating a signing key, utilizing an image update file stored in a first memory location of the electronic device to install the update to a second memory location of the electronic device, creating an update hash from the update in the second memory location of the electronic device, signing the update hash using the signing key to create a digital signature of the update hash, storing the digital signature of the update hash in a third memory location of the electronic device, deactivating the signing key, after installing the update in the second memory location of the electronic device and storing the digital signature of the update hash in the third memory location of the electronic device, installing, in an atomic operation, i) the update from the second memory location of the electronic device to a boot memory location of the electronic device different from the second memory location of the electronic device, and ii) the digital signature from the third memory location of the electronic device to a known memory location of the electronic device different than the third memory location of the electronic device, causing the electronic device to reboot, verifying a hash of the update using the digital signature, and booting from the update when the hash is verified.