Patent ID: 8874892

Claim:
One or more non-transitory machine-readable storage mediums storing one or more sequences of instructions, which when executed, cause: a BIOS analyzing a file to determine whether the file may be used to revert the BIOS to a prior version of the BIOS, wherein the file comprises (a) a copy of the prior version of the BIOS and (b) a map of CMOS information, inserting an empty space signature pattern into a portion of unused space within the prior version of the BIOS to identify whether any alterations have been made to the unused space within the prior version of the BIOS; after the BIOS connects to a network and prior to a loading of an operating system, the BIOS obtaining a checksum from a server over the network used to verify the integrity of the BIOS; after the BIOS verifies that the prior version of the BIOS in the file passes a checksum and certificate comparison using the checksum obtained from the server over the network, the BIOS analyzing the file to determine whether the any alterations have been made to the unused space within the prior version of the BIOS using the empty space signature pattern; and the BIOS only restoring the prior version of the BIOS if the BIOS determines that (a) the prior version of the BIOS passes the checksum and certificate comparison and (b) the BIOS determines no alterations have been made to the unused space within the prior version of the BIOS using the empty space signature pattern; and upon determining that the file may be used to revert the BIOS to the prior version, restoring the prior version of the BIOS and deriving new CMOS values for the prior version of the BIOS using the map of the CMOS information.