Patent ID: 6968450

Claim:
A disk drive connectable to a host computer, the disk drive comprising: (a) a disk for storing initial host requested (IHR) data requested by the host computer during a start-up process of the host computer; (b) a head actuated radially over the disk; (c) a non-volatile semiconductor memory (NVSM) for caching at least part of the IHR data; and (d) a disk controller for performing a mechanical initialization process for the disk drive and for transmitting the IHR data to the host computer during the start-up process by: enabling the disk drive to receive a read command from the host computer before completing the mechanical initialization process; receiving the read command from the host computer to read the IHR data; if the IHR data is cached in the NVSM, transmitting the cached IHR data from the NVSM to the host computer; and if the IHR data is not cached in the NVSM: waiting for the mechanical initialization process to complete; reading the IHR data from the disk; and transmitting the IHR data to the host computer, wherein: the start-up process begins in connection with an operating system boot of the host computer; the IHR data comprises operating system boot data; the IHR data comprises a plurality of IHR data blocks requested in a sequence by the host computer during the start-up process; and when the sequence of IHR data blocks requested by the host computer changes, the disk controller re-allocates a block of the NVSM storing a later requested IHR data block cached in the NVSM in order to cache an earlier requested IHR data block in the NVSM.