Providing core root of trust measurement (CRTM) for systems using a backup copy of basic input/output system (BIOS)
AssigneeInternational Business Machines Corporation
InventorsRichard A. Dayan, Scott N. Dunham
Life of this patent
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Abstract
A flash memory is provided that includes a primary flash bank and a secondary flash bank. The primary flash bank includes CRTM logic and BIOS logic and the secondary flash bank comprises a backup copy of the CRTM logic and the BIOS logic. A switching mechanism is configured to selectively activate the primary flash bank or the secondary flash bank.
Claims20
A computer system, comprising:
- a flash memory including a primary flash bank and a secondary flash bank, wherein the primary flash bank comprises Core Root of Trust Measurement (CRTM) logic and Basic Input/Output System (BIOS) logic and the secondary flash bank comprises a backup copy of the CRTM logic and the BIOS logic;
- and
- a switching mechanism configured to selectively activate the primary flash bank or the secondary flash bank.
A method for providing Core Root of Trust Measurement (CRTM) within a computer system having a backup copy of Basic Input/Output System (BIOS) logic, comprising:
- receiving an indication that the computer system is being powered on;
- selectively activating either a primary flash bank having CRTM logic and BIOS logic stored therein or a secondary flash bank having a backup copy of the CRTM logic and BIOS logic stored therein;
- passing control of the computer system to the CRTM logic and then the BIOS logic of the selectively activated flash bank;
- activating the non-selected flash bank in response to the BIOS logic within the selected flash bank failing to execute to completion;
- and
- passing control of the computer system to the CRTM logic and then the BIOS logic in the newly activated flash bank.
A computer-readable medium storing computer instructions for providing Core Root of Trust Measurement (CRTM) within a computer system having a backup copy of Basic Input/Output System (BIOS) logic, the computer instructions when executed by the computer system carry out the following steps:
- receiving an indication that the computer system is being powered on;
- selectively activating either a primary flash bank having CRTM logic and BIOS logic stored therein or a secondary flash bank having a backup copy of the CRTM logic and BIOS logic stored therein;
- passing control of the computer system to the CRTM logic and then the BIOS logic of the selectively activated flash bank;
- activating the non-selected flash bank in response to the BIOS logic within the selected flash bank failing to execute to completion;
- and
- passing control of the computer system to the CRTM logic and then the BIOS logic in the newly activated flash bank.
Dependencies are inferred from the claim text.