The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 2019
Filed:
Jun. 30, 2017
Phoenix Technologies Ltd., Campbell, CA (US);
Kenneth C. Taylor, Kirkland, WA (US);
James L. Mortensen, Lynnwood, WA (US);
Phoenix Technologies Ltd., Pasadena, CA (US);
Abstract
Approaches for securing a host machine against security attacks conducted using Direct Memory Access (DMA). Platform firmware does not enable bus mastering during PCI bus enumeration. When the platform firmware determines that an expansion card has been plugged into an expansion card slot of the host machine, the platform firmware determines whether the expansion card slot has been approved by a user of the host machine for permitting Direct Memory Access (DMA) with the host machine. Unless the expansion card slot has been determined to be approved by the user for permitting Direct Memory Access (DMA) with the host machine, the platform firmware does not allow drivers that might enable DMA to connect to the device and does not grant permission to the expansion card slot and any upstream bridges to conduct Direct Memory Access (DMA) with the host machine.