Apparatus for determining during a power-on sequence, a value to be written to a first register in a secure area and the same value to a second register in non-secure area, which during a protected mode, the value is compared such that if it is equal, enabling writing to a memory
US8495354B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 2008 |
| Grant date | Jul 23, 2013 |
| Priority date | — |
| Expiry date | Dec 28, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/572
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Systems and methods of securely updating BIOS are disclosed. One such system comprises a reprogrammable memory, a first and a second register, and comparison logic. The reprogrammable memory comprises a first portion and a protect input. The protect input is configured to disallow writes to at least the first portion when the memory protect input is at a first level, and to allow writes to at least the first portion when the protect input is at a second level; The comparison logic is configured to drive a comparison output to a third level responsive to the first and second registers having equal values, and to drive the comparison output to a fourth level responsive to the first and second registers having different values. The comparison output is electrically coupled to the memory protect input.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.