Implementing upcall from secure to non-secure mode by injecting exception into non-secure mode
US9465617B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2015 |
| Grant date | Oct 11, 2016 |
| Priority date | — |
| Expiry date | Jun 29, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2009/45579
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system that does not natively support non-maskable interrupts (NMIs) implements NMI-like functionality in a secure monitor. The computer system detects a high priority interrupt and determines whether or not interrupts are enabled or disabled. If interrupts are enabled, the computer system injects an exception into a currently executing thread of system software operating at the second privilege level, and an exception handler processes the exception like a standard exception. If interrupts are disabled, the computer system saves the current system state (e.g., the current program counter and CPU state) and values of one or more exception handling registers in temporary storage and injects an exception into the currently executing thread of the system software, and the exception handler processes the exception in a special manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.