Abstract: Method and system for controlling areas of memory within a computer system to routines executing at a specific privilege levels in a modern computer architecture featuring protection keys, operating-system-routine calls and interrupts result in promotion of the current privilege level to the highest privilege level prior to dispatch to an operating system routine with concomitant demotion of the CPL to operating-system-privilege level. By partitioning the 24-bit protection queue space into multiple protection-key domains, each protection-key domain associated with a privilege level, and by invalidating protection-key registers during each protection of the current privilege level to a higher privilege level, regions of memory are provided that can only be accessed by routines running at low privilege levels and by routines at the highest privilege level, but not accessible to routines running at intermediate privilege levels.

Abstract: A combined-hardware-and-software secure-platform interface to which operating systems and customized control programs interface within a computer system. The combined-hardware-and-software secure-platform interface employs a hardware platform that provides at least four privilege levels, non-privileged instructions, non-privileged registers, privileged instructions, privileged registers, and firmware interfaces. The combined-hardware-and-software secure-platform interface conceals all privileged instructions, privileged registers, and firmware interfaces and privileged registers from direct access by operating systems and custom control programs, providing to the operating systems and custom control programs the non-privileged instructions and non-privileged registers provided by the hardware platform as well as a set of callable software services.

Abstract: A system monitors the execution of privileged instructions by a processor of a computer system. The processor includes a current privilege level. The processor automatically generates a fault when attempting execution of an instruction requiring a higher privilege level than the current privilege level of the processor. The current privilege level of the processor is raised in response to a fault generated by a first faulting instruction. The first faulting instruction is executed. A trap is generated by executing the first faulting instruction. The current privilege level of the processor is lowered in response to the trap.

Abstract: A system monitors unaligned memory accesses by a processor of a computer system. The processor automatically generates a fault when attempting an unaligned memory access. Unaligned memory access faults are disabled in response to a fault generated by a first faulting instruction. The first faulting instruction is executed. A trap is generated by executing the first faulting instruction. Unaligned memory access faults are enabled in response to the trap.

Abstract: A digital image capture device including circuits capable of measuring the distance between the image capture device and an imaged object allows the capture of three-dimensional data of the surface of the object facing the image capture device. The distance data is obtained by the addition of a flash unit, and very high resolution timers to multiple pixels within the image capture device to measure the time required for the flash to reflect from the object. Since the speed of light is constant, the distance from the flash to the object to the image capture device may be calculated from the delay for the light from the flash to reach the device. Multiple pixels may be used to construct a three-dimensional model of the surface of the object facing the image capture device. Multiple images including distance data may be taken in order to generate a complete three-dimensional model of the surface of the object.

Abstract: A method and apparatus virtualizes file access operations and other I/O operations in operating systems by performing string substitutions upon a file paths or other resource identifiers to convert the virtual destination of an I/O operation to a physical destination. A virtual file system translation driver is interposed between a file system driver and applications and system utilities. The virtual file system translation driver receives file access requests from the applications and system utilities, and translates the file path to virtualize the file system. In a first embodiment, the file system is partially virtualized and a user can see both the virtual file paths and the physical file paths. In second and third embodiments, the file system is completely virtualized from the point of view of the applications and system utilities. In the second embodiment, a user may start with a physical file system, and virtualize the file system by installing the virtual file system translation driver.

Abstract: A method and apparatus virtualizes file access operations and other I/O operations in operating systems by performing string substitutions upon a file paths or other resource identifiers to convert the virtual destination of an I/O operation to a physical destination. In accordance with the present invention, a virtual file system translation driver is interposed between a file system driver and applications and system utilities. The virtual file system translation driver receives file access requests from the applications and system utilities, and translates the file path to virtualize the file system. In a first embodiment, the file system is partially virtualized and a user can see both the virtual file paths and the physical file paths. In second and third embodiments, the file system is completely virtualized from the point of view of the applications and system utilities.

Abstract: A method and apparatus virtualizes file access operations and other I/O operations in operating systems by performing string substitutions upon a file paths or other resource identifiers to convert the virtual destination of an I/O operation to a physical destination. In accordance with the present invention, a virtual file system translation driver is interposed between a file system driver and applications and system utilities. The virtual file system translation driver receives file access requests from the applications and system utilities, and translates the file path to virtualize the file system. In a first embodiment, the file system is partially virtualized and a user can see both the virtual file paths and the physical file paths. In second and third embodiments, the file system is completely virtualized from the point of view of the applications and system utilities.

Abstract: A dynamic trace-driven object code optimizer provides for dynamic, real-time optimization of executable object code. The dynamic trace-driven object code optimizer bases the real-time optimization of executable object code on data gathered from execution traces collected in real-time. The executable code is then modified in real-time to generate optimized object code that is able to run more quickly and efficiently on the current system.