摘要:
A set of default registers of a processor are expanded into metadata registers on the processor of a computer system. The default registers having stored thereon data, while metadata which is related to the data is stored separately on the metadata registers.
摘要:
A set of default registers of a processor are expanded into metadata registers on the processor of a computer system. The default registers having stored thereon data, while metadata which is related to the data is stored separately on the metadata registers.
摘要:
An authenticated code module comprises a value that attests to the authenticity of the module. The value is encrypted with a key corresponding to a key of a computing device that is to execute the module.
摘要:
In some implementations, a processor may include a data structure, such as a translation lookaside buffer, that includes an entry containing first mapping information having a virtual address and a first context associated with a first thread. Control logic may receive a request for second mapping information having the virtual address and a second context associated with a second thread. The control logic may determine whether the second mapping information associated with the second context is equivalent to the first mapping information in the entry of the data structure. If the second mapping information is equivalent to the first mapping information, the control logic may associate the second thread with the first mapping information contained in the entry of the data structure to share the entry between the first thread and the second thread.
摘要:
A processor can be used to ensure that program code can only be used for a designed purpose and not exploited by malware. Embodiments of an illustrative processor can comprise logic operable to execute a program instruction and to distinguish whether the program instruction is a legitimate branch instruction or a non-legitimate branch instruction.
摘要:
Methods and apparatus for opportunistic improvement of Memory Mapped Input/Output (MMIO) request handling (e.g., based on target reporting of space requirements) are described. In one embodiment, logic in a processor may detect one or more bits in a message that is to be transmitted from an input/output (I/O) device. The one or more bits may indicate memory mapped I/O (MMIO) information corresponding to one or more attributes of the I/O device. Other embodiments are also disclosed.
摘要:
A processor with instructions to operate on different data types stored in a single logical register file. According to one aspect of the invention, a first set of instructions of a first instruction type operates on the contents of what at least logically appears to software as a single logical register file. The first set of instructions appears to access the single logical register file as a flat register file. In addition, a first instruction of a second instruction type operates on the logical register file. However, the first instruction appears to access the logical register file as a stack referenced register file. Furthermore, sometime between starting the execution of the first set of instructions and completing the execution of the first instruction, all tags in a set of tags indicating whether corresponding registers in the single logical register file are empty or non-empty are caused to indicate non-empty states.
摘要:
Method for producing a predetermined length page memory pointer record, according to a selected page size and a selected page address, the method including the procedures of: determining a dynamic location of a separator bit within the page memory pointer record, according to the selected page size and an initial page size, the initial page size being respective of the smallest page size in a given memory system, writing a predetermined value to the dynamic location, writing a sequence of values opposite to the predetermined value to selected page size bits of the page memory pointer record, when the selected page size is different than the initial page size, and writing the selected page address to selected page address bits of the page memory pointer record.
摘要:
A computer system includes an instruction prefetching mechanism that detects whether an instruction to be prefetched is located in a region of memory that is uncacheable. To perform an instruction prefetch, an instruction fetch unit (IFU) receives an instruction pointer indicating a memory location containing an instruction to be prefetched. The instruction pointer may be provided by a branch target buffer (BTB) as a result of a branch prediction, or by auxiliary branch prediction mechanisms, or actual execution. The IFU accesses an instruction translation look-aside buffer (ITLB) to determine both the physical address corresponding to the linear address of the instruction pointer and to determine an associated memory type stored therein. If the memory type indicates an uncacheable memory location, the IFU waits until all previous executed instructions have completed. The IFU does this by inserting a "permission-to-fetch" instruction, and then stalling. The IFU remains stalled until either the permission-to-fetch instruction retires or until a branch misprediction is detected. Once a branch misprediction is detected, the permission-to-fetch instruction and all other instructions issued subsequent to the mispredicted branch are squashed. If no previous branch mispredictions are detected, the permission-to-fetch instruction eventually retires, the instruction pointer is reset based on the correct branch, and prefetching continues.
摘要:
A system for detecting hazardous conditions during operation of a vehicle. In one embodiment, the system includes a plurality of sensors that monitor a plurality of conditions and transmit condition signals each representing a measure of a condition. A plurality of rate determination circuits is coupled to the sensors and continually receives the condition signals, wherein each rate determination circuit calculates rates of change for the condition, including a baseline rate of change, and outputs a potential hazard value representing a deviation of a rate of change from the baseline rate that exceeds a predetermined threshold value. An evaluation circuit receives the potential hazard value, calculates a new potential hazard value using the potential hazard value and a rate of change for at least one associated condition and determines whether an actual hazard exists by comparing the new potential hazard value with a stored value that corresponds to the condition.