Abstract: A processor system is disclosed that integrates error correcting code (ECC) detection and correction hardware within an memory management circuit. ECC hardware circuitry provides detection, correction and generation of ECC data bits in conjunction with memory data read and writes. The disclosed methodology permits the detection and correction of soft single bit errors read from local memory in-line while using read modify write DMA circuit logic to correct local memory data. The disclosed methodology provides local memory data error detection and correction in a background memory scrub process without the need for additional in-line data logic.

Abstract: An apparatus and method for providing a sealed storage in a data processing device are provided. Processors of the data processing device may operate in a hardware isolation mode which allows a process to execute in an isolated environment on a processor and associated memory thereby being protected from access by other elements of the data processing device. In addition, a hardware controlled authentication and decryption mechanism is provided that is based on a hardware core key. These two features are tied together such that authentication occurs every time the isolation mode is entered. Based on the core key, which is only accessible from the hardware when in isolation mode, a chain of trust is generated by providing authentication keys for authenticating a next piece of software in the chain, in each piece of software that must be loaded, starting with the core key.

Abstract: An apparatus and method for providing key security in a secure processor are provided. With the apparatus and method, a two-tiered key security mechanism is provided. On a first tier, a decryption mechanism and a fixed size storage area for a core key are hard-wired into the chip design. It is this first tier that is common to all systems and customers utilizing the processor design. On a second tier, off-chip but within the system is a secondary security key storage device that stores all the keys that are required by the particular system architecture. The off-chip storage device is programmed with the necessary keys before the system is shipped to the customer and thus, provides the needed flexibility. For protection, the keys are stored as an encrypted image using the core key stored on-chip.

Abstract: An apparatus, method and computer program product are provided for using multiple thread contexts to improve processing performance of a single thread. When an exceptional instruction is encountered, the exceptional instruction and any predicted instructions are reloaded into a buffer of a first thread context. A state of the register file at the time of encountering the exceptional instruction is maintained in a register file of the first thread context. The instructions in the pipeline are executed speculatively using a second register file in a second thread context. During speculative execution, cache misses may cause loading of data to the cache may be performed. Results of the speculative execution are written to the second register file. When a stopping condition is met, contents of the first register file are copied to the second register file and the reloaded instructions are released to the execution pipeline.

Abstract: An apparatus, method and computer program product are provided for using multiple thread contexts to improve processing performance of a single thread. When an exceptional instruction is encountered, the exceptional instruction and any predicted instructions are reloaded into a buffer of a first thread context. A state of the register file at the time of encountering the exceptional instruction is maintained in a register file of the first thread context. The instructions in the pipeline are executed speculatively using a second register file in a second thread context. During speculative execution, cache misses may cause loading of data to the cache may be performed. Results of the speculative execution are written to the second register file. When a stopping condition is met, contents of the first register file are copied to the second register file and the reloaded instructions are released to the execution pipeline.

Abstract: A system and method for limiting the size of a local storage of a processor are provided. A facility is provided in association with a processor for setting a local storage size limit. This facility is a privileged facility and can only be accessed by the operating system running on a control processor in the multiprocessor system or the associated processor itself. The operating system sets the value stored in the local storage limit register when the operating system initializes a context switch in the processor. When the processor accesses the local storage using a request address, the local storage address corresponding to the request address is compared against the local storage limit size value in order to determine if the local storage address, or a modulo of the local storage address, is used to access the local storage.

Abstract: In a first aspect, a first method is provided that includes providing a plurality of select signals and a plurality of input signals for input by a multiplexer. Each select signal is adapted to cause the multiplexer to select a different one of the plurality of input signals for output by the multiplexer when the select signal is in a first logic state. The first method further includes preventing a first of the select signals that is in the first logic state from being provided to the multiplexer until the other select signals are in a second logic state. Numerous other aspects are provided.