Hewlett-packard Company

Idea Corporation

Cary Coutant

Jonathan Kent Ross

Achmed Rumi Zahir

William B Buzbee

Prasad A Raje

Sunil Saxena

Anthony Fitzgerald Istvan

Carol Thompson

The inventive mechanism allows an application to switch modes during its operation, between a compatibility or legacy mode for a previous architecture, and a native mode for a current architecture. The mechanism includes an official function descriptor which describes information for accessing a function which resides in one module. The OFD has a legacy portion is useable by a legacy module and a native portion is useable by a native module. The mechanism also includes a linkage table that resides in a second module which references the function in the first module. The portion of the OFD which corresponds to the mode of the linkage table module is copied into the linkage table. Each portion contains one entry that corresponds to an address location of the function, and another entry that is a value for a register which refers to the data segment corresponding to the load module containing the function. The information in the OFD depends on whether the function is a legacy function or a native function.

Method and apparatus for the inter-operation of differing architectural and run time conventions

A computer-implemented method of switching contexts in a processor is provided. The processor includes a register stack (RS) that has first and second portions. The processor includes a register stack engine (RSE) to exchange information, in one of instruction execution dependent and independent modes between the second portion and the storage area. The computer implemented method of switching contexts includes the following steps: It is determined whether an interrupt occurred; a first register (IFM) configured to store a content of a second register (CFM) is invalidated, the CFM is configured to store control information related to the first portion; it is determined whether an interrupt handler needs to access the RS; and if so, the IFM is validated, the content of the CFM is copied to the IFM, and RSE is caused to exchange information between both the first and second portions of the RS and the storage area. On return from interruption, if IFM is validated, CFM is restored from IFM else CFM remains unchanged. The COVER instruction enables lightweight interrupt handling in a processor with a Register Stack.

Cover instruction and asynchronous backing store switch

Growing community of inventors

Saratoga, CA, United States of America

Cary Coutant