Patent ID: 6530017
Filing Date: 2003-03-04
Classification: G06F

Abstract:
An operating system call control subsystem for use in a computer including a processor for processing a program, the program having at least one instruction of an operating system call instruction type, said instruction of the operating system call instruction type identifying one of a plurality of types of operating system calls, each type of operating system call being associable with an operating system call type identifier value within a predetermined range of values, the operating system call control subsystem comprising:A. a crossover table configured to have a number of entries corresponding to a predetermined fraction of the predetermined range, each entry in said crossover table having an instruction for enabling the processor to save a value corresponding to an offset of the entry into the crossover table, B. an operating system call instruction type address resolution module for providing the at least one instruction of the operating system call instruction type with a target address value that includes an operating system call set identifier in a set of operating system call set identifiers, the number of operating system call set identifiers multiplied by the number of crossover table entries corresponding to the predetermined range and an offset value corresponding to an offset to an entry into the crossover table, and C. an operating system call instruction type processing module configured to, in response to the processor processing the at least one instruction of the operating system call instruction type, (a) save the operating system call set identifier from the target address, (b) select one of the entries in the crossover table using the offset value of the target address, (c) process the instruction from the selected entry of the crossover table to save the value corresponding to the offset of the selected entry in the crossover table, and (d) generate the operating system call type identifier value associable with the operating system call in connection with the saved operating system call set identifier and the saved value corresponding to the offset of the selected entry in the crossover table.