Method for detecting modified object code in an emulator

Abstract

A method of emulating the instructions of a target computer in the instructions of a host computer to operate the host computer in accordance with the target computer instructions, the target computer having the capability of modifying its own instructions and data during operation, includes the steps of storing the target instructions in a target memory segment, sequentially withdrawing the target instructions from the target memory segment and executing the target instructions in the host computer, constructing a template of the host instructions for each of the target instructions executed, storing each of the templates for reuse each time the corresponding target instruction is to be executed, limiting access to those target instructions in the target memory segment which have been stored in one of the templates to permit only read operations to be performed thereon, and detectng a target instruction which attempts a write operation on one of the target instructions which is in a stored template.

Dependencies are inferred from the claim text.