APPARATUS AND METHOD FOR PERFORMING INTEGRITY CHECKS ON SOFTWARE

摘要

An apparatus and method are provided for performing integrity checking of software code executing on a processing unit of the apparatus. The apparatus further includes debug logic used when debugging program code executed by the processing unit, and trusted logic for performing trusted integrity checking operations on less- trusted program code executed by the processing unit. The debug logic has an interface via which the trusted logic can program one or more control registers that interface not being accessible by the less-trusted program code. The trusted logic programs the control registers so as to cause the debug logic to be re-used to detect one or more activities of the processing logic during execution of the less-trusted program code, and the trusted integrity checking operations performed by the trusted logic are influenced by the activities detected by the debug logic. Such an approach has been found to provide an efficient and secure technique for performing run-time integrity checking of program code.