Dynamic Software Reconfiguration Using System-Level Management

摘要

The development tool requirements outlined to support dynamic software reconfiguration are nontrivial. The facilities provided by the SMM kernel must match the capability and requirements of the development tools. Failure to maintain a valid database that reflects the current system environment can create an unsafe and unstable system. By its veryrnnature the SMM kernel needs to peek and poke at the entire memory system, and there is no mechanism to validate the changes to the operating system environment. Redundancy can be added by enforcing a discipline of hardware-to-software synchronization both prior to generating a configuration change and after effecting the change.rnSMM-based dynamic software reconfiguration has a primary benefit: the SMM kernel is transparent to application programs and the operating system. Due to this transparency, there is no overhead to the operating system or application programs. This method is inherently safe in that it is initiated as a non-maskable interrupt. Application programs and the operating system are frozen while the processor is in SMM. Because the SMRAM is not accessible when the processor is not in SMM mode, the operating system and application environment cannot corrupt the SMM kernel.