Showing papers on "Legacy mode published in 2004"

Switching between multiple software entities using different operating modes of a processor in a computer system

Abstract: A processor has multiple operating modes, such as the long/compatibility mode, the long/64-bit mode and the legacy modes of the x86-64 microprocessor. Different software entities execute in different ones of these operating modes. A switching routine is implemented to switch from one operating mode to another and to transfer control from one software entity to another. The software entities may be, for example, a host operating system and a virtual machine monitor. Thus, for example, a virtual computer system may comprise a 64-bit host operating system and a 32-bit virtual machine monitor, executing on an x86-64 microprocessor in long mode and legacy mode, respectively, with the virtual machine monitor supporting an x86 virtual machine. The switching routine may be implemented partially or completely in an identity-mapped memory page. Execution of the switching routine may be initiated by a driver that is installed in the host operating system of a virtual computer system.

System and method for deploying new equipment and services in conjunction with a legacy provisioning system

Abstract: In one embodiment, a new device or service can be treated as an abstraction, allowing a model to be created which mimics operation of the device or service, but which does not physically exist. A communication system may then take physical assets that are distributed around a network, such as circuit packs with ports on them, and virtually plug them into a shelf that does not physically exist. A legacy system preferably continues to function as it always has and the abstraction mediates between the legacy operations support systems, the virtual machine and the physical reality. This then allows for the continued use of existing operation systems to manage new network architectures with services different from those originally contemplated by the legacy operations support systems.

Emulating a host architecture in guest firmware

Abstract: Systems and methods provide for emulating a host architecture in guest firmware. One aspect of the systems and methods comprises determining whether an emulated instruction would cause a transition into a legacy mode. A current execution context is converted into a legacy mode context, and the firmware emulator proceeds to a group of legacy mode instructions in a native mode for the processor. The firmware emulator detects an end instruction and converts the legacy context back to the guest firmware context.