Virtual Devices for Hot-Pluggable Processors

When partially reconfigurable, FPGA-based, systems allow to dynamically hot-plug processors, the number of possible software configurations increases and the dynamic sharing of hardware peripherals becomes problematic. Moreover, the debugging of application processes, which needs physical devices to communicate with remote users or debuggers, is a critical service that becomes extremely difficult to implement. This work puts forward the concept of virtual devices to reduce software complexity and isolate system services from applications. It is illustrated by a methodology making the design of debug paths easier. Several experiments show that heterogeneous systems of up to 24 hot-pluggable processors can take advantage of virtual devices.