Abstract

Traditional approaches to NIC driver design focus on commodity network hardware, which exhibit slow moving feature sets and long product life cycles. The introduction of FPGA based network adapters alters the status-quo considerably. Whereas traditional ASIC based NICs may undergo minor driver interface revisions over a timespan of years, FPGA based NIC interfaces can be totally reimplemented in months or even weeks. To the driver developer this presents a considerable challenge: Driver development cannot seriously begin without hardware support, but is now expected to take place simultaneously with hardware development. To solve this problem, I present the userspace, virtual NIC framework (uvNIC). uvNIC implements a custom virtual NIC as a standard userspace application. To the driver developer, it presents a functional equivalent to a physical device. Only minor modifications are required to switch a uvNIC enabled driver over to operating on real hardware. To the hardware designer, uvNIC presents a rapid prototyping environment for initial specifications and a fully functional model against which HDL code can later be verified.