Extending programs with debug-related features, with application to hardware development

TL;DR

This paper introduces Program-hosted Directability (PhD), a flexible method for runtime debugging, monitoring, and profiling of reconfigurable hardware programs, overcoming the limitations of fixed hardware debugging features.

Contribution

The paper presents PhD, a novel language and embedded controller for runtime program directing in hardware, enhancing flexibility with minimal performance impact.

Findings

Enables runtime debugging and monitoring in FPGA programs

Low hardware utilization and performance overhead

Prototype implementation demonstrates practical viability

Abstract

The capacity and programmability of reconfigurable hardware such as FPGAs has improved steadily over the years, but they do not readily provide any mechanisms for monitoring or debugging running programs. Such mechanisms need to be written into the program itself. This is done using ad hoc methods and primitive tools when compared to CPU programming. This complicates the programming and debugging of reconfigurable hardware. We introduce Program-hosted Directability (PhD), the extension of programs to interpret direction commands at runtime to enable debugging, monitoring and profiling. Normally in hardware development such features are fixed at compile time. We present a language of directing commands, specify its semantics in terms of a simple controller that is embedded with programs, and implement a prototype for directing network programs running in hardware. We show that this approach affords significant flexibility with low impact on hardware utilisation and performance.