Bringing Source-Level Debugging Frameworks to Hardware Generators

TL;DR

This paper introduces a framework that integrates source-level debugging tools with hardware generators, enabling easier debugging of generated RTL code within familiar IDE environments, with minimal performance overhead.

Contribution

It presents a novel framework that connects software source-level debugging to hardware RTL generated from high-level hardware description languages.

Findings

Supports breakpoints and variable inspection in generated RTL

Enables forward and backward debugging with less than 5% overhead

Provides IDE-like debugging experience for hardware generators

Abstract

High-level hardware generators have significantly increased the productivity of design engineers. They use software engineering constructs to reduce the repetition required to express complex designs and enable more composability. However, these benefits are undermined by a lack of debugging infrastructure, requiring hardware designers to debug generated, usually incomprehensible, RTL code. This paper describes a framework that connects modern software source-level debugging frameworks to RTL created from hardware generators. Our working prototype offers an Integrated Development Environment (IDE) experience for generators such as RocketChip (Chisel), allowing designers to set breakpoints in complex source code, relate RTL simulation state back to source-level variables, and do forward and backward debugging, with almost no simulation overhead (less than 5%).