FireSim is an open-source, FPGA-accelerated hardware simulation platform designed to provide cycle-accurate, full-system simulations of hardware designs at speeds ranging from tens to hundreds of megahertz. Developed by the Berkeley Architecture Research Group at the University of California, Berkeley, FireSim enables users to validate, profile, and debug Register-Transfer Level hardware implementations efficiently. It supports simulations from single System-on-Chip designs on on-premises FPGAs to large-scale datacenter simulations utilizing numerous cloud-based FPGAs. Key Features and Functionality: - Scalability: FireSim can simulate configurations ranging from individual SoCs to extensive datacenter-scale systems comprising thousands of multi-core compute nodes. - Flexibility: The platform supports various FPGA platforms, including AWS EC2 F1 instances and Xilinx Alveo boards, offering both on-premises and cloud deployment options. - Comprehensive Modeling: FireSim includes validated hardware and software models for components such as DRAM, Ethernet, disks, and UART, facilitating the creation of closed and deterministic simulation environments. - Open-Source and Community-Driven: The platform is open-source, encouraging contributions from a global community of developers and researchers. Primary Value and Problem Solving: FireSim addresses the need for high-performance, accurate hardware simulations without the substantial capital expenditures traditionally associated with large-scale FPGA-based simulations. By leveraging cloud resources, it offers elasticity and cost-effectiveness, enabling researchers and developers to conduct extensive hardware-software co-design and validation processes efficiently. This capability is particularly beneficial for datacenter architecture research and the parallel execution of numerous single-node architectural experiments.