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riscvOVPsim - Free Imperas RISC-V Instruction Set Simulator


riscvOVPsim - RISC-V Instruction Set Simulator (ISS) - fast, simple, easy to use, cross software development for embedded systems

The riscvOVPsim ISS is an ideal starting point for an embedded software development project.

riscvOVPsim allows the development and debug of code for the target RISC-V processor on an x86 host PC with the minimum of setup and effort. It simply requires the cross compilation of your application and running riscvOVPsim with an argument to specify the name of the application object.

It is FREE to download from

GitHub here: for FREE!

OVPworld here: for FREE! enhanced riscvOVPsim including the new test suite for RISC-V vector extensions


riscvOVPsim Overview

Used by application software engineers who need to create software binaries for RISC-V permitted configurations and variants, but who do not need platform components - riscvOVPsim works with a standard GDB debugger and GUI which makes it very easy to get started with full source code interactive debugging.

Middleware library developers can also use riscvOVPsim when building software libraries for common functions, for example multimedia standards where they code at the assembly level and make extensive use of the processor data path - the debugger/GUI shows detailed assembly and all processor registers.

Test engineers can use riscvOVPsim in a regression test environment as it can be used in batch/scripted environments as well as being used interactively.

riscvOVPsim is also used by the RISC-V Foundation's Compliance working group in the RISC-V compliance test suite and framework, the latest version is available on GitHub:

riscvOVPsim makes use of the Imperas OVP Fast Processor Model library for RISC-V single core instruction accurate configurations and variants.

Speeds of up to 1,000 MIPS can be expected on modern desktop PCs.

riscvOVPsim - detailed features

Released to run in x86 64 bit Windows/Linux environments.

  • includes a free to use simulation license from Imperas, which supports commercial as well as academic use. The RISC-V open source model is licensed under the Apache 2.0 license.
  • includes the full publicly released Imperas OVP Fast Processor Models of RISC-V which covers all the single core 32/64 bit RISC-V permitted configurations and variants.
  • includes a GDB debugger
  • configurable trace subsystem to provide instruction and register tracing
  • loads .elf file binaries directly
  • allows one instance of a single CPU with full memory construction
  • uses built in semi-hosting to support library functions such as printf and fopen, and can access host native resources
  • can be run interactively or in script/batch mode for regression testing
  • includes Imperas Just-In-Time (JIT) Code Morphing high performance CPU simulator technology
  • works with Eclipse/CDT GUI

Optional Upgrades to riscvOVPsim for multi-core RISC-V, custom instructions, heterogeneous processors and virtual platforms

Imperas produces a range of products that can be layered on the riscvOVPsim simulator:

Virtual Platform Development and Simulation solution (DEV) provides an extension to riscvOVPsim allowing the building of peripheral components and platforms to enable fast simulation of complete systems running Operating Systems (OS) and RTOS.

Multi-core Software Development Kit (M*SDK) provides the development of peripheral device models and virtual platforms using many heterogeneous or homogenous processors. M*SDK includes the Imperas Multi-Processor Debugger (MPD), and the very flexible Imperas Verification, Analysis, and Profiling (VAP) tools for embedded software development, debug and test.

Extendable Platform Kits (EPKs) are platforms built by Imperas that can be used out-of-the-box for software development. They include the CPU and main peripherals to enable full Operating Systems (OS) and RTOS to run. EPKs range from simple ones like the Atmel AT91SAM7 using an ARM7DTMI core and UART that boots ucLinux all the way to the ARMv8 Cortex-A57MPx4 Versatile Express that boots Linaro Linux. Many of the platforms include the Imperas virtualized UART, Ethernet, and USB models which not only run in simulation, but also connect to the real world allowing, for example a simulated browser to access the real internet, or the simulator to communicate with a real USB memory stick plugged into the host PC. For RISC-V there are EPKs and models of components from Microsemi, Andes, SiFive and others including the SiFive FU540 multicore platform that boots SMP Linux in under 10 seconds. To see this and others in action view the videos here.

QuantumLeap MPonMP (MultiProcessor target on MultiProcessor host) acceleration software which adds to the already industry leading performance of the ISS.  QuantumLeap accelerates simulation by taking advantage of the multiple x86/x64 cores on the host PC, which is especially advantageous for multi-core processors such as the ARM Cortex-A53MPx4, MIPS proAptiv or the SiFive RISC-V U540. QuantumLeap simulates in parallel what other tools can only do serially and in doing so is typically 6-15x faster than other commercial simulators. Used with the ISS, QuantumLeap provides parallel simulation of the single instance of the CPU cluster.

Download riscvOVPsim

riscvOVPsim is free, and available now for download on GitHub or with additional debug and trace features at It includes a free to use license from Imperas, which supports commercial as well as academic use. The RISC-V open source model is licensed under the Apache 2.0 license.

It is FREE to download from GitHub here: or OVPworld here: and includes additional trace and debug support.

Additional resources on riscvOVPsim and RISC-V solutions from Imperas

See the introduction to riscvOVPsim in this video

Additional RISC-V solutions can be found here