Virtual Hardware  Version 0.2 - beta
Product Overview
Introduction

Arm Virtual Hardware provides simulation models, software tooling, and infrastructure that can be integrated into CI/CD and MLOps development flows. Arm Virtual Hardware supports the software development cycle of embedded, IoT, and ML applications and provides essential components for effective test and validation environments. Arm Virtual Hardware is flexible and can run any RTOS that is designed for Cortex-M or bare metal code that interacts with the processor. Arm Virtual Hardware offers a comprehensive tool integration along with resources for software developers and can therefore run complex applications and software integration tests. A potential workload could be a sensor-fusion Machine Learning (ML) application that connects to the Internet via an IoT operating system.

Arm Virtual Hardware consists of the following components:

  • Arm Virtual Hardware Targets (VHT) are precise simulation models of Cortex-M device sub-systems and are designed for complex software verification and testing. It allows simulation-based test automation of various software workloads, including unit tests, integration tests, and fault injection.
  • Arm Virtual Hardware Services provide a cloud-native infra-structure for software test and validation. These Arm Virtual Hardware services can be integrated into various CI/CD and MLOps environments that range from GitHub to on-premise IT infrastructure. The Arm VHT services will be available via the AWS Marketplace (and later also via other Cloud Service providers).
  • Arm Virtual Hardware Developer Resources gives you access to interface drivers that map to virtual targets and physical hardware along with Python scripts for I/O simulation. The documentation explains how to integrate Arm VHT into typical CI/CD environments. Usage examples show typical usage cases and range from audio processing, ML algorithm testing, up to IoT applications that interface to Cloud Service providers.
  • Software Development Environments with Arm VHT integration are also available. Arm Virtual Hardware is an integral part of the Keil MDK Professional Edition that is a comprehensive software tool suite for creating Cortex-M-based applications and related validation and test processes. In future, the next-generation Keil Studio will also integrate Arm Virtual Hardware.
Arm Virtual Hardware - Components

Documentation Structure

Section Description
Overview Introduces Arm Virtual Hardware along with the top-level structure.
Simulation Explains the Arm Virtual Hardware Targets (VHT) along with the simulation technology and the virtual interfaces.
Infrastructure Describes how to setup development work flows with Arm Virtual Hardware.
Examples Guides you through the examples demonstrating how to use Arm Virtual Hardware.

User Benefits

Test without Hardware

Arm Virtual Hardware allows to verify your code without the need for physical hardware which provides a robust test environment that enables:

  • Early software development for faster time-to-market
  • Select optimal target device once the software workload is analysed
  • Re-target applications to production hardware with driver abstractions

Verify Correctness

Arm Virtual Hardware Targets are based on Arm simulation models that are validated with the same process as the IP. Specially it allows you to:

  • Algorithm testing with identical logical behaviour of the target device
  • Precisely repeat complex input patterns in CI/CD test environments
  • Analyse software behaviour with event annotations

Evaluate Performance

Software algorithms for Digital Signal Processing (DSP) or Machine Learning (ML) frequently require significant CPU resources and need to be optimized for the target hardware. Comparing performance of such "load heavy" algorithms requires that they can be automatically executed with different configurations parameters but using identical input.

Arm Virtual Hardware Services allows users to test their programs at scale with reproducible input patterns and so validate and optimize application performance which allows you to:

  • Compare speed of different implementations of an algorithm
  • Identify timing issues during system integration
  • Optimize resources (i.e. data buffers) towards application requirements

Continuous Testing

Applying continuous integration work flows for embedded applications can be complicated by the specifics of development environments and the need of executing the program on target hardware. So the development teams are often reluctant to spend initial effort setting up the continuous integration (CI) workflow even though the long-term benefits are undisputed as shown on the Figure below

Comparison of test efforts in CI and no CI workflows

Arm Virtual Hardware simplifies the setup and use of CI workflows in embedded projects.

For unit and integration tests virtual targets offer additional advantages over hardware, including:

  • Speed - no overhead for flashing the application on physical hardware. This saves time on small and fast unit tests.
  • Scale - virtual platforms can scale to run many tests in parallel. This makes virtual platforms more cost-effective than a farm of physical hardware.
  • Maintenance – unlike physical hardware, virtual platforms do not overheat, wear out from overuse, break from misuse, or use physical space and resources.
  • Upgrades – virtual platforms can be adapted and re-configured to match corresponding changes to the underlying hardware platform that is under development. These types of changes can be costly or impossible with physical hardware.

Product Roadmap

Arm Virtual Hardware is now in public beta phase. The table below shows features that we will deploy in the next 6 months. During the beta phase, you may evaluate how our products help in your development processes. The feature roadmap of Arm Virtual Hardware gives you indication what to expect. We will release this features as they become available during the beta phase to allow product evaluation before the final release.

Feature Description
VSocket Interface BSD socket interface that connects the application under test to networks, including public Internet.
VIO Interface Simple interface to control I/O such as switches and LEDs via Python scripts.
Support in MDK-Professional Desktop development will be enabled in classic tooling, with priority on MDK. This complements our CI Cloud service that is already deployed.
Extended Target support The Corstone-300 model is a Cortex-M55/Ethos-U55 simulation that allows to develop a wide range of applications. Support will be extended to many other Cortex-M processors.
Event Recorder CLI Tools Event Recorder is currently supported in MDK. This support will be extended to off-line and command line tools.
More Usage Examples Example projects help to get started: Audio/Video/Sensor I/O, Cloud connectivity, CI integration, Test code development is the range of examples we are working on.

Known Limitations

The current beta version of of Arm Virtual Hardware has the following known issues:

VSI Interface

  • With TrustZone enabled, the DMA of the Cortex-M55 processor does not work in Secure mode in the address ranges of the TCM aliases (0x10000000 ITCM and 0x3000000 DTCM).

Feedback and Support

The Arm Virtual Hardware is supported during public beta via this Arm forum. Your feedback will influence our future roadmap and we try to help you promptly with your questions.