As embedded systems get more complicated, the need to combine workloads, especially those that involve both real-time and general-purpose tasks, has grown a lot. Virtualization is a great solution because it lets multiple operating systems or applications run safely and quickly on the same piece of hardware. Jailhouse is one of the many hypervisors made for these kinds of situations, and it stands out because of its simple, real-time-focused design.
The i.MX and Layerscape series of ARM-based processors from NXP are used a lot in automotive, industrial, and IoT applications where safety and performance are very important. Developers can use multi-core processing capabilities with NXP CPUs and the Jailhouse hypervisor. This makes sure that real-time tasks stay predictable and don’t get affected by non-critical workloads.
What Is Jailhouse?
Jailhouse is a free, Linux-based partitioning hypervisor that lets you make separate domains, or “cells,” on one processor. Jailhouse uses asymmetric multiprocessing (AMP) instead of full virtualization or emulation. The Linux kernel takes care of starting up the system and managing its hardware. When Jailhouse is turned on, it takes over the hardware and divides up resources like CPUs and devices among different cells. This method makes sure that real-time applications (RTOSs) can run with little interference from the Linux environment.
Why Choose Jailhouse Over Other Hypervisors?
When evaluating hypervisors for embedded or real-time systems—such as those running on NXP CPUs—key factors include determinism, simplicity, performance, security, and hardware control. Here’s how Jailhouse stands out:
- Root Cell: The primary Linux environment that manages the system’s resources.
- Inmate Cells: Isolated environments running real-time operating systems or bare-metal applications
- Memory Reservation: Specific regions of memory are reserved for the hypervisor and inmate cells, ensuring that these resources are not accessed by the Linux kernel
Boot Workflow:
- Boot into Linux
- System starts with a standard Linux kernel.
- Linux initializes all hardware.
- Load Jailhouse Module
- Jailhouse is loaded as a kernel module.
- It takes control of hardware virtualization features (e.g., ARM EL2).
- Linux Becomes Root Cell
- Linux continues running in the “root cell” (housekeeping cell).
- Handles non-critical tasks and system management.
- Create Non-Root Cells (“Inmates”)
- Jailhouse partitions resources (CPU cores, memory, devices) for isolated guest domains.
- Each cell is strictly separated—no resource sharing unless explicitly allowed.
- Run Guests (OS or Bare-Metal)
- Guest systems (real-time OSes, RT-Linux, or bare-metal code) run directly on assigned hardware.
- No hypervisor intervention at runtime → near-zero overhead.
- Boot into Linux
Key Areas of Use for Jailhouse Hypervisor
- Automotive Systems
- Use cases: ECU consolidation, Advanced Driver
- Assistance Systems (ADAS), digital
- cockpits
- Why Jailhouse?: Enables real-time OS for safety-critical functions (e.g., braking) alongside Linux for infotainment or networking
- Industrial Automation
- Use cases: PLCs (Programmable Logic Controllers), robotics, factory controllers
- Why Jailhouse?: Isolates real-time control logic from user interfaces or monitoring systems
Aerospace and Defense
- Use cases: Flight control systems, mission-critical software
- Why Jailhouse?: Minimal codebase and deterministic behavior support certification
4. Medical Devices
- Use cases: Patient monitoring, imaging systems, surgical robots
- Why Jailhouse?: Separates user interface software from critical control software, aiding compliance
5. Telecommunications
- Use cases: 5G base stations, network function virtualization (NFV)
- Why Jailhouse?: Allows real-time packet processing on dedicated cores without interference from Linux processes
6. IoT Gateways and Edge Devices
- Use cases: Secure edge computing, real-time sensor data processing
- Why Jailhouse?: Isolates cloud-connectivity tasks from local real-time analytics or control
7. Research and Education
- Use cases: Teaching system architecture, experimenting with virtualization and security
- Why Jailhouse?: Open source, easy to understand, and highly customizable
Jailhouse Integration on iWave NXP SoM Platforms
- i.MX 8M Mini: Features ARM Cortex-A53 and Cortex-M4 cores, suitable for audio, voice, and video applications.
- i.MX 8M Nano: Equipped with ARM Cortex-A53 and Cortex-M7 cores, designed for cost-sensitive applications.
- i.MX 8M Plus: Includes ARM Cortex-A53 cores with added machine learning capabilities, ideal for industrial IoT and multimedia.
- i.MX 8M Quad: Offers ARM Cortex-A53 cores with enhanced performance for demanding applications.
- i.MX 8M QuadPlus: Provides additional GPU and VPU resources for high-performance multimedia tasks.
- i.MX 8QuadMax: High-end SoC with multiple ARM Cortex-A53 cores and advanced multimedia processing.
- i.MX 93: Features ARM Cortex-A55 cores, focusing on power efficiency and machine learning acceleration.
- i.MX 95: A safety-enabled platform with eIQ Neutron NPU, designed for high-performance applications.
For real-time and safety-critical applications, the Jailhouse hypervisor’s integration with NXP’s high-performance processors, like the i.MX 8 and i.MX 9 series, allows for effective, deterministic isolation.
By partitioning workloads without the complexity and overhead of full virtualization, Jailhouse provides:
- Hard real-time capabilities on specific cores
- Minimal footprint of the hypervisor
- Tight isolation for systems with mixed criticalities
- Support for bare-metal or Linux + RTOS combos
This makes it the perfect choice for edge computing, industrial, automotive, and medical applications that demand high performance and dependability.
iWave, an embedded systems engineering and solutions company, specializes in the design and manufacturing of embedded systems for the industrial, medical, and automotive vertical markets. iWave supports a wide portfolio of System on Modules, Single Board Computers and ODM Solutions such as telematics units, gateways, and HMI Solutions
For more information feel free to contact mktg@iwave-global.com or visit www.iwave-global.com.
