Nucleus process model adds space domain partitioning for task and module isolation on SOCs with either a memory management unit (MMU) or memory protection unit (MPU), such as those based on ARMv7/8 Cortex-A/R/M cores.
Supported platforms
Nucleus supports many embedded processors including leading ARMv7 Cortex A, R, and M devices. Recent releases support ARMv8 64-bit devices. The official website has a full list of supported devices.[2] It includes 32-bit MCUs and MPUs, configurable devices, and 32-bit and 64-bit multi-core processors.
History
Nucleus 1.x was released first in 1993 by Accelerated Technology (ATI) as Nucleus PLUS. It soon became one of the most commonly used RTOSs in the embedded market. Following its early success there, ATI added support for networking, graphics, and file systems, which accelerated adoption.
Mentor Graphics acquired ATI in March 2002, which was soon followed by the second generation of Nucleus RTOS. Version 2.x was released in 2003, improving its portability across different architectures and tool sets. New components like IPv6, Flash memory file system and Universal Serial Bus (USB) 2.0 were added. Mentor replaced the legacy Codelab debugger with EDGE development tools which included compiler tools, debugger, simulator, and profiler.
Mentor Graphics introduced the 3rd generation Nucleus in 2010. Version 3.x was intended for both high-end microprocessor units (MPUs), microcontroller units (MCUs), digital signal processors (DSPs), and field-programmable gate arrays (FPGAs). For devices with limited memory resources, Nucleus was designed to scale down to a memory size of <10 kilobytes (KBs) for both code and data.
Integrated power management support for kernel and middleware components; includes support for DVFS, tick suppression, and sleep modes including hibernation.
Process model for memory partitioning to support dynamic loading and unloading of application modules. Loadable processes are supported on both high end MPUs and low end MCUs with or without hardware memory management support.
Wireless support
IoT protocols
Safety certification for aerospace, medical, industrial and automotive
Mentor embedded multi-core framework for IPC and processor life cycle management for AMP designs (both supervised sAMP and unsupervised uAMP)
Runtime tracing support with host side analysis tools
In addition to the new features in version 3.x, Nucleus moved business model from a la carte, to one unified package.
Mentor acquired CodeSourcery in Dec 2010 to replace the EDGE development tools with the Sourcery CodeBench. Sourcery CodeBench comprises a compiler tool-chain, debugger, and trace analysis tools. The compiler tool-chain is based on GNU tool-chain. The debugger and integrated development environment (IDE) are based on Eclipse. Sourcery CodeBench supports ARM, IA-32, MIPS, and PPC architectures with built-in workflows and OS awareness for Nucleus RTOS and Mentor Embedded Linux.
Nucleus 3.x introduced a unified build and configuration system with which the Kernel is configured through a single file and builds as a single library. Like menuconfig in Linux, a user interface (UI) based configuration tool integrated with CodeBench provides the user with graphically selectable components to customize the kernel at build time. The Nucleus configuration system allows for user customization to integrate new tool-chains, architecture support and build properties.
Unlike Windows and Unix-like operating systems, Nucleus does not need a file system to work. However, for complex uses needing local storage, Nucleus supports several file systems including FAT, SAFE (fault tolerant), and LWEXT.
Nucleus provides support for different file systems and storage media through a virtual file system application programming interface (API) that allows access to the supported file systems and storage devices using the same functions calls regardless of the underlying storage format.
Networking
The Nucleus networking stack is a dual IPv4 and IPv6 stack that supports over 60 networking protocols. Nucleus networking stack supports POSIX and provides an easy to use socket based application interface. A brief list of the supported protocols include:
Nucleus supports a wide variety of encryption options for secure communications to protect data at rest or in transit. Nucleus ships with OpenSSL and an OpenSSL-like package wolfSSL (formerly CyaSSL) that is far smaller than OpenSSL for designs needing encryption but limited in memory capacity.[3] Security protocols to protect data in transit include IPsec/IKE, SSH/SSL/TLS/DTLS. Encryption includes DES, 3DES, AES, SHA-256. Public-key cryptography algorithms include RSA. Support includes X.509, RADIUS, and 802.1X.
Wireless
Several Wi-Fi modules from different chip-makers like QCA, Broadcom, TI, and CSR are supported:
Nucleus 3.x supports OpenGL and leading 3rd party UI libraries. Nucleus supports the Qt UI framework which has been optimized for code size and integrated into CodeBench for debugging and tracing. Other UIs supported include Embedded Wizard and Socionext CGI Studio.
Nucleus supports asymmetric multiprocessing (AMP) mode and symmetric multiprocessing (SMP) mode for leading 32 and 64-bit heterogeneous multi-core SoCs. Nucleus is also capable of running as a GOS with Mentor Embedded Hypervisor.
When operating in AMP mode, Nucleus RTOS can coexist with other instances of Nucleus, Linux, and/or bare machine (metal) programs distributed on the other processors. In this mode, each processor is running independently and behaves as a separate system within the SoC. Mentor Embedded Multicore Framework provides interprocess communication between operating systems on the various cores, and processor life cycle management. SMP operation entails having a instantiation of Nucleus RTOS manage multiple cores simultaneously. Nucleus can distribute its operations across all cores on a multi-core device, or any subset of cores. For this purpose Nucleus offers runtime API support for bound computation domain, and control tasks and interrupt affinities for core assignment.
Product packages
Nucleus RTOS is packaged as follows:
Nucleus ReadyStart Edition ReadyStart which includes the runtime system, middleware, BSP (all in source code) and the IDE, debugger, compiling tools, trace bundle in a single package. Nucleus Ready Start comes in versions packaged for ARM, MIPS and PPC. Nucleus ReadyStart adds specialized eclipse plugins to CodeBench to provide simplified build and configuration workflows and debugging enhancements including kernel awareness, loadable module support, tracing and profiling tools.
Nucleus Source Code Edition contains the runtime system and middleware packaged to support unique architectures and/or different tool chains