Extended T-Kernel — RTOS for embedded systems

eSOL has improved and fine-tuned T-Kernel, the T-Engine standard real-time operating system (RTOS). The result is eT-Kernel, a RTOS for embedded systems.

eT-Kernel/Compact is a core of all three profiles of eT-Kernel RTOS. The RTOS has been certified for the following functional safety standards;
・ISO 26262 Automotive Safety Integrity Level D (ASIL D)
・IEC 61508 Safety Integrity Level 4 (SIL 4)

eT-Kernel Platform Safety Package
eSOL provides eT-Kernel Platform Safety Package, which consists of safety reports and safety manuals, for users to conform to functional safety standards. The lineup of eT-Kernel Platform Safety Package is as follows;

  • Automotive Safety Package (ISO 26262-compliant)
  • Industrial Safety Package (IEC 61508-compliant)
  • Medical Safety Package (IEC 62304-compliant)
    *Expected to be launched in 2015

Features and benefits

Improved and tuned open source T-Kernel

Based on the T-Kernel source code distributed by the TRON Forum, eSOL has applied extensive experience gained through µITRON to improve and fine-tune both functionality and performance. eT-Kernel has the following features compared to the open source T-Kernel:

  • Dramatically shortened system startup time
  • Improved interrupt response time
  • Service calls for task switching, activation, and finalization are faster
  • Functions added to adjust memory footprint by configuration
  • Improved portability by layering and modularizing the hardware dependent code

Maintains compatibility with T-Kernel

eT-Kernel maintains full compatibility with the T-Kernel distributed by the TRON Forum. eSOL is a registered distributor of modified versions certified by the TRON Forum.

Available in three profiles

eT-Kernel is Available in three profiles to fit any system size and purpose. From a compact model with high real-time performance similar to µITRON to a model with memory protection and a process model like Linux, and to a model which is compliant with POSIX specifications, eSOL has it covered.

RTOS compliant with POSIX specifications

RTOS with memory protection and a process model for large systems

Compact RTOS with high real-time performance. Configuration is similar to µITRON

Software assets can be reused on the three profiles

eT-Kernel/POSIX, eT-Kernel/Extended, and eT-Kernel/Compact have the same core kernel. Therefore, device drivers and middleware can be reused on each profile as kernel applications. Reusing software can improve development efficiency especially when changing profiles based upon a product series.

Common development environment for three profiles: eBinder

eSOL offers eBinder, a development environment for T-Kernel-based embedded software development. eBinder can be used for development with everything from the µITRON-based PrKERNELv4 to T-Kernel/Compact, eT-Kernel/Extended, and eT-Kernel/POSIX. There is no need to learn a new development tool every time the OS or target profile changes.

Easy migration from PrKERNELv4

Migration from PrKENRELv4 is easy because the hardware-dependent code is shared between eT-Kernel and PrKERNELv4.


All three profiles of eT-Kernel are available in source code.


A full line of documentation including User's Guide, Board Support Guide, and Getting Started are available.

Maintenance service and customization service

The following maintenance service is offered for eT-Kernel:

  • Email response regarding the product
  • Minor version upgrades
eSOL also offers customization service to tailor eT-Kernel to a different environment, such as custom hardware.

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T-Engine's configurable software architecture

T-Engine has a scalable layered software architecture that is configurable depending on the system being developed. T-Kernel is the core of the architecture with various appendable schemes to encourage the reuse of software. The following shows the features and benefits of each architectural component.


T-Kernel consists of: The T-Kernel/Operating System (T-Kernel/OS), the T-Kernel/System Manager (T-Kernel/SM), and T-Kernel/Debugger Support (T-Kernel/DS). The list below shows their functions. T-Kernel/OS is the main part of T-Kernel and includes all task management features, memory management features, and system control features included in a standard realtime OS such as µITRON. T-Kernel/OS can only be called T-Kernel in a strict sense.

(Operating System)
(System Manager)
(Debugger Support)
  • Task control
  • Task synchronization and communication
  • Memory management
  • Exception/interrupt control
  • Time management
  • Subsystem management
  • System memory management
  • Address space management
  • Device management
  • Interrupt management
  • I/O port access support
  • Power management
  • System configuration information management
  • Kernel internal status referencing
  • Execution trace

Device drivers

T-Engine defines a standard driver interface and device driver specification. This is applied to device drivers for all peripherals loaded on a standard T-Engine board. Standardizing the driver interface makes middleware portable from one hardware environment to another.


A subsystem is a shared library with an interface defined by T-Engine. As indicated in the diagram, a subsystem operates on T-Kernel, while T-Kernel/OS controls the subsystem within T-Kernel. It can be linked to T-Kernel statically or loaded dynamically. For example, middleware like a file system or TCP/IP protocol stack can be implemented as a subsystem. A user library can also be implemented as a subsystem. Implementing middleware or a library created by a user as a subsystem provides a common interface to upper layer applications. Because a subsystem is not dependent on a CPU or board, even when hardware is changed, a subsystem does not need to be modified; only recompiling is required to migrate to a new platform.

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