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  • T-Kernel/ITRON

    Ken Sakamura

    Professor at the University of Tokyo

    Chair of T-Engine Forum

    1Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • What is ITRON/T-Kernel?

    2Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Embedded Systems

    Computers are not just PCs Embedded systems

    Software systems embedded inside consumer electronics,

    automobiles, sensors/actuators, , etc.

    In fact, 98% of computing devices are embedded systems

    By 2020, over 40 billion embedded processors are predicted to be

    sold annually [ARTEMIS Joint Undertaking (EU)]

    3Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • What is Real-Time?

    (Hard) Real-Time Computer must process the given jobs within a specific amount

    of time (referred to as deadline)

    PCs are NOT hard real-time systems Users can wait until to disappear for practically indefinite

    amount of time

    Embedded systems ARE real-time systems E.g., Automobile must cause its brakes to work immediately

    The time MUST be assured to be upper-bounded; otherwise,

    Same for other embedded systems

    Because embedded systems interact with physical environments

    4Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Real-Time OS

    Real-Time Operating System (RTOS) Operating system with real-time assurance

    Multi-task (multi-thread) model

    Simplifies programming of operation workflows

    Task switching with real-time assurance

    5Copyright 2014 by T-Engine Forum., All Rights Reserved.

    Response time not bounded

  • Real-Time OS

    Is RTOS really needed? Is it practical for application programmers to write application

    codes to assume real-time behavior on multiple tasks by hand?

    Apparently too complex to handle The use of event-driven OS is thus limited to extremely-

    constrained devices & simple application scenarios

    6Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Real-Time OSThen, why not Linux or Android?

    Too heavy to ensure hard real-time, even when real-time

    scheduler is selected

    Lets compare the boot sequence

    7Copyright 2014 by T-Engine Forum., All Rights Reserved.

    Linux (typically boots with 10 secs) T-Kernel 2.0 + T2EX (boots instantly)

  • TRON Project

    TRON Project Started in 1984 to build an ideal computer architecture

    The vision we pursue has been HFDS (highly functional

    distributed system)

    a.k.a. IoT (Internet of Things), Ubiquitous Computing, M2M,

    One of the most important contributions is the

    standard embedded real-time OS (RTOS)

    ITRON (Industrial TRON) family (1987)

    T-Kernel family (2002)

    8Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • ITRON

    ITRON Features Real-time operating system

    TRON sub-framework for embedded devices

    Open architecture

    Specification made publicly available without any fee

    Chip Agnostic

    Not restricted to a specific hardware nor chip

    Efficient

    Equipped with abundant synchronization/communication API

    No virtualization, no processes

    Optimization

    Allows chip-dependent optimizations

    Relaxed specifications of chip-dependant functions (like interrupts)

    9Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • The Birth of T-Kernel

    Evolution of OS never ends As long as the computer evolves

    e.g. 64-bit address space space-efficient page tables

    e.g. higher clock frequency low-power (clock/power-gating, etc.)

    e.g. multi-core, virtualization

    Embedded technology advanced a lot since ITRON in 1987

    T-Kernel is the ITRON for the 21st century Based on the ITRON, industrial-proven for long since 1980s

    But with major revision to be adopted for computing technology

    of the 21st century

    10Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • T-Kernel

    Additional T-Kernel Features Open source

    The source code for T-Kernel is distributed for free

    Anyone can use it, alter them, and sell them

    Higher compatibility

    Achieved by the reference source code

    The original source code defines the specification, with no

    ambiguity

    Middleware and applications made reusable

    High compatibility makes software no longer strongly tied to

    specific board or chip

    Minimize the cost to develop richer embedded application systems

    11Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Acceptance of ITRON/T-Kernel

    ITRON/T-Kernel as a de facto standard Due to the successful concept and cooperation, ITRON/T-

    Kernel is now one of the de facto standards in the world RTOS

    According to a survey, ITRON/T-Kernel has had the topmost

    share for 18 consecutive years

    12Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • TRON Ecosystem

    13Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Maturity of ITRON/T-Kernel

    14Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Maturity

    ITRON/T-Kernel is a mature technology, having

    almost 30 years of industrial experience

    Thus accepted by mission critical applications Artificial satellites, spacecrafts,

    15Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Space Ships

    Hayabusa Launched in May 2013, and returned to the Earth in June 2010

    Has continued to work for 7 years in space

    Space Ship Hayabusa CPU: SH-3(SH7708) with triple redundancy

    OS: ITRON

    Space Probe MINERVA CPU: SH-3 (SH7708)

    OS: ITRON

    Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Artificial Satellites

    Space Ship Akatsuki and Solar Power Sail IKAROS Launched in May 2010

    Controlled by T-Kernel Camera control for Venus

    atmosphere observation

    Expansion and control of solar sail

    Processing photographs

    Space Telescope Hisaki (SPRINT-A) Launched in September 2013

    Controlled by T-Kernel

    17Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Proven Performance

    T-Kernel performance proved to perform the best

    in IEEE-authorized, third-party paper In both context-switching and interrupt-handling

    18Copyright 2014 by T-Engine Forum., All Rights Reserved.

    Source: T.Nguyen, B. Anh, S. Tan: Real-time operating systems for small microcontrollers,

    IEEE Micro Sept./Oct. 2009, pp-30-45

  • Evolution of ITRON/T-Kernel

    19Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Evolving T-KernelAgain, evolution of OS never ends

    As long as the computer evolves

    T-Kernel has continued to evolve to meet the

    demands of the era T-Kernel Standard Extension

    T-Kernel

    MP T-Kernel (SMP/AMP)

    T-Kernel 2.0

    T-Kernel 2.0 Extension (T2EX)

    T-Kernel 2.0

    20Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Evolving T-Kernel

    T-Kernel Standard Extension Extension to add PC-like rich OS functionalities to RTOS

    File systems, processes, standard I/O,

    Accepted in informational devices

    Car navigation systems,

    T-Kernel Compacted version of T-Kernel

    Can be used with 8KB ROM and 4KB RAM

    Suitable for 16-bit/32-bit processors with less ROM/RAM

    21Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Evolving T-Kernel

    MP T-Kernel Multi-processor and Multi-core support for T-Kernel

    Support for two models: AMP and SMP

    AMP (Asymmetric multi-processing)

    Each OS instance for each processors/cores Suitable for I/O-intensive applications,

    especially when tasks works with little dependencies

    SMP (Symmetric multi-processing)

    One OS instance works on multi-processors No need to define which task on which CPU Suitable for CPU-intensive applications Tend to lose real-time behavior by locks for resource protection

    22Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Evolving T-Kernel

    T1 to T2 After 10 years of T-Kernel, embedded computer systems have

    drastically changed

    At the same time, network, communication, and server-side

    technologies have evolved

    e.g., IPv6, WPAN, Cloud Computing,

    23Copyright 2014 by T-Engine Forum., All Rights Reserved.

    Now is the time for major update of T-Kernel:

    T-Kernel 2.0 (T2) the new RTOS for the age of IoT(Internet of Things)

  • Evolving T-Kernel 2.0

    T-Kernel 2.0 Major update of T-Kernel for the next decades

    Real-time support beyond RTOS

    Microsecond API (e.g., tk_dly_tsk_u)

    Physical-timer functions

    Fast locks (FastLock, FastMLock, )

    Microwaits (WaitUsec, WaitNsec, )

    Support for large-capacity devices

    Embedded systems now handles large-capacity disks

    e.g. Digital camera with MicroSD card > 4GB

    24Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Evolving T-Kernel 2.0

    Is Microsecond API really needed? Not always, but YES

    e.g. engines and motors

    When they rotate with 6,000 times per minute (6,000rpm), they

    rotate 36 degrees in 1 millisecond

    e.g. network communications

    Inter-frame gap of Ethernet (10Mbps): 9.6s

    Initial retransmit time of data-link layer protocols

    (incresed by exponential backoff): 10s200s

    25Copyright 2014 by T-Engine Forum., All Rights Reserved.

  • Evolving T-Kernel

    T-Kernel 2.0 Extension (T2EX) RTOS Extension w

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