TNKernel real-time kernel (version 2.6)


Introduction:
 TNKernel is a compact and very fast real-time kernel for the embedded 32/16 bits microprocessors.
 TNKernel performs a preemptive priority-based scheduling and a round-robin scheduling for the tasks with
identical priority.
 The current version of TNKernel includes semaphores, mutexes, data queues, event flags and fixed-sized
memory pools. The system functions calls in the interrupts are supported.
 TNKernel is a fully portable (written mostly in ANSI C except processor-specific parts).
 TNKernel has been written “under the significant influence” of the μITRON 4.0 Specifications.
 The μITRON 4.0 Specifications is an open real-time kernel specification developed by the ITRON
Committee of the TRON Association.The μITRON 4.0 Specification document can be obtained from
the ITRON Project web site (http://www.assoc.tron.org/eng/document.html).
 TNKernel is distributed in the source code form free of charge under the FreeBSD-like license.

 This is port for YRDKRX62N board. Board contains R5F562N8BDFP, member of Renesas RX600 microcontroller series.
Port was made for vanilla GCC v4.7.1, Binutils v2.22.52, NewLib v1.20.0.


Features & known limitations:
* OS tick timer ticks with 256 Hz frequency
  (RTC periodic interrupt is used for that purpose, if higher frequency is required - use MTU or CMT).
* Standard output is redirected to SCI2 with baud rate 115200 bps (printf and puts functions are thread safe and block execution till the end of transmission).
* Floating point coprocessor status register is not saved for every task. (Is this required at all?)
* Accumulator value is not saved for every task.
* "Find first set" function is implemented as a loop. Fixed execution time function may be better.


Useful literature:
* TNKernel (v.2.3 and later) real-time kernel user's manual.
* RX Family. User’s Manual: Software.
* RX62N Group, RX621 Group. User’s Manual: Hardware.
* RX Family C/C++ Compiler, Assembler, Optimizing Linkage Editor. Compiler Package User's Manual.


Links:
* http://www.tnkernel.com/
* http://am.renesas.com/RDKRX62N
* http://www.renesasrulz.com/community/demoboards/rdk62n
* http://www.rxmcu.com/


Copyright notice:

Copyright ©2004, 2011 Yuri Tiomkin

All rights reserved.

Permission to use, copy, modify, and distribute this software in source and binary
forms and its documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting documentation.

THIS SOFTWARE IS PROVIDED BY THE YURI TIOMKIN AND CONTRIBUTORS "AS IS" AND
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ARE DISCLAIMED. IN NO EVENT SHALL YURI TIOMKIN OR CONTRIBUTORS BE LIABLE
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OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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