Our RTOSes called DSPnano for 16 bit processors and Unison for 32 bit processors offer complete explanations of how they should be used and 20 or so out of the box and running examples for each processor port. There is a number of Unison ports and one DSPnano port in the works. They offer a tiny tiny embedded Linux or POSIX compatible RTOS without GPL.
http://rowebots.com/products/unison
http://rowebots.com/products/dspnano
http://rowebots.com/Embedded_Processor_support/renesas_m16c_development
http://rowebots.com/Embedded_Processor_support/renesas_H8SX
http://rowebots.com/Embedded_Processor_support/renesas_R32
And the documentation is on line here:
http://rowebots.com/downloads/DSPnano_Tutorial_GuideE8sec.pdf
http://rowebots.com/downloads/DSPnano_Programmers_Guide_E1sec.pdf
http://rowebots.com/manpages/help_index.html
or
http://rowebots.com/downloads/Unison_Tutorial_GuideE5sec.pdf
http://rowebots.com/downloads/Unison_Programmers_Guide%20E3sec.pdf
Please contact us for any clarification of any items.
Kim