KRNL - An Arduino Kernel - Usage and Configuration and Install
Just install krnl.zip in you arduino IDE
Optimization
Two important things to optimize for:
ram usage
cpu usage
Different Arduinos has from 512B up to 8 kB or RAM.
KRNL use of RAM is static and is set by call to k_init
You have to give max number of tasks, semaphores and message queues as parameters to k_init
IF you try to create more tasks, semaphores or message queues than the limit you have given by k_init SNOT will NOT start when you are calling k_start !!!
Stack
There shall be space for at least a context swicth on the stack which is approx 35 B on top of your use of local variabels in functions.
KRNL call k_stak_usage can write og Serial stack status (unused stack) for your tasks. To be able to write you have to define STAK_USAGE in krnl.h
k_unused_stak returns as name indicate unused stack for a task
rest has to be corrected /JDN
maybe not all up to date
A test setup
4 tasks
3 semaphores
2 message queues
gives (432)*15 + 2*12 + 34 = 193B plus stak for the tasks
100B for each task gives 193 + 400B = 600B of RAM usage.
happy krnl hacking
As long as you retain this notice you can do whatever you want with this stuff on these pages.
If we meet some day, and you think this stuff is worth it, you can buy me a beer in return :-)
(C) Jens Dalsgaard Nielsen
credit for license this goes to phk@FreeBSD.ORG
