COFILOS MCF52233-FunkOS

Flash compilation of same project.

More organized final version
SysTick now uses SWI for CSW as this is now async.
Tasks are split on different files
Fixed macros for fast stack check
Cleaned up some port code.

Made Stack check to check long-words (to avoid coincidential 0xFF).
Not as accurate as initial stack check but very fast compare to it.

Changed PE CPU frequency to 50MHz (was 40MHz). Now timings work right as in
Flash config.

Systick without stack check is 14uS.
Systick with stack check is 22.6uS.
CPU at 50MHz.

Added Programmable Flash/RAM configuration
Now code runs from RAM for faster developement

SysTick performs context save/restore on end-points.
It does not use the Yield command.

Yield command made to work through Software interrupt.
It uses an unused IRQ on INTCL0 (16) through forcing.
As this level is the lowest possible, then Yield from an IRQ will wait
till IRQ exists before making the CSW. Thus Yield is now async.

Trap mechanism was Synchronous (executed immediately).
Both methods worked.

Stack checking does a binary search thus making execution time with stack check
from 110uS to 45uS.
Systick execution is around 30uS. Thus the stack check penalty is 15us.

Added Led2 for measuring context switch time.
On MCF52233 @ 50MHz Core clock we have from from 25-64-105us (min-mean-max).
Stack investigation on idle task shows that nothing is wrong.
Idle task has 60 bytes free limit from its maximum.
Trap vectors removed from PE CPU.
Need to check the SysTick IRQ and at least remove any uncessary subsequent calls
to reduce stack usage.

Added semaphore for testing.
Footprint for this config is 9K flash and 976 bytes RAM.

Some modifications on Stack size and handling (init)
Now stack is ULONG instead of USHORT.
Checked issue with margin on idle task but everything seems fine.
Added a current stack size for easier on the spot debugging.

First Working Port!!!

Port to my main PC.
Working with context switches.
Reverted to fully ASM.
Seems stack is underflow?
Need to check frequency of SysTick.

first context switch works.
As the scheduler is now enabled,
a format exception occurs during the OS context switches.

Started working on porting.
Save/Restore Context using Trap # exceptions
Next: First context switch