As the unified kernel should replace the nanokernel and microkernel
lets go ahead and move code shared between the nanonkernel and unified
kernel into the unified kernel.
Change-Id: I8931efa5d67025381d5d0d9563e7c6632cece87f
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Summary of what this includes:
initialization:
Copy from nano_init.c, with the following changes:
- the main thread is the continuation of the init thread, but an idle
thread is created as well
- _main() initializes threads in groups and starts the EXE group
- the ready queues are initialized
- the main thread is marked as non-essential once the system init is
done
- a weak main() symbol is provided if the application does not provide a
main() function
scheduler:
Not an exhaustive list, but basically provide primitives for:
- adding/removing a thread to/from a wait queue
- adding/removing a thread to/from the ready queue
- marking thread as ready
- locking/unlocking the scheduler
- instead of locking interrupts
- getting/setting thread priority
- checking what state (coop/preempt) a thread is currenlty running in
- rescheduling threads
- finding what thread is the next to run
- yielding/sleeping/aborting sleep
- finding the current thread
threads:
- Add operationns on threads, such as creating and starting them.
standardized handling of kernel object return codes:
- Kernel objects now cause _Swap() to return the following values:
0 => operation successful
-EAGAIN => operation timed out
-Exxxxx => operation failed for another reason
- The thread's swap_data field can be used to return any additional
information required to complete the operation, such as the actual
result of a successful operation.
timeouts:
- same as nano timeouts, renamed to simply 'timeouts'
- the kernel is still tick-based, but objects take timeout values in
ms for forward compatibility with a tickless kernel.
semaphores:
- Port of the nanokernel semaphores, which have the same basic behaviour
as the microkernel ones. Semaphore groups are not yet implemented.
- These semaphores are enhanced in that they accept an initial count and a
count limit. This allows configuring them as binary semaphores, and also
provisioning them without having to "give" the semaphore multiple times
before using them.
mutexes:
- Straight port of the microkernel mutexes. An init function is added to
allow defining them at runtime.
pipes:
- straight port
timers:
- amalgamation of nano and micro timers, with all functionalities
intact.
events:
- re-implementation, using semaphores and workqueues.
mailboxes:
- straight port
message queues:
- straight port of microkernel FIFOs
memory maps:
- straight port
workqueues:
- Basically, have all APIs follow the k_ naming rule, and use the _timeout
subsystem from the unified kernel directory, and not the _nano_timeout
one.
stacks:
- Port of the nanokernel stacks. They can now have multiple threads
pending on them and threads can wait with a timeout.
LIFOs:
- Straight port of the nanokernel LIFOs.
FIFOs:
- Straight port of the nanokernel FIFOs.
Work by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>
Peter Mitsis <peter.mitsis@windriver.com>
Allan Stephens <allan.stephens@windriver.com>
Benjamin Walsh <benjamin.walsh@windriver.com>
Change-Id: Id3cadb3694484ab2ca467889cfb029be3cd3a7d6
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Kumar Gala