Commit Graph

3 Commits

Author SHA1 Message Date
Benjamin Walsh 516e79c8da kernel: disable INIT_STACKS by default
Now that we're out of the unified kernel development phase, turn off
that debugging option.

Change-Id: I89decbdf445b1ba111a829edf2c8a36846419586
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-24 16:37:01 +00:00
Allan Stephens dd07b4779f kernel: Eliminate use of KERNEL_V2 configuration option
The unified kernel is now the only supported kernel, so this
option is unnessary. Eliminating this option also enables
the removal of some legacy code that is no longer required.

Change-Id: Ibfc339d643c8de16a2ed2009c9b468848b8b4972
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
2016-11-12 12:04:39 +00:00
Benjamin Walsh 456c6daa9f unified: initial unified kernel implementation
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>
2016-09-13 17:12:55 -04:00