80 lines
2.7 KiB
ReStructuredText
80 lines
2.7 KiB
ReStructuredText
.. _introducing_zephyr:
|
|
|
|
Introducing Zephyr
|
|
##################
|
|
|
|
The Zephyr OS is based on a small-footprint kernel designed for use on
|
|
resource-constrained systems: from simple embedded environmental sensors and LED
|
|
wearables to sophisticated smart watches and IoT wireless gateways.
|
|
|
|
The Zephyr kernel supports multiple architectures, including ARM Cortex-M, Intel
|
|
x86, ARC, NIOS II, Tensilica Xtensa and RISC V. The full list of supported
|
|
boards can be found :ref:`here <boards>`.
|
|
|
|
Licensing
|
|
*********
|
|
|
|
Zephyr uses the `Apache 2.0 license`_ (as found in the LICENSE file in the
|
|
project's `GitHub repo`_). There are some
|
|
imported or reused components of the Zephyr project that use other licensing,
|
|
as described in :ref:`Zephyr_Licensing`.
|
|
|
|
.. _Apache 2.0 license:
|
|
https://github.com/zephyrproject-rtos/zephyr/blob/master/LICENSE
|
|
|
|
.. _GitHub repo: https://github.com/zephyrproject-rtos/zephyr
|
|
|
|
|
|
Distinguishing Features
|
|
***********************
|
|
|
|
The Zephyr kernel offers a number of features that distinguish it from other
|
|
small-footprint OSes:
|
|
|
|
#. **Single address-space**. Combines application-specific code
|
|
with a custom kernel to create a monolithic image that gets loaded
|
|
and executed on a system's hardware. Both the application code and
|
|
kernel code execute in a single shared address space.
|
|
|
|
#. **Highly configurable**. Allows an application to incorporate *only*
|
|
the capabilities it needs as it needs them, and to specify their
|
|
quantity and size.
|
|
|
|
#. **Compile-time resource definition**. Allows system resources
|
|
to be defined at compile-time, which reduces code size and
|
|
increases performance.
|
|
|
|
#. **Minimal error checking**. Provides minimal runtime error checking
|
|
to reduce code size and increase performance. An optional error-checking
|
|
infrastructure is provided to assist in debugging during application
|
|
development.
|
|
|
|
#. **Extensive suite of services**. Offers a number of familiar services
|
|
for development:
|
|
|
|
* *Multi-threading Services* for priority-based, non-preemptive and
|
|
preemptive threads with optional round robin time-slicing.
|
|
|
|
* *Interrupt Services* for compile-time registration of interrupt handlers.
|
|
|
|
* *Memory Allocation Services* for dynamic allocation and freeing of
|
|
fixed-size or variable-size memory blocks.
|
|
|
|
* *Inter-thread Synchronization Services* for binary semaphores,
|
|
counting semaphores, and mutex semaphores.
|
|
|
|
* *Inter-thread Data Passing Services* for basic message queues, enhanced
|
|
message queues, and byte streams.
|
|
|
|
* *Power Management Services* such as tickless idle and an advanced idling
|
|
infrastructure.
|
|
|
|
.. include:: ../../README.rst
|
|
:start-after: start_include_here
|
|
|
|
|
|
Fundamental Terms and Concepts
|
|
******************************
|
|
|
|
See :ref:`glossary`
|