Introduction to OpenPOWER Firmware
==================================

The ``op-build`` project constructs a host firmware image for OpenPOWER
machines.

Firmware Components
-------------------

Buildroot_
  We use http://buildroot.net/ as the build system for assembling a firmware
  image. `op-build` is a "Buildroot overlay". We build a kernel and initramfs
  using buildroot to run the Petitboot boot loader in. We maintain a branch
  with a minimum number of patches on top of upstream buildroot.
op-build_
  A buildroot overlay that assembles OpenPOWER Firmware images.
SBE_
  the Self Boot Engine is the first unit inside the POWER processor to start
  executing. It's job is to set up a core and load Hostboot.
Hostboot_
  Low level system boot firmware. It brings up CPU cores, the OCC, Memory
  and hands control over to OPAL (skiboot)
OCC_
  The On Chip Controller is responsible for thermal limits and frequency
  management.
OPAL
  The OpenPOWER Abstraction Layer, provided by skiboot
skiboot_
  skiboot implements OPAL (the OpenPOWER Abstraction Layer). Skiboot is
  boot and runtime firmware and is responsible for bringing up PCI and
  providing runtime abstractions to the running OS.
Linux_
  Once skiboot has finished setting up the machine, it hands control over
  to a Linux kernel. This kernel provides device drivers and userspace to
  run the bootloader, Petitboot. We maintain our own branch with a minimal
  number of patches on top of the latest upstream stable release.
Petitboot_
  The bootloader. It is a normal user-space process running on Linux that
  searches the system for disks and network devices that it can boot the
  OS from.
HCODE_
  Firmware for the power management PPE. Implements heavy lifting for deeper
  STOP states.

.. _Buildroot: https://github.com/open-power/buildroot
.. _op-build: https://github.com/open-power/op-build
.. _SBE: https://github.com/open-power/sbe
.. _OCC: https://github.com/open-power/occ
.. _Hostboot: https://github.com/open-power/hostboot
.. _skiboot: https://open-power.github.io/skiboot/
.. _Linux: https://github.com/open-power/linux
.. _Petitboot: https://github.com/open-power/petitboot/
.. _HCODE: https://github.com/open-power/hcode

Introductory Videos
-------------------

There are a number of good recorded presentations from various conferences
around the world that have overviews and deep dives into various parts of
the firmware stack.

Here, we present technical presentations that may be useful in learning
about topics relevant to OpenPOWER firmware development.

For broader OpenPOWER topics, check out the following channels:

- `OpenPOWER Foundation` <https://github.com/open-power/op-build/pull/2983>`_

Introductory
^^^^^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=a4XGvssR-ag
.. youtube:: https://www.youtube.com/watch?v=hcLhKjxa-40

Secure Boot
^^^^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=hwB1bkXQep4

Interfaces and standards
^^^^^^^^^^^^^^^^^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=2TroT3ORw0s

OpenCAPI
^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=h3pLBDCqY-I

.. youtube:: https://www.youtube.com/watch?v=K4dhx0ctjkQ

XIVE Interrupt Controller
^^^^^^^^^^^^^^^^^^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=s88beMQWkks

Petitboot
^^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=4JbDb4bRBK4
.. youtube:: https://www.youtube.com/watch?v=oxmMJMibZQ8

Booting Faster
^^^^^^^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=fTLsS_QZ8us

Testing
^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=znEM2xqJhBU

Bringup and customisation
^^^^^^^^^^^^^^^^^^^^^^^^^

.. youtube:: https://www.youtube.com/watch?v=v73Nw7NDxYI

.. youtube:: https://www.youtube.com/watch?v=dBEBQQYP_eI