.. _galileo:

Board Configuration: galileo
###############################

Overview
********

Developers can use the galileo board configuration
to build a Zephyr Kernel that runs on a Galileo Development Board (Gen 1 or Gen 2).

This board configuration enables kernel support for the board's Quark SoC,
along with the following devices:

* High Precision Event Timer (HPET)

* Peripheral Component Interconnect (PCI) bus query

* Serial Ports in Polling and Interrupt Driven Modes

See `Procedures`_ for using third-party tools to load an image onto the target.

.. note::
   This board configuration may work with similar boards
   that are not officially supported.

Supported Boards
****************

This section provides information about the physical characteristics of boards
that the galileo board configuration supports.
Subsections contain detailed information on pin names, jumper settings, memory mappings,
and board component layout.

Pin Names
=========

For a component layout diagram showing pin names, see page 46 of the
`Intel® Quark SoC X1000 Datasheet`_.

See also the `Intel® Galileo Datasheet`_.

For the Galileo Board Connection Diagram see page 9 of the `Intel® Galileo Board User Guide`_.


Jumpers & Switches
==================

The kernel uses the Galileo default jumper settings except for the IOREF jumper,
which must be set to match the external operating voltage of either 3.3 V or 5 V.

The Galileo default switch settings are:

+--------+--------------+
| Jumper | Setting      |
+========+==============+
| IOREF  | 3.3V or 5V   |
+--------+--------------+
| VIN    | 5V  Jumpered |
+--------+--------------+

For more information, see page 14 of the
`Intel® Galileo Board User Guide`_.


Memory Mappings
===============

The galileo board configuration uses default hardware memory map
addresses and sizes.

For a list of memory mapped registers, see page 868 of the
`Intel® Quark SoC X1000 Datasheet`_.


Component Layout
================

See page 3 of the Intel® Galileo Datasheet for a component layout
diagram. Click the link to open the `Intel® Galileo Datasheet`_.


For a block diagram, see page 38 of the `Intel® Quark SoC X1000 Datasheet`_.


Supported Features
******************

The galileo board configuration supports the following hardware features:

* HPET

* PCI bus

* Advanced Programmed Interrupt Controller (APIC)

* Serial Ports in Polling and Interrupt Driven Modes

+-----------+------------+-----------------------+
| Interface | Controller | Driver/Component      |
+===========+============+=======================+
| HPET      | on-chip    | system clock          |
+-----------+------------+-----------------------+
| PCI       | on-chip    | PCI library           |
+-----------+------------+-----------------------+
| APIC      | on-chip    | interrupt controller  |
+-----------+------------+-----------------------+
| UART      | on-chip    | serial port-polling;  |
|           |            | serial port-interrupt |
+-----------+------------+-----------------------+

The kernel currently does not support other hardware features.
See the `Intel® Quark Core Hardware Reference Manual`_ for a
complete list of Galileo board hardware features, and the
`Intel® Quark Software Developer Manual for Linux`_


PCI
===

The PCI driver initiates a PCI library scan of the PCI bus for any attached devices.
When detected, the devices are initialized.

.. note::
   The PCI library does not support 64-bit devices.
   Memory address and size storage only require 32-bit integers.

Serial Port Polling Mode Support
================================

The polling mode serial port allows debug output to be printed.

For more information, see `Intel® Quark SoC X1000 Datasheet`_,
section 18.3.3 FIFO Polled-Mode Operation


Serial Port Interrupt Mode Support
==================================

The interrupt mode serial port provides general serial communication
and external communication.

For more information, see `Intel® Quark SoC X1000 Datasheet`_, section 21.12.1.4.5 Poll Mode


Interrupt Controller
====================

The galileo board configuration uses the kernel's static
Interrupt Descriptor Table (IDT) to program the
Advanced Programmable Interrupt Controller (APIC)
interrupt redirection table.

Interrupts
----------

+-----+-------+---------+--------------------------+
| IRQ | Name  | Remarks | Used by Zephyr Kernel    |
+=====+=======+=========+==========================+
| 17  | INTB  | UART    | serial port when used in |
|     |       |         | interrupt mode           |
+-----+-------+---------+--------------------------+
| 20  | timer | HPET    | timer driver             |
+-----+-------+---------+--------------------------+

HPET System Clock Support
=========================

Galileo uses HPET timing with legacy-free timer support. The galileo platform
configuration uses HPET as a system clock timer.

Procedures
**********

Use the following procedures for booting an image on a Galileo board.

* `Creating a GRUB2 Boot Loader Image from a Linux Host`_

* `Preparing the Boot Device`_

* `Booting the Galileo Board`_


Creating a GRUB2 Boot Loader Image from a Linux Host
====================================================

If you are having problems running an application using the default GRUB
of the hardware, follow these steps to test on Galileo2 boards using a custom
GRUB.

#. Install the requirements to build GRUB on your host machine.

   On Ubuntu, type:

   .. code-block:: console

    $ sudo apt-get install gnu-efi:i386 bison libopts25 \
    libselinux1-dev autogen m4 autoconf help2man libopts25-dev flex \
    libfont-freetype-perl automake autotools-dev libfreetype6-dev \
    texinfo

   On Fedora, type:

   .. code-block:: console

     $ sudo dnf install gnu-efi bison m4 autoconf help2man flex \
        automake texinfo

#. Clone and build the GRUB repository using the script in Zephyr tree, type:

   .. code-block:: console

     $ cd $ZEPHYR_BASE
     $ ./scripts/build_grub.sh

#. Find the binary at :file:`$ZEPHYR_BASE/scripts/grub/bin/grub.efi`.


Preparing the Boot Device
=========================

Prepare either an SD-micro card or USB flash drive to boot the Zephyr
application image on a Galileo board. The following instructions apply to both
devices.


#. Set the board configuration to Galileo by changing the :command:`make`
   command to:

   .. code-block:: console

      $ make BOARD=galileo


#. Use one of these cables for serial output:

   `<http://www.ftdichip.com/Products/Cables/USBTTLSerial.htm>`_

#. Format a microSD as FAT

#. Create the following directories

   :file:`efi`

   :file:`efi/boot`

   :file:`kernel`

#. Copy the kernel file :file:`zephyr.strip` to the :file:`$SDCARD/kernel` folder.

#. Copy your built version of GRUB to :file:`$SDCARD/efi/boot/bootia32.efi`

#. Create :file:`$SDCARD/efi/boot/grub.cfg` containing the following:

   .. code-block:: console

      set default=0
      set timeout=10

      menuentry "Zephyr Kernel" {
         multiboot /kernel/zephyr.elf
      }

#. Insert the SDcard in the Galileo board.

#. Connect the board to the host system using the serial cable.

#. Configure your host system to watch for serial data.

   * On Linux, screen is a popular method for reading serial
      data.

   * On Windows, PuTTY has an option to set up configuration for
      serial data.

#. Power on the Galileo board.

Booting the Galileo Board
=========================

Boot the Galileo board from the boot device using GRUB2
with the boot loader present in the on-board flash.

.. note::
   A stripped project image file is automatically created when the
   project is built. The stripped image has removed debug
   information from the :file:`ELF` file.

Prerequisites
-------------

* The automatically created stripped Zephyr application image is
  in the project directory.

* A serial port is available for communication.

  .. note::
     For details on how to connect and configure the serial port,
     see the Getting Started guide that you received with the board.

Steps
-----

1. Insert the prepared boot device (micro-SD card or USB flash
   drive) into the board and start the board.

   The boot process begins and displays a large amount of output.

2. When the following output appears, press :kbd:`F7`:

   .. code-block:: console

     [Bds]BdsWait ...Zzzzzzzzzzzz...
     [Bds]BdsWait(5)..Zzzz...
     [Bds]BdsWait(4)..Zzzz...
     [Bds]Press [Enter] to directly boot.
     [Bds]Press [F7]    to show boot menu options.

3. From the menu that appears, select :guilabel:`UEFI Internal Shell`.

4. At the shell prompt enter:

   .. code-block:: console

     grub.efi

   GRUB2 starts and a menu shows entries for the items you added
   to the :file:`file grub.cfg`.

5. Select the image you want to boot and press :guilabel:`Enter`.

   When the boot process completes, you have finished booting the
   Zephyr application image.

Known Problems and Limitations
******************************

At this time, the kernel does not support the following:

* Isolated Memory Regions
* Serial port in Direct Memory Access (DMA) mode
* Ethernet
* Supervisor Mode Execution Protection (SMEP)

Bibliography
************

1. `Intel® Galileo Datasheet`_, Order Number: 329681-001US

.. _Intel® Galileo Datasheet:
   http://www.intel.com/newsroom/kits/quark/galileo/pdfs/Intel_Galileo_Datasheet.pdf

2. `Intel® Galileo Board User Guide`_.

.. _Intel® Galileo Board User Guide:
   http://download.intel.com/support/galileo/sb/galileo_boarduserguide_330237_001.pdf

3. `Intel® Quark SoC X1000 Datasheet`_, Order Number: 329676-001US

.. _Intel® Quark SoC X1000 Datasheet:
   https://communities.intel.com/servlet/JiveServlet/previewBody/
   21828-102-2-25120/329676_QuarkDatasheet.pdf

4. `Intel® Quark Core Hardware Reference Manual`_.

.. _Intel® Quark Core Hardware Reference Manual:
   http://caxapa.ru/thumbs/497461/Intel_Quark_Core_HWRefMan_001.pdf

5. `Intel® Quark Software Developer Manual for Linux`_.

.. _Intel® Quark Software Developer Manual for Linux:
   http://www.intel.com/content/dam/www/public/us/en/documents/manuals/quark-x1000-linux-sw-developers-manual.pdf