===============================================
UHD - Firmware and FPGA Image Application Notes
===============================================

.. contents:: Table of Contents

---------------
Images Overview
---------------
Every USRP device must be loaded with special firmware and FPGA images.
The methods of loading images into the device vary among devices:

* **USRP1:** The host code will automatically load the firmware and FPGA at runtime.
* **USRP2:** The user must manually write the images onto the USRP2 SD card.
* **USRP-N Series:** The user programs an image into on-board storage, which
  then is automatically loaded at runtime.
* **USRP-E Series:** The host code will automatically load the FPGA at runtime.
* **USRP-B Series:** The host code will automatically load the FPGA at runtime.
* **USRP-X Series:** The user programs an image into on-board storage, which
  then is automatically loaded at runtime. 

----------------
Pre-built Images
----------------

Pre-built images are available for download.

* `Master Branch images <http://files.ettus.com/binaries/master_images/>`_
* `Maint Branch images <http://files.ettus.com/binaries/maint_images/>`_

The pre-built images come in two forms:

* bundled with UHD software in a platform-specific installer
* stand-alone platform-independent archive files

^^^^^^^^^^^^^^^^^^^^^
UHD Images Downloader
^^^^^^^^^^^^^^^^^^^^^

The UHD images downloader downloads UHD images compatible with the host code
and places them in the default images directory.

By default, it can be found at: **<install-path>/lib/uhd/utils/uhd_images_downloader.py**

By default, it installs images to: **<install-path>/share/uhd/images**

^^^^^^^^^^^^^^^^^^^
Platform installers
^^^^^^^^^^^^^^^^^^^
The UNIX-based installers will install the images into **/usr/share/uhd/images**.

The Windows installers will install the images into **C:/Program Files/UHD/share/uhd/images**.

^^^^^^^^^^^^^^^
Archive install
^^^^^^^^^^^^^^^
When installing images from an archive, there are two options:

**Option 1:**

Unpack the archive into the UHD installation prefix.
UHD software will always search **<install-path>/share/uhd/images** for image files.
Where **<install-path>** was set by the **CMAKE_INSTALL_PREFIX** at configure-time.

**Option 2:**

Unpack the archive anywhere and set the **UHD_IMAGES_PATH** environment variable.
**UHD_IMAGES_PATH** may contain a list of directories to search for image files.

---------------
Building Images
---------------

The UHD source repository comes with the source code necessary to build
both firmware and FPGA images for all supported devices.

The build commands for a particular image can be found in **<uhd-repo-path>/images/Makefile**.

^^^^^^^^^^^^^^^^^^
Xilinx FPGA builds
^^^^^^^^^^^^^^^^^^
USRP Xilinx FPGA images are built with two different versions of ISE, depending
on the device.

The build requires that you have a UNIX-like environment with **Make**.
Make sure that **xtclsh** from the Xilinx ISE bin directory is in your **$PATH**.


**Xilinx ISE 14.7**
* USRP X3x0 Series
* USRP B2x0

See **<uhd-repo-path>/fpga/usrp3/top/**.

**Xilinx ISE 12.2**
* USRP N2x0
* USRP B1x0
* USRP E1x0
* USRP2

See **<uhd-repo-path>/fpga/usrp2/top/**.

^^^^^^^^^^^^^^^^^^^
ZPU firmware builds
^^^^^^^^^^^^^^^^^^^
The ZPU GCC compiler is required to build the ZPU firmware images.
The build requires that you have a UNIX-like environment with **CMake** and **Make**.
Make sure that **zpu-elf-gcc** is in your **$PATH**.

See **<uhd-repo-path>/firmware/zpu**.

^^^^^^^^^^^^^^^^^^
Altera FPGA builds
^^^^^^^^^^^^^^^^^^
Quartus is required to build the Altera FPGA image for the USRP1.
Pre-built images can also be found in **<uhd-repo-path>/fpga/usrp1/rbf**.

See **<uhd-repo-path>/fpga/usrp1/toplevel/***.

^^^^^^^^^^^^^^^^^^^
FX2 firmware builds
^^^^^^^^^^^^^^^^^^^
The SDCC compiler is required to build the FX2 firmware images.
The build requires that you have a UNIX-like environment with **CMake** and **Make**.

See **<uhd-repo-path>/firmware/fx2**.