bchemel / pysamloader

Python library for writing flash on Atmel's ARM chips via SAM-BA.

Introduction

pysamloader is a python library for writing flash on Atmel's ARM chips via SAM-BA. Originally written years ago when Atmel's standard tools were unavailable or unusable on Linux, it has been adapted to serve narrower but specific use cases.

Specifically, pysamloader is intended to be :

• Simple, particularly for an end-user
• Easily installable across platforms
• Usable from within larger python applications or scripts

Currently, pysamloader seems to be reasonably stable on a tiny set of supported devices.

If you happen to use pysamloader, or wish to use it, let me know along with any feedback you might have to ensure the tool is stable, reliable, and sufficiently versatile. Device support is easy enough to add, and I will do so as the need (and more importantly, the ability to test on other devices) presents itself. Pull requests are also welcome.

See the pysamloader/devices folder for included device support modules. Currently supported devices are :

.. documentedlist::
    :listobject: pysamloader.pysamloader.supported_devices
    :header: "Device" "Interface"

Features

pysamloader currently supports the following actions :

• Write device flash
• Optionally verify flash after writing
• Optionally set the GPNVM bits to boot from flash after writing
• Read and parse ChipID
• Read Unique Identifier from Embedded Flash
• Read Flash Descriptor

Requirements & Installation

Attention!

You might want to take a look at the pysamloader-gui package as well. It provides a simple GUI. If you are using the binary packages, it can be installed and used independent of this.

pysamloader should work on any platform which supports python. It is best tested on Linux followed by on Windows (10 and 7).

pysamloader supports both Python 2 (2.7.x) and Python 3 (>3.5). Python 2 support is likely to be removed in the near future.

In general, pysamloader is expected to be pip-installed. It can be safely installed into a virtualenv. As long as you have a functioning python installation of sufficient version, installing pysamloader would be simply :

$ pip install pysamloader

If you require pre-built binaries, they are available for 64-bit Linux and Windows. However, be aware that these binaries are not thoroughly tested, and your mileage may vary based on your specific operating system and machine architecture. You will also have to manually copy the included devices folder to the correct location. (See below)

If you wish to develop, modify the sources, or otherwise get the latest version, it can be installed from a clone of the git repository (or from a source package) as follows :

$ git clone https://github.com/chintal/pysamloader.git
$ cd pysamloader
$ pip install -e .

The pysamloader/devices folder contains the included device support modules, each of which is a python file with a single class of the same name, containing device specific information about one device. This folder can be copied into a separate location where you can safely add, remove, or modify device configuration as needed. This step is generally optional, but will be required if you are using the binary packages. The location is that provided by user_config_dir of the python appdirs package, specifically :

• Linux : ~/.config/pysamloader
• Windows : C:\Users\<username>\AppData\Roaming\Quazar Technologies\pysamloader

The current pysamloader windows .msi installer will create this folder and populate it as a part of the install process.

Usage

The primary entry point for use of pysamloader is as a console script.

For those in a hurry, the following is a quick example of how to use the script to burn app.bin to an ATSAM3U4E whose UART SAM-BA interface is accessible on \dev\ttyUSB1:

$ pysamloader --device ATSAM3U4E --port \dev\ttyUSB1 -g app.bin

Script usage and arguments are listed here. This help listing can also be obtained on the command line with pysamloader --help.

.. argparse::
    :module: pysamloader.cli
    :func: _get_parser
    :prog: pysamloader
    :nodefault:

Links & Other Information

Known Issues

• Writing to multiple flash planes is not currently supported. This application will always write to the first flash plane and will start at the beginning.
• The use of xmodem send file to write flash doesn't seem to work. Flash is instead written using SAM-BA write_word commands, which is about 20 times slower.

Future Directions

• Add support for libftdi/libd2xx/libusb based backend for cases where the device disables ftdi_sio for its normal operation.
• Add hooks for device auto-detection. Do not even bother to probe blindly for SAM-BA - that is too dangerous. Instead rely on apriori knowledge of signatures of device configuration, including VID, PID, Manufacturer, Product, Serial Number, and USB endpoint descriptors.

Links

The latest version of the documentation, including installation, usage, and API/developer notes can be found at ReadTheDocs.

The latest version of the sources can be found at GitHub. Please use GitHub's features to report bugs, request features, or submit pull/merge requests.

The principle author for pysamloader is Chintalagiri Shashank. The author can be contacted if necessary via the information on the author's github profile . See the AUTHORS file for a full list of collaborators and/or contributing authors, if any.

pysamloader is distributed under the terms of the GPLv3 license . A copy of the text of the license is included along with the sources.