Zephyr Project @ VHS

The following instructions can be used to develop an application using Zephyr and program it on to a suitable board.

• PC with 64 bit virtualization
• Internet connection
• Suitable board (e.g. B-L475E-IOT01A Discovery kit)
• Cable to connect board (e.g. USB Type-A to Micro-B cable)

Zephyr requires a 64 bit version of Linux. In order to run a 64 bit version of Linux in a Virtual Machine, your computer must be capable of 64 bit virtualization. This may require changing a setting in your BIOS. A web search of your particular model should help clarify if your machine is capable of 64 bit virtualization and if any steps are required to enable this feature.

More details on setting up a Linux Virtual Machine on Windows can be found here: https://www.storagecraft.com/blog/the-dead-simple-guide-to-installing-a-linux-virtual-machine-on-windows/

There are several different programs for virtual machines. Oracle Virtual Box was chosen as it is fairly popular, free, and cross-platform.

• https://www.virtualbox.org/wiki/Downloads

Zephyr requires a 64 bit version of Linux.

These instructions were developed using a Xubuntu distribution (https://xubuntu.org/) but should work equally well for other Linux distributions. A lightweight distribution may improve performance on a host machine with limited resources.

In Oracle Virtual Box, Create a new Virtual Machine.

• Give it an appropriate name (e.g. LinuxVM), select Linux as the type, and choose the version that matches the Linux OS you obtained in the previous step.

Note: If the versions only list 32 bit, your system may not be capable of virtualizing a 64 bit system or you may need to enable the option in the BIOS. Consult the Google.

• Select the amount of RAM you want to allocate to the Virtual Machine. The default 1024 MB seems to work fine.

• Create a new virtual hard drive. Again, the default setting of VDI should work fine. Give this file a name and choose where it is stored within your existing Windows file system. Adjust the slider or type in a specific number in the box to the right to specify the virtual hard drive size. At least 20 GB is recommended, as it is no trivial to extend the size after it is created.

In Oracle Virtual Box, start the Virtual Machine you created in the last session. You should be prompted to select a start-up disc.

• Navigate to and select the .iso of the Linux OS you downloaded in a previous step.
• Follow the instructions to install the Linux OS to your virtual machine.

It may be convenient to create a shared folder between your Windows machine and your Linux virtual machine:

Install Guest Tools:

• sudo apt-get install virtualbox-guest-dkms

Add permission for user to shared folder:

• sudo usrmod -G vboxsf -a <your username>

You can now add and configure a shared folder in Oracle Virtual Machine.

• DEVICES > SHARED FOLDERS > SHARED FOLDER SETTINGS

The following instructions are largely based on Instructions for Setting up the Development Environment Setup on Linux: https://www.zephyrproject.org/doc/getting_started/installation_linux.html

Open a terminal, and update the os:

• sudo apt-get update
• sudo apt-get upgrade

Install necessary packages:

• sudo apt-get install git make gcc g++ ncurses-dev gperf ccache doxygen dfu-util device-tree-compiler python3-ply python3-pip python-pip

Install serial communication program:

• sudo apt-get install minicom

Install CMake:

• git clone https://gitlab.kitware.com/cmake/cmake.git
• cd cmake/

Optional - check tags:

• git tag -l

Checkout version 3.8.2

• git checkout v3.8.2
• ./bootstrap && make -j8
• sudo make install

Optional - It may be necessary to check to see if the newly installed CMake is going to be called correctly:

• type -a cmake dpkg -S /usr/bin/cmake gvim -p ~/.bashrc ~/.pr ofile
• alias cmake='/usr/local/bin/cmake'

For SDK Version 0.9.2 :

• wget https://github.com/zephyrproject-rtos/meta-zephyr-sdk/releases/download/0.9.2/zephyr-sdk-0.9.2-setup.run
• chmod +x zephyr-sdk-0.9.2-setup.run
• sudo ./zephyr-sdk-0.9.2-setup.run

git clone https://github.com/zephyrproject-rtos/zephyr.git

Navigate to the Zephyr source code directory (e.g. /home/zephyr) and install required Python packages:

• pip3 install –user -r scripts/requirements.txt

The following instructions are some specific steps for programming the B-L475E-IOT01A Discovery kit board.

Manufacturer page:

• http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-tools/stm32-mcu-discovery-kits/b-l475e-iot01a.html

Zephyr Project Page:

• http://zephyr-docs.s3-website-us-east-1.amazonaws.com/online/dev/boards/arm/disco_l475_iot1/doc/disco_l475_iot1.html

• http://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-utilities/stsw-link009.html

• sudo apt-get install pkg-config autoconf automake libtool libusb-dev libusb-1.0-0-dev libhidapi-dev

Load rules from St Link firmware upgrade:

• http://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-programmers/stsw-link007.html

Copy rules from stsw-link007/AllPlatforms/StlinkRulesFilesForLinux over to /etc/udev/rules.d

• sudo cp *.rules /etc/udev/rules.d

Reload rules:

• sudo udevadm control –reload-rules

By default, you need to explicitly allow the virtual machine to connect to USB devices.

Connect the board to your computer using the USB cable. Make sure to connect to the jack marked “USB STLINK” (Not the USB OTG jack)

Enabled the connection in Oracle Virtual Box:

• DEVICES > USB
• Select “STMicroelectronics STM32 STLINK [0100]”

Set build variables:

• export ZEPHYR_GCC_VARIANT=zephyr
• export ZEPHYR_SDK_INSTALL_DIR=/opt/zephyr-sdk

Navigate to Zephyr directory:

• cd <zephyr_root_path>

Set build environment:

• source zephyr-env.sh

Navigate to Hello world code:

• cd $ZEPHYR_BASE/samples/hello_world/

Build code for the corresponding board configuration:

• mkdir -p build/disco_l475_iot1
• cd build/disco_l475_iot1
• cmake -DBOARD=disco_l475_iot1 ../..
• make -j8

If it isn't already, connect the board to your computer using the USB cable. Make sure you've configured the Virtual Machine access to the USB device as described above.

Flash the board with the program:

• make flash

Run a serial host program to connect with your board. You may want to execute these in a second terminal:

• minicom -D /dev/ttyACM0

Press the reset button on the board. If all has gone well, you should see:

Hello World! arm

• Zephyr Hello World
• Zephyr Data Logging

• General Info on Setting up Virtual Machine to Run Linux: https://www.linux.com/learn/why-when-and-how-use-virtual-machine
• Resize a Virtual Box guest Linux VDI under Windows Host: http://derekmolloy.ie/resize-a-virtualbox-disk/
• Zephyr Project @ VHS
• General Zephyr Code