Document Purpose: How to set up an OpenBMC development environment
Audience: Programmer familiar with Linux and BMCs
Prerequisites: Current Linux, Mac, or Windows system
OpenBMC uses the Yocto Project as its underlying building and distribution generation framework. The main OpenBMC README provides information on getting up and going with Yocto and OpenBMC. There are mechanisms to use this process to build your changes but it can be slow and cumbersome for initial debug and validation of your software. This guide focuses on how to test new changes quickly using the OpenBMC Software Development Kit (SDK) and QEMU.
The SDK is a group of packages that are built during a BitBake operation. BitBake is the tool used to build Yocto based distributions. The SDK provides all required libraries and cross compilers to build OpenBMC applications. The SDK is not used to build entire OpenBMC flash images, it provides a mechanism to compile OpenBMC applications and libraries that you can then copy onto a running system for testing.
QEMU is a software emulator that can be used to run OpenBMC images.
This doc walks through the recommended steps for setting up an OpenBMC development environment and installing the needed SDK.
For testing purposes, this guide uses the Romulus system as the default because this is the system tested for each CI job, which means it's the most stable.
If you are running Linux, and are ok with installing some additional packages, then you can skip to step 3.
The recommended OpenBMC development environment is the latest Ubuntu LTS release. Other versions of Linux may work but you are using that at your own risk. If you have Windows or Mac OS then VirtualBox is the recommended virtualization tool to run the development environment.
Both have free versions available for what you need. VirtualBox is what the majority of core OpenBMC development is using. Note: If you want to use this VM to BitBake a full OpenBMC image, you'll want to allocate as many resources as possible. Ideal minimum resources are 8 threads, 16GB memory, 200GB hard drive. Just using for SDK builds and QEMU should work fine with the normal defaults on a VM.
The majority of OpenBMC development community uses Ubuntu. The qemu below is built on 18.04 but whatever is most recent should work. The same goes for other Linux distributions like Fedora but again, these are not tested nearly as much by the core OpenBMC team as Ubuntu.
VirtualBox Tips - You'll want copy/paste working between your VM and Host. To do that, once you have your VM up and running:
Refer to Prerequisite link.
Note - In Ubuntu, a "sudo apt-get update" will probably be needed before installing the packages.
The OpenBMC Software Development Kit (SDK) contains a cross-toolchain and a set libraries for working on OpenBMC applications. The SDK is installed on the machine you will use to develop applications for OpenBMC and not on the BMC itself.
Generally, SDKs for one BMC cannot be used for developing software for other BMCs. This can be due to platform ABI, libc or kernel differences, or any other number of choices made in the configuration of the firmware.
Romulus is the BMC platform used for the purpose of this walk-through.
To begin working with the SDK:
mkdir -p ~/sdk cd ~/sdk wget https://jenkins.openbmc.org/job/latest-master-sdk/label=docker-builder,target=romulus/lastSuccessfulBuild/artifact/deploy/sdk/oecore-x86_64-arm1176jzs-toolchain-nodistro.0.sh chmod u+x oecore-x86_64-arm1176jzs-toolchain-nodistro.0.sh
Choose an appropriate location and name. It's a good idea to include the date and system supported by that SDK in the directory name. For example:
mkdir -p ~/sdk/romulus-`date +%F`
Run the following command to install the SDK. When command asks you to "Enter target directory for SDK", enter the directory you created in the previous step.
./oecore-x86_64-arm1176jzs-toolchain-nodistro.0.sh
The installation script will indicate progress and give completion messages like this:
SDK has been successfully set up and is ready to be used. Each time you wish to use the SDK in a new shell session, you need to source the environment setup script e.g. $ . /...path-to-sdk.../environment-setup-arm1176jzs-openbmc-linux-gnueabi
Ensure no errors. The command to do this will be provided at the end of installation. To make your shell use the new SDK environment, you must source its environment-setup script which was created in the previous step. You may wish to save the required command, for example, cut/paste the text above into a README.
That's it, you now have a working development environment for OpenBMC!
wget https://jenkins.openbmc.org/job/latest-qemu-x86/lastSuccessfulBuild/artifact/qemu/build/qemu-system-arm chmod u+x qemu-system-arm
wget https://jenkins.openbmc.org/job/latest-master/label=docker-builder,target=romulus/lastSuccessfulBuild/artifact/openbmc/build/tmp/deploy/images/romulus/obmc-phosphor-image-romulus.static.mtd
Note - For REST and SSH to work into your QEMU session, you must connect up some host ports to the REST and SSH ports in your QEMU session. In this example, it just uses 2222 and 2443. You can use whatever you prefer.
./qemu-system-arm -m 256 -M romulus-bmc -nographic -drive file=./obmc-phosphor-image-romulus.static.mtd,format=raw,if=mtd -net nic -net user,hostfwd=:127.0.0.1:2222-:22,hostfwd=:127.0.0.1:2443-:443,hostname=qemu
Note - By default, Jenkins and openbmc-test-automation use SSH and HTTPS ports 22 and 443, respectively. SSH connection to use a user-defined port 2222 might not be successful. To use SSH port 22 and HTTPS port 443:
./qemu-system-arm -m 256 -machine romulus-bmc -nographic -drive file=./obmc-phosphor-image-romulus.static.mtd,format=raw,if=mtd -net nic -net user,hostfwd=:127.0.0.1:22-:22,hostfwd=:127.0.0.1:443-:443,hostfwd=tcp:127.0.0.1:80-:80,hostfwd=tcp:127.0.0.1:2200-:2200,hostfwd=udp:127.0.0.1:623-:623,hostfwd=udp:127.0.0.1:664-:664,hostname=qemu
Login using default root/0penBmc login (Note the 0 is a zero).
You'll see a lot of services starting in the console, you can start running the obmcutil tool to check the state of the OpenBMC state services. When you see the following then you have successfully booted to "Ready" state.
root@openbmc:~# obmcutil state CurrentBMCState : xyz.openbmc_project.State.BMC.BMCState.Ready CurrentPowerState : xyz.openbmc_project.State.Chassis.PowerState.Off CurrentHostState : xyz.openbmc_project.State.Host.HostState.Off
Note To exit (and kill) your QEMU session run: ctrl+a x
yocto has tools for building and running qemu. These tools avoid some of the configuration issues that come from downloading a prebuilt image, and mofifying binaries. Using yocto qemu also uses the TAP interface which some find be more stable. This is particularly useful when debugging at the application level.
source setup romulus myBuild/build
MACHINE ??= "qemux86"
devtool modify bmcweb myNewLocalbmcweb/
MACHINE=qemux86 bitbake obmc-phosphor-image
runqemu myBuild/build/tmp/deploy/images/qemux86/ nographic \
qemuparams="-m 2048"