Build ACRN from Source¶

Introduction¶

Following a general embedded system programming model, the ACRN hypervisor is designed to be customized at build-time per hardware platform and per usage scenario, rather than one binary for all scenarios.

The hypervisor binary is generated based on Kconfig configuration settings. Instruction about these settings can be found in Modify the hypervisor configuration.

Note

A generic configuration named hypervisor/arch/x86/configs/generic.config is provided to help developers try out ACRN more easily. This configuration will likely work for most x86-based platforms, supported with limited features. This configuration can be enabled by specifying BOARD=generic in the make command line.

A primary reason one binary for all platforms and all usage scenarios is not supported is because dynamic configuration parsing is restricted in ACRN hypervisor, for the following considerations:

Meeting functional safety requirements Absence of dynamic objects is required in functional safety standards. Implementation of dynamic parsing would introduce dynamic objects. Avoiding use of dynamic parsing would help the ACRN hypervisor meet functional safety requirements.
Reduce complexity ACRN is a lightweight reference hypervisor, built for embedded IoT. As new platforms for embedded systems are rapidly introduced, support for one binary would require more and more complexity in the hypervisor, something we need to avoid.
Keep small footprint Implementation of dynamic parsing would introduce hundreds or thousands of code. Avoiding dynamic parsing would help keep Lines of Code (LOC) of the hypervisor in a desirable range (around 30K).
Improve boot up time Dynamic parsing at runtime would increase the boot up time. Using build-time configuration and not dynamic parsing would help improve boot up time of the hypervisor.

You can build the ACRN hypervisor, device model, and tools from source, by following these steps.

Install build tools and dependencies¶

ACRN development is supported on popular Linux distributions, each with their own way to install development tools:

Note

ACRN uses menuconfig, a python3 text-based user interface (TUI) for configuring hypervisor options and using python’s kconfiglib library.

On a Clear Linux OS development system, install the necessary tools:

$ sudo swupd bundle-add os-clr-on-clr os-core-dev python3-basic
$ pip3 install --user kconfiglib

On a Ubuntu/Debian development system:

$ sudo apt install gcc \
     git \
     make \
     gnu-efi \
     libssl-dev \
     libpciaccess-dev \
     uuid-dev \
     libsystemd-dev \
     libevent-dev \
     libxml2-dev \
     libusb-1.0-0-dev \
     python3 \
     python3-pip \
     libblkid-dev \
     e2fslibs-dev \
     pkg-config
$ sudo pip3 install kconfiglib

Note

You need to use gcc version 7.3.* or higher else you will run into issue #1396. Follow these instructions to install the gcc-7 package on Ubuntu 16.04:

$ sudo add-apt-repository ppa:ubuntu-toolchain-r/test
$ sudo apt update
$ sudo apt install g++-7 -y
$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 60 \
                     --slave /usr/bin/g++ g++ /usr/bin/g++-7

Note

ACRN development requires binutils version 2.27 (or higher). You can verify your version of binutils with the command apt show binutils. While Ubuntu 18.04 has a new version of binutils the default version on Ubuntu 16.04 needs updating (see issue #1133).

$ wget https://mirrors.ocf.berkeley.edu/gnu/binutils/binutils-2.27.tar.gz
$ tar xzvf binutils-2.27.tar.gz && cd binutils-2.27
$ ./configure
$ make
$ sudo make install

Note

Ubuntu 14.04 requires libsystemd-journal-dev instead of libsystemd-dev as indicated above.

On a Fedora/Redhat development system:

$ sudo dnf install gcc \
     git \
     make \
     findutils \
     gnu-efi-devel \
     libuuid-devel \
     openssl-devel \
     libpciaccess-devel \
     systemd-devel \
     libxml2-devel \
     libevent-devel \
     libusbx-devel \
     python3 \
     python3-pip \
     libblkid-devel \
     e2fsprogs-devel
$ sudo pip3 install kconfiglib

On a CentOS development system:

$ sudo yum install gcc \
        git \
        make \
        gnu-efi-devel \
        libuuid-devel \
        openssl-devel \
        libpciaccess-devel \
        systemd-devel \
        libxml2-devel \
        libevent-devel \
        libusbx-devel \
        python34 \
        python34-pip \
        libblkid-devel \
        e2fsprogs-devel
$ sudo pip3 install kconfiglib

Note

You may need to install EPEL for installing python3 via yum for CentOS 7. For CentOS 6 you need to install pip manually. Please refer to https://pip.pypa.io/en/stable/installing for details.

Get the ACRN hypervisor source code¶

The acrn-hypervisor repository has four main components in it:

The ACRN hypervisor code located in the hypervisor directory
The EFI stub code located in the misc/efi-stub directory
The ACRN devicemodel code located in the devicemodel directory
The ACRN tools source code located in the misc/tools directory

Follow this step to get the acrn-hypervisor source code:

$ git clone https://github.com/projectacrn/acrn-hypervisor

Choose the ACRN scenario¶

Note

Documentation about the new ACRN use-case scenarios is a work-in-progress on the master branch as we work towards the v1.2 release.

Currently ACRN hypervisor defines these typical usage scenarios:

SDC:: The SDC (Software Defined Cockpit) scenario defines a simple automotive use-case where there is one pre-launched Service VM and one post-launched User VM.
SDC2:: SDC2 (Software Defined Cockpit 2) is an extended scenario for an automotive SDC system. SDC2 defined one pre-launched Service VM and up to three post-launched VMs.
LOGICAL_PARTITION:: This scenario defines two pre-launched VMs.
INDUSTRY:: This is a typical scenario for industrial usage with up to four VMs: one pre-launched Service VM, one post-launched Standard VM for Human interaction (HMI), and one or two post-launched RT VMs for real-time control.
HYBRID:: This scenario defines a hybrid use-case with three VMs: one pre-launched VM, one pre-launched Service VM, and one post-launched Standard VM.

You can select a build scenario by changing the default Kconfig name in the choice block of ACRN Scenario in arch/x86/Kconfig. The corresponding VM configuration files in the corresponding scenarios/$SCENARIO_NAME/ folder.

$ cd  acrn-hypervisor/hypervisor
$ sudo vim arch/x86/Kconfig
# <Fill the scenario name into below and save>

choice
             prompt "ACRN Scenario"
             default SDC

See the Supported Hardware document for information about the platform needs for each scenario.

Modify the hypervisor configuration¶

The ACRN hypervisor leverages Kconfig to manage configurations, powered by Kconfiglib. A default configuration is generated based on the board you have selected via the BOARD= command line parameter. You can make further changes to that default configuration to adjust to your specific requirements.

To generate hypervisor configurations, you need to build the hypervisor individually. The following steps generate a default but complete configuration, based on the platform selected, assuming that you are under the top-level directory of acrn-hypervisor. The configuration file, named .config, can be found under the target folder of your build.

$ make defconfig BOARD=nuc6cayh

The BOARD specified is used to select a defconfig under arch/x86/configs/. The other command-line based options (e.g. RELEASE) take no effects when generating a defconfig.

To modify the hypervisor configurations, you can either edit .config manually, or invoke a TUI-based menuconfig, powered by kconfiglib, by executing make menuconfig. As an example, the following commands, assuming that you are under the top-level directory of acrn-hypervisor, generate a default configuration file for UEFI, allow you to modify some configurations and build the hypervisor using the updated .config.

$ make menuconfig              # Modify the configurations per your needs

Note

Menuconfig is python3 only.

Refer to the help on menuconfig for a detailed guide on the interface.

$ pydoc3 menuconfig

Build the hypervisor, device model and tools¶

Now you can build all these components in one go as follows:

$ cd ../                      # Enter top-level folder of acrn-hypervisor source
$ make FIRMWARE=uefi          # Build the UEFI hypervisor with the new .config

The build results are found in the build directory. You can specify use a different Output folder by setting the O make parameter, for example: make O=build-nuc BOARD=nuc6cayh.

If you only need the hypervisor, then use this command:

$ make clean                              # Remove files previously built
$ make FIRMWARE=uefi hypervisor           # This will only build the hypervisor

You could also use FIRMWARE=sbl instead, to build the Intel SBL (Slim bootloader) hypervisor.

Follow the same instructions to boot and test the images you created from your build.

Save as default configuration¶

Currently the ACRN hypervisor looks for default configurations under hypervisor/arch/x86/configs/<BOARD>.config, where <BOARD> is the specified platform. The following steps allow you to create a defconfig for another platform based on a current one.

$ cd hypervisor
$ make defconfig BOARD=nuc6cayh
$ make menuconfig         # Modify the configurations
$ make savedefconfig      # The minimized config reside at build/defconfig
$ cp build/defconfig arch/x86/configs/xxx.config

Then you can re-use that configuration by passing the name (xxx in the example above) to ‘BOARD=’:

$ make defconfig BOARD=xxx