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. Instructions about these settings can be found in Build 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 works for most x86-based platforms; it is supported with limited features. It can be enabled by specifying BOARD=generic in the make command line.

One binary for all platforms and all usage scenarios is currently not supported, primarily because dynamic configuration parsing is restricted in the ACRN hypervisor for the following reasons:

Maintain functional safety requirements. Implementing dynamic parsing introduces dynamic objects, which violates 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 could require more and more complexity in the hypervisor, which is something we strive to avoid.
Maintain small footprint. Implementing dynamic parsing introduces hundreds or thousands of lines of code. Avoiding dynamic parsing helps keep the hypervisor’s Lines of Code (LOC) in a desirable range (less than 40K).
Improve boot up time. Dynamic parsing at runtime increases the boot up time. Using a build-time configuration and not dynamic parsing helps improve the boot up time of the hypervisor.

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. This user guide covers the different steps to configure and build ACRN natively on your distribution. Refer to the Build ACRN in Docker user guide for instructions on how to build ACRN using a container.

Note

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

Install the necessary tools for the following systems:

Clear Linux OS development system:

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

Ubuntu 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 \
     zlib1g-dev \
     libnuma-dev
$ sudo pip3 install kconfiglib

Note

Use gcc version 7.3.* or higher to avoid gcc compilation issues. Follow these instructions to install the gcc-7 package on Ubuntu 18.04:

$ 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

ACRN development requires binutils version 2.27 (or higher). Verify your version of binutils with the command apt show binutils.

Get the ACRN hypervisor source code¶

The acrn-hypervisor repository contains four main components:

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

Enter the following to get the acrn-hypervisor source code:

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

Build with the ACRN scenario¶

Currently, the ACRN hypervisor defines these typical usage scenarios:

SDC:: The SDC (Software Defined Cockpit) scenario defines a simple automotive use case that includes one pre-launched Service VM and one post-launched User VM.
LOGICAL_PARTITION:: This scenario defines two pre-launched VMs.
INDUSTRY:: This is a typical scenario for industrial usage with up to eight VMs: one pre-launched Service VM, five post-launched Standard VMs (for Human interaction etc.), one post-launched RT VMs (for real-time control), and one Kata container VM.
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.

Assuming that you are at the top level of the acrn-hypervisor directory, perform the following:

Note

The release version is built by default, RELEASE=0 builds the debug version.

Build the INDUSTRY scenario on the nuc7i7dnb:

$ make all BOARD=nuc7i7dnb SCENARIO=industry RELEASE=0

Build the HYBRID scenario on the whl-ipc-i5:

$ make all BOARD=whl-ipc-i5 SCENARIO=hybrid RELEASE=0

Build the SDC scenario on the nuc6cayh:

$ make all BOARD=nuc6cayh SCENARIO=sdc RELEASE=0

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

Build the hypervisor configuration¶

Modify the hypervisor configuration¶

The ACRN hypervisor leverages Kconfig to manage configurations; it is 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 must build the hypervisor individually. The following steps generate a default but complete configuration, based on the platform selected, assuming that you are at the top level of the acrn-hypervisor directory. The configuration file, named .config, can be found under the target folder of your build.

$ cd hypervisor
$ 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 effect when generating a defconfig.

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

# Modify the configurations per your needs
$ cd ../         # Enter top-level folder of acrn-hypervisor source
$ make menuconfig -C hypervisor BOARD=kbl-nuc-i7   <input scenario name>

Note that 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 at once as follows:

$ make FIRMWARE=uefi       # Build the UEFI hypervisor with the new .config

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

If you only need the hypervisor, use this command:

$ make clean                       # Remove files previously built
$ make -C hypervisor
$ make -C misc/efi-stub HV_OBJDIR=$PWD/hypervisor/build EFI_OBJDIR=$PWD/hypervisor/build

The acrn.efi will be generated in the ./hypervisor/build/acrn.efi directory hypervisor.

As mentioned in ACRN Configuration Tool, the Board configuration and VM configuration can be imported from XML files. If you want to build the hypervisor with XML configuration files, specify the file location as follows (assuming you’re at the top level of the acrn-hypervisor directory):

$ make BOARD_FILE=$PWD/misc/acrn-config/xmls/board-xmls/nuc7i7dnb.xml \
SCENARIO_FILE=$PWD/misc/acrn-config/xmls/config-xmls/nuc7i7dnb/industry.xml FIRMWARE=uefi TARGET_DIR=xxx

Note

The BOARD and SCENARIO parameters are not needed because the information is retrieved from the corresponding BOARD_FILE and SCENARIO_FILE XML configuration files. The TARGET_DIR parameter specifies what directory is used to store configuration files imported from XML files. If the TARGED_DIR is not specified, the original configuration files of acrn-hypervisor would be overridden.

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