This page will take you through the steps you need to follow to build and run QEMU from Source Code.

Building QEMU Source Code On a Linux Host:

Downloading QEMU from Xilinx

The Xilinx QEMU source code is available on the Xilinx Git server and can be downloaded using the following command.

git clone git://github.com/Xilinx/qemu.git
cd qemu

The command above will by default clone the master branch of QEMU. This generally is ahead of the version of QEMU released with PetaLinux. This means it has improvements and new features compared to the released version but is also is less thoroughly tested and could have unknown bugs.

If you want to build the source that was used for the released version of QEMU, please checkout the appropriate tag instead of the master branch.
This can be done by first finding a list of tags:

git tag -l

And then checking out the release you want to use:

git checkout tags/xilinx-v2020.1

QEMU Linux Dependencies

If the configure or build steps fail, it is possible some build dependencies are missing. On Ubuntu use the below command to install most of the dependencies needed for building QEMU (please note you may find additional dependencies based on your setup).

sudo apt install libglib2.0-dev libgcrypt20-dev zlib1g-dev autoconf automake libtool bison flex libpixman-1-dev

QEMU also includes submodules that will need to be checked out. Use the following command to checkout the appropriate submodules.

git submodule update --init dtc

Configuring QEMU

QEMU must be configured to build on the Linux host. This can be accomplished using the following command line.

mkdir build
cd build
../configure --target-list="aarch64-softmmu,microblazeel-softmmu" --enable-fdt --disable-kvm --disable-xen --enable-gcrypt

The command shown above configures QEMU to build aarch64-softmmu and microblazeel-softmmu targets. Use "./configure –help" to know all supported targets and optional features in QEMU. If no "--target-list" provided, QEMU will build all targets.

Building QEMU

The following command line builds QEMU to run on the host computer.

make -j4
# -j options specifies the number of jobs (commands) to run simultaneously. You may increase this to 16, 32 or more for faster build.

If the build is successful, an executable named qemu-system-aarch64 and qemu-system-microblazeel will be created in the /aarch64-softmmu and /microblazeel-softmmu sub-directory respectively.

To validate the build run below commands:

./aarch64-softmmu/qemu-system-aarch64 --help

Building device tree binaries:

Device trees are used by the QEMU provided by Xilinx to internally generate a machine model.

Install device tree compiler

If device-tree-compiler is not installed, please install it using below command:

apt-get install device-tree-compiler

Clone Xilinx QEMU device trees

git clone git://github.com/Xilinx/qemu-devicetrees.git
cd qemu-devicetrees

Build device trees

You must have dtc on your PATH or specify DTC=<path to device-tree-compiler executable> with the make command below:

make
# make DTC=<path to device-tree-compiler executable>

This will give you a folder called /LATEST which contains subdirectories for the different QEMU operating modes. Under these subdirectories are the board-specific device trees.

Running QEMU

QEMU can run in three ways:

1. Run Bare metal(standalone) applications on QEMU.
2. Run Linux on QEMU.

For running Linux on QEMU, please check PetaLinux boot section and look for the commands it prints when executing boot to Linux prompt step.

An example of these commands on a VCK190 machine may look like:

qemu-system-microblazeel \
-M microblaze-fdt \
 -serial mon:stdio \
 -display none \
 -device loader,addr=0xf0000000,data0xba020004,data-len=4 \
 -device loader,addr=0xf0000004,data=0xb800fffc,data-len=4 \
 -device loader,file=/scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/pmc_cdo.bin,addr=0xf2000000 \
 -device loader,file=/scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/BOOT_bh.bin,addr=0xf201e000,force-raw \
 -device loader,file=/scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/plm.elf \
 -hw-dtb /scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/versal-qemu-multiarch-pmc.dtb \
 -machine-path /tmp/qemu-shm \
 -device loader,addr=0xF1110624,data=0x0,data-len=4 \
 -device loader,addr=0xF1110620,data=0x1,data-len=4

qemu-system-aarch64 \
 -M arm-generic-fdt \
 -serial null \
 -serial null \
 -serial mon:stdio \
 -display none \
 -boot mode=5 \
 -drive if=sd,index=1,file=/scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/qemu_boot.img,format=raw \
 -device loader,file=/scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/rootfs.cpio.gz.u-boot,addr=0x04000000,force-raw \
 -device loader,file=/scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/Image,addr=0x00080000,force-raw \
 -gdb tcp::9000 \
 -net nic,netdev=eth0 \
 -netdev user,id=eth0,tftp=/tftpboot \
 -net nic \
 -hw-dtb /scratch/petalinux-images/xilinx-vck190-2020.2/pre-built/linux/images/versal-qemu-multiarch-ps.dtb \
 -machine-path /tmp/qemu-shm \
 -m 8G

However, these commands will vary from machine to machine.

Running bare metal applications will be talked about in the next section.