Using Zephyr as User OS¶
This tutorial describes how to run Zephyr as the User OS on the ACRN hypervisor. We are using Kaby Lake-based NUC (model NUC7i5DNHE) in this tutorial. Other ACRN supported platforms should work as well.
Introduction to Zephyr¶
The Zephyr RTOS is a scalable real-time operating-system supporting multiple hardware architectures, optimized for resource constrained devices, and built with safety and security in mind.
Steps for Using Zephyr as User OS¶
Build Zephyr
Follow the Zephyr Getting Started Guide to setup the Zephyr development environment.
The build process for ACRN UOS target is similar to other boards. We will build the Hello World sample for ACRN:
$ cd samples/hello_world $ mkdir build && cd build $ cmake -DBOARD=acrn .. $ make
This will build the application ELF binary in
samples/hello_world/build/zephyr/zephyr.elf
.Build grub2 boot loader image
We can build grub2 bootloader for Zephyr using
boards/x86/common/scripts/build_grub.sh
which locate in Zephyr Sourcecode.$ ./boards/x86/common/scripts/build_grub.sh x86_64
The EFI executable binary will be found at
boards/x86/common/scripts/grub/bin/grub_x86_64.efi
.Preparing the boot device
$ dd if=/dev/zero of=zephyr.img bs=1M count=35 $ mkfs.vfat -F 32 zephyr.img $ sudo mount `sudo losetup -f -P --show zephyr.img` /mnt
Create the following directories.
$ sudo mkdir -p /mnt/efi/boot $ sudo mkdir -p /mnt/kernel
Copy
zephyr.elf
andgrub_x86_64.efi
$ sudo cp boards/x86/common/scripts/grub/bin/grub_x86_64.efi /mnt/efi/boot/bootx64.efi $ sudo cp samples/hello_world/build/zephyr/zephyr.elf /mnt/kernel
Create
/mnt/efi/boot/grub.cfg
containing the following:set default=0 set timeout=10 menuentry "Zephyr Kernel" { multiboot /kernel/zephyr.elf }
Unmount the loopback device:
$ sudo umount /mnt
You now have a virtual disk image with a bootable Zephyr in
zephyr.img
. If the Zephyr build system is not the ACRN SOS, then you will need to transfer this image to the ACRN SOS (via, e.g, a USB stick or network )Follow Using SDC Mode on the NUC to boot “The ACRN Service OS” based on Clear Linux OS 28620 (ACRN tag: acrn-2019w14.3-140000p)
Boot Zephyr as User OS
On the ACRN SOS, prepare a directory and populate it with Zephyr files.
$ mkdir zephyr && cd zephyr $ cp /usr/share/acrn/samples/nuc/launch_zephyr.sh .
You will also need to copy the
zephyr.img
created in the above section into directoryzephyr
.Run the
launch_zephyr.sh
script to launch Zephyr as UOS.$ sudo ./launch_zephyr.sh
Then Zephyr will boot up automatically. You will see a console message from the hello_world sample application:
Hello World! acrn