If your VM is headless (i.e. console in/out is the primary way of interacting with it), you can spawn it by passing a JSON config file to the VirtualizationService via the vm tool on a rooted AVF-enabled device. If your device is attached over ADB, you can run:
cat > vm_config.json <<EOF { "kernel": "/data/local/tmp/kernel", "initrd": "/data/local/tmp/ramdisk", "params": "rdinit=/bin/init" } EOF adb root adb push <kernel> /data/local/tmp/kernel adb push <ramdisk> /data/local/tmp/ramdisk adb push vm_config.json /data/local/tmp/vm_config.json adb shell "/apex/com.android.virt/bin/vm run /data/local/tmp/vm_config.json"
The vm command also has other subcommands for debugging; run /apex/com.android.virt/bin/vm help for details.
To run OSes with graphics support, follow the instruction below.
As of today (April 2024), ChromiumOS is the only officially supported guest payload. We will be adding more OSes in the future.
First, check out source code from the ChromiumOS and Chromium projects.
Important: When you are at the step “Set up gclient args” in the Chromium checkout instruction, configure .gclient as follows.
$ cat ~/chromium/.gclient
solutions = [
{
"name": "src",
"url": "https://chromium.googlesource.com/chromium/src.git",
"managed": False,
"custom_deps": {},
"custom_vars": {
"checkout_src_internal": True,
},
},
]
target_os = ['chromeos']
In this doc, it is assumed that ChromiumOS is checked out at ~/chromiumos and Chromium is at ~/chromium. If you downloaded to different places, you can create symlinks.
Then enter into the cros sdk.
$ cd ~/chromiumos $ cros_sdk --chrome-root=$(readlink -f ~/chromium)
Now you are in the cros sdk. (cr) below means that the commands should be executed inside the sdk.
First, choose the target board. ferrochrome is the name of the virtual board for AVF-compatible VM.
(cr) setup_board --board=ferrochrome
Then, tell the cros sdk that you want to build chrome (the browser) from the local checkout and also with your local modifications instead of prebuilts.
(cr) CHROME_ORIGIN=LOCAL_SOURCE (cr) ACCEPT_LICENSES='*' (cr) cros workon -b ferrochrome start \ chromeos-base/chromeos-chrome \ chromeos-base/chrome-icu (cr) cros_workon_make --board ferrochrome chromeos-chrome
Optionally, if you have touched the kernel source code (which is under ~/chromiumos/src/third_party/kernel/v5.15), you have to tell the cros sdk that you want it also to be built from the modified source code, not from the official HEAD.
(cr) cros workon -b ferrochrome start chromeos-kernel-5_15
Finally, build individual packages, and build the disk image out of the packages.
(cr) cros build-packages --board=ferrochrome --chromium --accept-licenses='*' (cr) cros build-image --board=ferrochrome --no-enable-rootfs-verification test
This takes some time. When the build is done, exit from the sdk.
Note: If build-packages doesn’t seem to include your local changes, try invoking emerge directly:
(cr) emerge-ferrochrome -av chromeos-base/chromeos-chrome
Don’t forget to call build-image afterwards.
You need two outputs:
Push the kernel and the main image to the Android device.
$ adb push ~/chromiumos/src/build/images/ferrochrome/latest/chromiumos_test_image.bin /data/local/tmp/ $ adb push ~/chromiumos/out/build/ferrochrome/boot/vmlinuz /data/local/tmp/kernel
Create a VM config file as below.
$ cat > vm_config.json; adb push vm_config.json /data/local/tmp
{
"name": "cros",
"kernel": "/data/local/tmp/kernel",
"disks": [
{
"image": "/data/local/tmp/chromiumos_test_image.bin",
"partitions": [],
"writable": true
}
],
"params": "root=/dev/vda3 rootwait noinitrd ro enforcing=0 cros_debug cros_secure",
"protected": false,
"cpu_topology": "match_host",
"platform_version": "~1.0",
"memory_mib" : 8096
}
First, enable the VmLauncherApp app. This needs to be done only once. In the future, this step won't be necesssary.
$ adb root $ adb shell pm enable com.android.virtualization.vmlauncher/.MainActivity $ adb unroot
Then execute the below to set up the network. In the future, this step won't be necessary.
$ cat > setup_network.sh; adb push setup_network.sh /data/local/tmp
#!/system/bin/sh
set -e
TAP_IFACE=crosvm_tap
TAP_ADDR=192.168.1.1
TAP_NET=192.168.1.0
function setup_network() {
local WAN_IFACE=$(ip route get 8.8.8.8 2> /dev/null | awk -- '{printf $5}')
if [ "${WAN_IFACE}" == "" ]; then
echo "No network. Connect to a WiFi network and start again"
return 1
fi
if ip link show ${TAP_IFACE} &> /dev/null ; then
echo "TAP interface ${TAP_IFACE} already exists"
return 1
fi
ip tuntap add mode tap group virtualmachine vnet_hdr ${TAP_IFACE}
ip addr add ${TAP_ADDR}/24 dev ${TAP_IFACE}
ip link set ${TAP_IFACE} up
ip rule flush
ip rule add from all lookup ${WAN_IFACE}
ip route add ${TAP_NET}/24 dev ${TAP_IFACE} table ${WAN_IFACE}
sysctl net.ipv4.ip_forward=1
iptables -t filter -F
iptables -t nat -A POSTROUTING -s ${TAP_NET}/24 -j MASQUERADE
}
function setup_if_necessary() {
if [ "$(getprop ro.crosvm.network.setup.done)" == 1 ]; then
return
fi
echo "Setting up..."
check_privilege
setup_network
setenforce 0
chmod 666 /dev/tun
setprop ro.crosvm.network.setup.done 1
}
function check_privilege() {
if [ "$(id -u)" -ne 0 ]; then
echo "Run 'adb root' first"
return 1
fi
}
setup_if_necessary
^D
adb root; adb shell /data/local/tmp/setup_network.sh
Then, finally tap the VmLauncherApp app from the launcher UI. You will see Ferrochrome booting!
If it doesn’t work well, try
$ adb shell pm clear com.android.virtualization.vmlauncher
Go to the network setting and configure as below.
These settings are persistent; stored in chromiumos_test_image.bin. So you don’t have to repeat this next time.`