Waydroid@ULFS/0.2.4

Research project aimed to port Waydroid to Umvirt Linux From Scratch 0.2.4.

Installation

1. Install and enable LightDM (if not installed)

    chimp install lightdm
    cd /usr/share/blfs-systemd-units
    make install-lightdm

2. Install weston

    chimp install weston

3. Install waydroid

    chimp install waydroid

4. Install Android images

Get "*-vendor.zip" and "*-system.zip" files with same prefixes and unpack it.

Copy "vendor.img" and "system.img" files to "/usr/share/waydroid-extra/images" directory.

Note: At first try "lineage-20.0-20250809-MAINLINE-waydroid_x86_64-vendor.zip" and "lineage-20.0-20250809-VANILLA-waydroid_x86_64-system.zip". Then try other versions.

5. Kernel configuration check

To check current Linux kernel configuration ulfs-kernel-config-checker can be used.

Clone ulfs-kernel-config-checker

    git clone https://gitlab.com/Umvirt/ulfs-kernel-config-checker

Build it

    cd ulfs-kernel-config-checker
    make

Create link to current kernel config file

    ln -s /usr/src/linux-6.16.1/.config config/config

At first check that current config is pass ULFS checks

    ./checkall amd64

If some checks failed you can fix configuration manually or use sample kernel config file "waydroid.config" shipped with Waydroid package.

File "waydroid.config" is failed some ULFS checks but works fine with Waydroid.

Then check current config for Waydroid support

    ./checker amd64-extra waydroid

You have to pass all checks:

CHECK: Waydroid kernel support

OK        CONFIG_BLK_DEV_LOOP                     y                   m/y                                     
OK        CONFIG_ANDROID_BINDER_DEVICES           binder,hwbinder,vndbinderbinder,hwbinder,vndbinder               
OK        CONFIG_NETFILTER_XT_TARGET_CHECKSUM     m                   m/y                                     
OK        CONFIG_ANDROID_BINDER_IPC               y                   m/y                                     
OK        CONFIG_NF_CT_NETLINK                    y                   y                                       
OK        CONFIG_ANDROID_BINDERFS                 NULL                NULL                                    
OK        CONFIG_PSI                              y                   y                                       
OK        CONFIG_VETH                             y                   y

6. Linux kernel preparation

There are two options to make Linux kernel ready to run Waydroid:

Build kernel using reference config file.
Build kernel with modified current config file.

6.a Using reference config

Waydroid package is shipped with reference kernel config which known to work with Waydroid.

This option is rewrite current configuration.

Warrning: If you wish to keep current configuration drivers and settings you have to edit your configuration and use it.

Just copy %waydroid_kernel% to linux kernel directory (/usr/src/linux-6.16.1)

    cp -v /sources/waydroid.config /usr/src/linux-6.16.1/.config

6.b Kernel configuration file edit

Go to linux kernel directory.

    cd /usr/src/linux-6.16.1

To edit kernel file use command

    make menuconfig

Also other editors is available. Check Linux kernel documentation.

7. Kernel building and installing

Before building check that kernel config is configured correctly. This saves a time consumed by building and debugging.

Go to linux kernel directory.

    cd /usr/src/linux-6.16.1

Build and install kernel

    chimp kernel_build

Install kernel

    chimp kernel_install

8. Reboot system

    reboot

System configuration

Create unpriveleged user to run Waydroid if not created

    useradd -U -m user

Add dbus support to Weston session

Open file "weston.desktop" file in "/usr/share/wayland-sessions". Replace

    Exec=weston

    Exec=dbus-launch weston

Fix pulseaudio idle issues

Edit pulseaudio config (as root)

Open "/etc/pulse/daemon.conf" file. Replace
```
;exit-idle-time = 20
```

    exit-idle-time = -1

Open "/etc/pulse/system.pa" file. Comment or delete line
```
load-module module-suspend-on-idle
```

Waydroid config

Check that vendor.img and system.img is located in /usr/share/waydroid-extra/images
```
ls /usr/share/waydroid-extra/images
```
Init waydroid LXC container
```
waydroid init -f
```

Enable and run waydroid service

systemctl enable waydroid-container
systemctl start waydroid-container

    systemctl enable --now waydroid-container

tip: To check waydroid-container status (as root) type

    systemctl status waydroid-container

Check that memfd module for waydroid container is enabled in "/var/lib/waydroid/waydroid_base.prop" file

    cat /var/lib/waydroid/waydroid_base.prop | grep memfd

You should get

    sys.use_memfd=true

Create file "org.freedesktop.Notifications.service" in "/usr/share/dbus-1/services" directory:

cat > /usr/share/dbus-1/services/org.freedesktop.Notifications.service << "EOF"
[D-BUS Service]
Name=org.freedesktop.Notifications
Exec=/usr/libexec/notification-daemon
EOF

Software rendering is needed to launch Waydroid in Virtual Machines. To enable software rendering open "/var/lib/waydroid/waydroid.cfg" file and add
```
ro.hardware.gralloc=default
ro.hardware.egl=swiftshader
```

in "properties" section (end of file).