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Andriod

Android is a kind of Linux with google magic

  • termux - an Android terminal emulator and Linux environment app
  • scrcpy - "screen copy" mirrors Android devices
    • scrcpy desktop
  • waydriod - android container

https://gs.statcounter.com/os-market-share

https://gs.statcounter.com/os-market-share

Android parts

  • Android 啟動過程 - init 進程 https://hackmd.io/pJpAeKAeRea0VIW3oI-mXw?view
    • https://hackmd.io/@AlienHackMd/BkvyAzNf9
  • The Generic Kernel Image (GKI) project
    • kernel module interface (KMI)
  • bionic libc (native part) - ndk
    • BSD license / Small size / Speed
  • android runtime (java part) - sdk
  • adb (android debug bridge) shell

termux

https://pbs.twimg.com/media/EeDRB0aX0AMj5kh

  • termux-emulator
    • with function key keyboard
    • as desktop via scrcpy
  • Linux environment
    • as personal edge server
      • with multi-sensors / phone functions
        • termux-api
      • androud call termux
        • termux-tasker
      • near 24/7 online
    • powerful device
      • gpu https://blog.csdn.net/Billhe_zju/article/details/122706171
    • docker / podman container (not real ready)
      • run in qemu
      • podman machine (not yet)
      • native docker/podman/lxc (need root)
      • (-) as kubeedge node
  • install from github or f-driod (*)

Termux Google Play

https://wiki.termux.com/wiki/Termux_Google_Play https://github.com/termux/termux-app/issues/1072

  • If Termux application was built with target SDK level "29" (Android 10) or higher, it will be eligible for SELinux restriction of execve() system call on data files.
  • That makes impossible to run package executables such as "apt", "bash" and others located in the application's writable directory such as $PREFIX.

termux application (main parts)

  • single user
  • native (bionic libc)
  • terminal-emulator
  • terminal-shared
    • shell
    • socket
    • am (Activity Manager)
    • notification
  • limited kernel function (w/o root)
  • termux file system layout
    • https://github.com/termux/termux-packages/wiki/Termux-file-system-layout

Termux Addons

https://wiki.termux.com/wiki/Addons

  • Termux:API
    • Access Android and Chrome hardware features.
  • Termux:Boot
    • Run script(s) when your device boots.
  • Termux:Float
    • Run Termux in a floating window.
  • Termux:Styling
    • Have color schemes and powerline-ready fonts customize the appearance of the Termux terminal.
  • Termux:Tasker
    • An easy way to call Termux executables from Tasker and compatible apps.
  • Termux:Widget
    • Start small scriptlets from the home screen.

termux fs layout
- Root directory/data/data/com.termux/files/usr ${TERMUX_PREFIX}
${TERMUX_PREFIX}/binExecutables used by shell. Combines /bin, /sbin, /usr/bin, /usr/sbin.*
${TERMUX_PREFIX}/etcConfiguration files.
${TERMUX_PREFIX}/includeheaders
${TERMUX_PREFIX}/libShared objects (libraries)
${TERMUX_PREFIX}/libexecExecutables which should not be run by user directly.
${TERMUX_PREFIX}/optInstallation root for sideloaded packages.
${TERMUX_PREFIX}/shareNon-executable runtime data and documentation.
${TERMUX_PREFIX}/tmpTemporary files. Combines /tmp and /var/tmp. Can be freely modified by user.
${TERMUX_PREFIX}/varsuch as caches and databases. Can be modified by user, but with additional care.
${TERMUX_PREFIX}/var/runLock, PID, sockets and other temporary files created by daemons. Replaces /run.
- Home directory/data/data/com.termux/files/home ${HOME}

termux packages

  • format - binary deb packages
    • package manager: pkg / apt
  • single source repo: https://github.com/termux/termux-packages
  • native (bionic libc)
  • repos / mirrors:
    • termux
    • termux-root
    • termux-x11
    • tut (others)

edge server

  • termux-service / runit
    • https://github.com/termux/termux-services
    • SVDIR: /data/data/com.termux/files/usr/var/service
    • $ tail -f ../usr/var/log/sv/sshd/current
  • termux-boot
    • https://github.com/termux/termux-boot
    • allowing programs to be run at boot.
  • termux-wake-lock

termux useful services

  • ngrok - Ingress Platform
  • ssh
    • single user / id
    • disbale password login
  • openvpn (via android app)

cli / tui - old school but awesome

  • colorful
  • auto complete
  • animation
  • cli / tui framework
  • http config

termux-setup-storage

https://wiki.termux.com/wiki/Internal_and_external_storage

Executing termux-setup-storage ensures:

That permission to shared storage is granted to Termux when running on Android 6.0 or later. That an app-private folder on external storage is created (if external storage exists). That a folder $HOME/storage is created.

proot: An chroot-like implementation using ptrace.

  • General usage information
    • unset LD_PRELOAD - Termux-exec, execve() hook, conflicts with PRoot.
    • -r ./rootfs - option to specify the rootfs where Linux distribution was installed.
    • -0 - tells PRoot to simulate a root user which expected to be always available in Linux distributions. This option will allow you to use package manager.
    • -b /dev -b /proc -b /sys - make file systems at /dev, /proc, /sys appear in the rootfs. These 3 bindings are important and used by variety of utilities.
    • /bin/sh - a program that should be executed inside the rootfs. Typically a shell.
  • other forks
    • AnLinux
    • UserLand

proot-disto git@github.com:termux/proot-distro.git

proot-distro install debian
proot-distro login debian

`

  • ubuntu / redhat
  • nix

qemu

qemu-system-aarch64-headless

termux api

  • termux-sms-send

$ termux-battery-status

{
  "health": "GOOD",
  "percentage": 27,
  "plugged": "UNPLUGGED",
  "status": "DISCHARGING",
  "temperature": 35.099998474121094,
  "current": -1780000
}

GUI

Termux:GUI

  • Official
    • Python
    • C/C++
    • Bash
  • Community
    • Rust

https://github.com/termux/termux-gui

  • enables command line programs to use the native android GUI.

Termux:x11

  • A Termux X11 server add-on app.

https://github.com/termux/termux-x11

termux am

  • https://github.com/termux/TermuxAm
  • https://github.com/termux/termux-am-socket

build app in termux

https://sdrausty.github.io/docsBuildAPKs/ https://gist.github.com/tmatz/817bf03433e059bf89c63dc33f286ccb

https://wiki.termux.com/wiki/Development_Environments

termux-rust / android rust

Tier 2 with Host Tools

Tier 2 without Host Tools

  • aarch64-linux-android
  • x86_64-linux-android

https://doc.rust-lang.org/nightly/rustc/platform-support.html https://doc.rust-lang.org/nightly/rustc/platform-support/android.html https://www.youtube.com/watch?v=gUz4thxBuTs https://android.googlesource.com/toolchain/android_rust/

termux-docker

  • kind of
docker run -it termux/termux-docker:latest

docker run --rm --privileged aptman/qus -s -- -p aarch64 arm

docker run -it --privileged termux/termux-docker:aarch64

https://github.com/termux/termux-docker/blob/master/Dockerfile

FROM scratch AS bootstrap
...
ADD https://github.com/termux/termux-packages/releases/download/bootstrap-$BOOTSTRAP_VERSION/bootstrap-$BOOTSTRAP_ARCH.zip /bootstrap.zip

scrcpy

  • audio forwarding (Android 11+)
  • recording
  • mirroring with Android device screen off
  • copy-paste in both directions
  • configurable quality
  • camera mirroring (Android 12+)
  • mirroring as a webcam (V4L2) (Linux-only)
  • physical keyboard and mouse simulation (HID)
  • OTG mode
  • and more…

android desktop

  • samsung dex / moto ready for

    • Linux on DeX (dead)

  • desktop mode / android 15

  • desktop launcher

    • Taskbar
    • https://github.com/axel358/smartdock

scrcpy-desktop

  • https://github.com/nikp123/scrcpy-desktop

  • adb shell settings put global overlay_display_devices $TARGET_DISPLAY_MODE

  • scrcpy --display-id $display -w -S -K &

waydroid

  • Waydroid uses Linux namespaces to run a full Android system in a container (LXC) on any GNU/Linux-based platform.
  • The Android inside the container has direct access to the needed hardware.

Happy Hacking All Your Linux Devices

Thank you