Controlling the Android Emulator and Virtual Devices (AVDs) via the command-line

I Googled all around to try and figure out how to tweak Android Emulator virtual devices (AVDs) via the command-line.  The Android Emulator documentation online has some options for running the emulator, but it didn’t allow me to specify memory at runtime, and many other things I wanted to customize.  There is also documentation specific to the creation of AVDs (vs just the running of them on the emulator), but that kept referring to the UI tools for it. I’ve gotten so used to Googling for help, that I didn’t think of running help locally :-p

emulator -help

That gives us a LOT of options that are not documented on the website including.

Android Emulator usage: emulator [options] [-qemu args]
    -list-avds                     list available AVDs
    -sysdir <dir>                  search for system disk images in <dir>
    -system <file>                 read initial system image from <file>
    -writable-system               make system image writable after 'adb remount'
    -datadir <dir>                 write user data into <dir>
    -kernel <file>                 use specific emulated kernel
    -ramdisk <file>                ramdisk image (default <system>/ramdisk.img
    -image <file>                  obsolete, use -system <file> instead
    -initdata <file>               same as '-init-data <file>'
    -data <file>                   data image (default <datadir>/userdata-qemu.img
    -partition-size <size>         system/data partition size in MBs
    -cache <file>                  cache partition image (default is temporary file)
    -cache-size <size>             cache partition size in MBs
    -no-cache                      disable the cache partition
    -nocache                       same as -no-cache
    -sdcard <file>                 SD card image (default <system>/sdcard.img
    -snapstorage <file>            file that contains all state snapshots (default <datadir>/snapshots.img)
    -no-snapstorage                do not mount a snapshot storage file (this disables all snapshot functionality)
    -snapshot <name>               name of snapshot within storage file for auto-start and auto-save (default 'default-boot')
    -no-snapshot                   perform a full boot and do not do not auto-save, but qemu vmload and vmsave operate on snapstorage
    -no-snapshot-save              do not auto-save to snapshot on exit: abandon changed state
    -no-snapshot-load              do not auto-start from snapshot: perform a full boot
    -snapshot-list                 show a list of available snapshots
    -no-snapshot-update-time       do not do try to correct snapshot time on restore
    -wipe-data                     reset the user data image (copy it from initdata)
    -avd <name>                    use a specific android virtual device
    -skindir <dir>                 search skins in <dir> (default <system>/skins)
    -skin <name>                   select a given skin
    -no-skin                       don't use any emulator skin
    -noskin                        same as -no-skin
    -dynamic-skin                  dynamically construct a skin of given size, requires -skin WxH option
    -memory <size>                 physical RAM size in MBs
    -accel <mode>                  Configure emulation acceleration
    -no-accel                      Same as '-accel off'
    -ranchu                        Use new emulator backend instead of the classic one
    -engine <engine>               Select engine. auto|classic|qemu2
    -netspeed <speed>              maximum network download/upload speeds
    -netdelay <delay>              network latency emulation
    -netfast                       disable network shaping
    -code-profile <name>           enable code profiling
    -show-kernel                   display kernel messages
    -shell                         enable root shell on current terminal
    -no-jni                        disable JNI checks in the Dalvik runtime
    -nojni                         same as -no-jni
    -logcat <tags>                 enable logcat output with given tags
    -no-audio                      disable audio support
    -noaudio                       same as -no-audio
    -audio <backend>               use specific audio backend
    -raw-keys                      disable Unicode keyboard reverse-mapping
    -radio <device>                redirect radio modem interface to character device
    -port <port>                   TCP port that will be used for the console
    -ports <consoleport>,<adbport> TCP ports used for the console and adb bridge
    -onion <image>                 use overlay PNG image over screen
    -onion-alpha <%age>            specify onion-skin translucency
    -onion-rotation 0|1|2|3        specify onion-skin rotation
    -dpi-device <dpi>              specify device's resolution in dpi (default 165)
    -scale <scale>                 scale emulator window (deprecated)
    -http-proxy <proxy>            make TCP connections through a HTTP/HTTPS proxy
    -timezone <timezone>           use this timezone instead of the host's default
    -dns-server <servers>          use this DNS server(s) in the emulated system
    -cpu-delay <cpudelay>          throttle CPU emulation
    -no-boot-anim                  disable animation for faster boot
    -no-window                     disable graphical window display
    -version                       display emulator version number
    -report-console <socket>       report console port to remote socket
    -gps <device>                  redirect NMEA GPS to character device
    -keyset <name>                 specify keyset file name
    -shell-serial <device>         specific character device for root shell
    -tcpdump <file>                capture network packets to file
    -bootchart <timeout>           enable bootcharting
    -charmap <file>                use specific key character map
    -prop <name>=<value>           set system property on boot
    -shared-net-id <number>        join the shared network, using IP address 10.1.2.<number>
    -nand-limits <nlimits>         enforce NAND/Flash read/write thresholds
    -gpu <mode>                    set hardware OpenGLES emulation mode
    -camera-back <mode>            set emulation mode for a camera facing back
    -camera-front <mode>           set emulation mode for a camera facing front
    -webcam-list                   lists web cameras available for emulation
    -screen <mode>                 set emulated screen mode
    -force-32bit                   always use 32-bit emulator
    -selinux <disabled|permissive> Set SELinux to either disabled or permissive mode

     -qemu args...                 pass arguments to qemu
     -qemu -h                      display qemu help

     -verbose                      same as '-debug-init'
     -debug <tags>                 enable/disable debug messages
     -debug-<tag>                  enable specific debug messages
     -debug-no-<tag>               disable specific debug messages

     -help                         print this help
     -help-<option>                print option-specific help

     -help-disk-images             about disk images
     -help-keys                    supported key bindings
     -help-debug-tags              debug tags for -debug <tags>
     -help-char-devices            character <device> specification
     -help-environment             environment variables
     -help-keyset-file             key bindings configuration file
     -help-virtual-device          virtual device management
     -help-sdk-images              about disk images when using the SDK
     -help-build-images            about disk images when building Android
     -help-all                     prints all help content

I hope you found this from YOUR Google search about this, and it helped 🙂

Running Multiple Android Emulators Simultaneously on OSX

I had a long standing issue where I could only launch two emulators on my Macbook Pro simultaneously.  Any other emulators would launch and get a black screen and wouldn’t load.  I accepted this as fact, and carried on with life.


Finally today I found the need to figure out “why” this was the case as I wanted to start sharding my Android UI tests to speed them up.  I was given the suggestion that it could be the # of CPUs or the amount of RAM.  If you look in the logs you may see something like this (if you launch the emulator from android avd):


or you may see:

“HAXM does not have enough memory remaining to load this AVD.”

In order to change your memory allocation for HAXM, you need to re-install it, so run the installer again which is a DMG at: [$ANDROID_HOME/sdk/extras/intel/Hardware_Accelerated_Execution_Manager/ ] and this time select more memory. [HAXM Technical Docs]screen-shot-2016-09-07-at-8-27-05-pm

But… before you install, make sure you have the latest version. The latest version as of September 7th, 2016 is 6.0.3 (Which was released on June 21, 2016).

On my Macbook, I was given 2048MB of memory by default which allowed me to run 2 emulators simultaneously (as seen above).screen-shot-2016-09-07-at-6-58-46-pm

I have 16GB total memory though, so lets make it so I can run a bunch of emulators at once by allocating 8GB 🙂

Here is my Macbook Pro running 6 Android emulators simultaneously after the changes:

Success!!!  May the sharding begin!

Related Links:

Continuous Integration for Android Using Jenkins

Dan Jarvis and I co-presented a talk entitled “Continuous Integration for Android Using Jenkins” at the Android Summit 2016 on August 26, 2016 in McLean, Virginia.  Here are our slides.  Video should be available in the coming weeks and will be posted here and on Twitter.

Some Highlights:

  • Automate everything (If you can script it, do it)
  • “There’s an app for that” on a smartphone, “There’s a plugin for that” on Jenkins
  • The Android Emulator is great for scalability in CI, it’s fast and you can configure it in many ways
  • Shard for speed