1. Tweaking Google TV emulator
2011.8.28
Tetsuyuki Kobayashi
1

2. Who am I?
 20+ years involved in embedded systems
 10 years in real time OS, such as iTRON
 10 years in embedded Java Virtual Machine
 Now GCC, Linux, QEMU, Android, …
 Blogs
 http://d.hatena.ne.jp/embedded/ (Personal)
 http://blog.kmckk.com/ (Corporate)
 http://kobablog.wordpress.com/(English)
 Twitter
 @tetsu_koba
2

3. Today's topic
 Google TV add-on
 What is KVM?
 Tweaking Google TV emulator
 Why NDK doesn't work?
 How to run it on Windows 7
3

4. Google TV add-on
 Add-on for Android SDK to
develop Google TV apps.
 http://code.google.com/tv/android/docs/gtv_addon.html
 Existing Java apps can run on it,
but need modification for TV UI.
 Display Guidelines, UI Control
Guidelines
4

5. From FAQ, Google TV version 2 is ...
 Android 3.1.
 NDK is not currently supported
 Chrome 11 (OTA upgradeable)
 Flash 10.1
 Native client app support is not
currently available.
 continue to support the h.264 video
codec for the HTML5 <video> tag. 5

6. Google TV emulator
 Target CPU is x86 (ATOM)
 KVM required
 It means only Linux
 Windows and Mac is currently
not supported
 Open GL rendering by software
 Not accelerated by GPU
6

7. What is KVM?
 Kernel Based Virtual Machine
 Host OS: x86 Linux, with Intel VT
or AMD-V
 Guest CPU must be the same as
host CPU
 used with QEMU
 http://www.linux-kvm.org/page/Main_Page
7

8. How it works
 Usual QEMU
 emulates all instructions.
 MMU is emulated by software,
too.
 QEMU + KVM
 mostly executed by real CPU.
 hooks only I/O instructions.
8

9. Setup KVM
 On Ubuntu
 $ sudo apt-get install kvm
 On Ubuntu 10.04
 $ sudo chmod a+rw /dev/kvm
(On Ubuntu 11.04 it worked
without this)
 See also
9
 http://code.google.com/tv/android/docs/gtv_emulator.html

10. Comparison by boot up time
Ubuntu 10.04 KVM Off
52
Ubuntu 10.04 KVM On 32
Ubuntu 11.04 KVM Off
52
Ubuntu 11.04 KVM On
17
0 10 20 30 40 50 60
(Smaller is better)
KVM is tuning up. Newer version is faster! 10

11. Tweaking Google TV emulator
 Why NDK doesn't work?
 How to run it on Windows 7
11

12. NDK for x86
 NDKr6 supports x86
 You can build x86 emulator and
Android image from AOSP source
code
 NDK for x86 works fine in this
environment
12

13. But it doesn't work in Google TV.
Why?
 Google TV runtime is different
from Android.
 Dynamic linker and libc is not
bionic's, it seems to be glibc's.
 NDK r6 assumes bionic runtime.
13

14. Zygote maps in Android
…
afa00000-afa03000 r-xp 00000000 1f:00 380 /system/lib/liblog.so
afa03000-afa04000 rwxp 00003000 1f:00 380 /system/lib/liblog.so
afb00000-afb20000 r-xp 00000000 1f:00 348 /system/lib/libm.so
afb20000-afb21000 rwxp 00020000 1f:00 348 /system/lib/libm.so
afc00000-afc01000 r-xp 00000000 1f:00 326 /system/lib/libstdc++.so
afc01000-afc02000 rwxp 00001000 1f:00 326 /system/lib/libstdc++.so
afd00000-afd40000 r-xp 00000000 1f:00 351 /system/lib/libc.so
afd40000-afd43000 rwxp 00040000 1f:00 351 /system/lib/libc.so
afd43000-afd4e000 rwxp afd43000 00:00 0
b0001000-b0009000 r-xp 00001000 1f:00 606 /system/bin/linker
b0009000-b000a000 rwxp 00009000 1f:00 606 /system/bin/linker
b000a000-b0013000 rwxp b000a000 00:00 0
bedaa000-bedbf000 rw-p befeb000 00:00 0 [stack]
14

15. Zygote maps in Google TV
b7544000-b7699000 r-xp 00000000 00:01 44 /lib/libc-2.12.2.so
b7699000-b769b000 r--p 00155000 00:01 44 /lib/libc-2.12.2.so
b769b000-b769c000 rw-p 00157000 00:01 44 /lib/libc-2.12.2.so
b769c000-b769f000 rw-p 00000000 00:00 0
b769f000-b76c2000 r-xp 00000000 00:01 51 /lib/libm-2.12.2.so
b76c2000-b76c3000 r--p 00023000 00:01 51 /lib/libm-2.12.2.so
b76c3000-b76c4000 rw-p 00024000 00:01 51 /lib/libm-2.12.2.so
...
b7879000-b787d000 r-xp 00000000 1f:00 469 /system/lib/liblog.so
b787d000-b787e000 rw-p 00003000 1f:00 469 /system/lib/liblog.so
b787e000-b7896000 r-xp 00000000 00:01 61 /lib/libpthread-2.12.2.so
b7896000-b7897000 ---p 00018000 00:01 61 /lib/libpthread-2.12.2.so
b7897000-b7898000 r--p 00018000 00:01 61 /lib/libpthread-2.12.2.so
b7898000-b7899000 rw-p 00019000 00:01 61 /lib/libpthread-2.12.2.so
b7899000-b789b000 rw-p 00000000 00:00 0
...
b78ac000-b78ad000 r-xp 00000000 00:00 0 [vdso]
b78ad000-b78c9000 r-xp 00000000 00:01 42 /lib/ld-2.12.2.so
b78c9000-b78ca000 r--p 0001b000 00:01 42 /lib/ld-2.12.2.so
b78ca000-b78cb000 rw-p 0001c000 00:01 42 /lib/ld-2.12.2.so
bfdda000-bfdfb000 rw-p 00000000 00:00 0 [stack]
15

16. How to run Google TV emulator
on Windows7
 Yes, KVM is tightly coupled with
Linux.
 But without KVM, does it work on
Windows or Mac?
16

17. Elements of Google TV emulator
 (1) Emulator executable (using
QEMU + KVM)
 (2) Image of target Linux kernel
 (3) Images of target file system
 (4) Skin image files
 AVD files configure (1)-(4).
 Only (1) depends on host OS. 17

18. Let's try
 Android SDK for windows already
have emulator-x86.exe
 Copy the reset files from Linux
 $SDK/add-ons/addon_google_tv_google_inc_12
 $HOMEPATH/.android/avd/<avd>.ini
 $HOMEPATH/.android/avd/<avd>.avd
 Correct file path in each *.ini files
18

19. Start Google TV emulator on
Windows
 Start the emulator with the copied
avd from command prompt
 emulator -avd <avd>
 It worked!
 But too slow to use!
 I understand how emulator works!
19

20. Resources
 Previous Google TV session by @kisima
 http://d.hatena.ne.jp/machaut/20110213/1297613974
 KVM session at 1st KernelVM 探検隊
 http://www.slideshare.net/ozax86/linux-kvm
 How to build emulator-x86
 http://d.hatena.ne.jp/embedded/20110710/p1
 How to build linux kernel for emulator-x86
 http://blog.kmckk.com/archives/3882660.html
20

21. Demo / Q & A
Thank you for listening!
Any comments to blogs are welcome.
@tetsu_koba
21