qemu ram size

在cat /proc/meminfo下 ram總是90多MB
看了一下 qemu的source
原來是在 externel/qemu/android/avd/hardware-properties.ini 設定的
default是 96MB

Android webkit裡的GIF Animation

大家一直在吵說android的webkit到底有沒有support animate GIF
有的人說有 有的人說沒有

雖然在config.h 裡  是有define ANDROID_ANIMATED_GIF
但其實關鍵是在ANDROID_LARGE_MEMORY_DEVICE

而這個option只有在比較後面的device 才有enable, 像nexus one
http://android.git.kernel.org/?p=platform/external/webkit.git;a=blob;f=Android.mk;h=21f6cf4e8b7d65479cbeb741f63a17b2d94f8238;hb=HEAD#l242


而android emulator上  並不會enable這個option
參考
http://allstarschh.blogspot.com/2010/11/default-javascript-engine-on-froyo.html

所以就目前Android  2.3上只有在device上才能看到animated GIF emulator上不行

如果一定想要在emulator上跑的話
就要自己enable ANDROID_LARGE_MEMORY_DEVICE 這個option了

the default Javascript engine on froyo emulator

大家都以為到了froyo, Webkit就default 使用 V8 來作javascript engine了

但其實在emulator裡 還是使用 JavascriptCore來作JavaScript engine

先看
http://android.git.kernel.org/?p=platform/external/webkit.git;a=blob;f=Android.mk;h=4390cf32121dc7de380b8d1fc655c48228e4e502;hb=HEAD#l48
要在 ARCH_ARM_HAVE_VFP 有被defined時  default js engine才是v8

emulator default是用armv5-te的cpu
http://android.git.kernel.org/?p=platform/build.git;a=blob;f=core/combo/TARGET_linux-arm.mk;h=f998cf44b7f7e6eebafefa97500cae12c0bf57d2;hb=HEAD#l34

而armv5-te的makefile裡 並沒有enable ARCH_ARM_HAVE_VFP
http://android.git.kernel.org/?p=platform/build.git;a=blob;f=core/combo/arch/arm/armv5te.mk;h=29aada6d9c52d08a3d8b7c4fac46d78f5b99f694;hb=HEAD

在這個post裡說明了為什麼emulator 還是用armv5而不是用armv7
http://groups.google.com/group/android-ndk/browse_thread/thread/a19fc6df3d661d79/b063b388744fa0ee?hl=en&lnk=gst&q=armv7#b063b388744fa0ee

android emulator support

SMS
    - external/qemu/telephony/modem_driver.c
    see http://developer.android.com/guide/developing/tools/emulator.html#sms for usage

MMS
    - N/A

Geolocation/GPS
    - external/qemu/android/gps.[c|h]

    - how to set
        - ddms :
            Emulator Control -> Location Controls -> {Manual, GPX, KML}

        - shell:
            $>telnet localhost
            gps fix
      
Sensor
    emulator has defined 4 sensors
    - acceleration
    - magnetic_field
    - orientation
    - temperature
    only accelerometer is enable, others need to be tested
    see external/qemu/android/hw-sensors.[c|h]
        external/qemu/android/avd/hardware-properties.ini
    for the changing orientation in emulator( Ctrl + F11),
    Android framework computes the orientation by looking at the accelerometer
    see external/qemu/android/hw-sensors.c _hwSensors_setCoarseOrientation

    for the measure units, see hardware/libhardware/include/hardware/sensors.h
  
Camera
    it forks a preview thread, and keeps generating a YUV422 SurfaceView

    see
    - frameworks/base/camera/libcameraservice/FakeCameara.[cpp|h]
    - frameworks/base/camera/libcameraservice/CameraHardwareStub.[cpp|h]
    to modify it to generate different preview screen


Vibration
    not implemented in emulator
    external/qemu/android/hw-control.c # hw_control_do_query only handles power:light:brightness
    and see /sys/class/timed_output/vibrator/enable on device

Backlight
    - external/qemu/android/hw-control.c

    there are 3 kinds of backlight:
        - lcd_backlight
        - keyboard_backlight
        - button_backlight
    but 'Documents' says only lcd_backlight is supported
    see extenal/qemu/docs/ANDROID-QEMUD-SERVICES.TXT #hw-control services

    but actually even lcd_backlight can not work
    because hardware module 'LIGHTS_HARDWARE_MODULE_ID' is only available when
    TARGET_BOARD_PLATFORM is msm7k or qsd8k_dirs
    see hardware/
  
    also see /sys/class/leds on device

Battery Level
    the implementation is in external/qemu/hw/goldfish_battery.c
    - adb shell dumpsys battery

    also it will create a file /sys/class/power_supply/battery on device

Signal Strength
    the implementation is in external/qemu/telephony/android_modem.c
    see the line
    '{ "+CSQ", "+CSQ: 7,99", NULL },  /* XXX: TODO: implement variable signal strength and error rates */'
    modify 7 to change to signal strength

CPU frequency
    N/A
    but we can get cpu usage by issuing adb
    - adb shell dumpsys cpuinfo

    before cupcake, in Development.apk, there's a option for displaying cpu usage on screen,
    but this isn't supported anymore
    see frameworks/base/libs/surfaceflinger/SurfaceFlinger.cpp  #SurfaceFlinger::onTransact

android emulator的cpu

http://groups.google.com/group/android-ndk/browse_thread/thread/b41d13b517abe69d?hl=en



不知道中間Dave Buther講的這段話
On the emulator I suspect it is being (correctly) treated as an
UNDEFINED instruction (the emulator is running as an ARM926 I
believe), under user-mode on an ARM1176 or an ARMv7-a processor it
will still be treated as an UNDEFINED
while in user mode. 


是什麼意思............

mydroid 找不到sdcard

今天發現我從mydroid build出來的emulator一直mount 不到sdcard

最後發現 我的 /etc/沒有 vold.conf這檔案

然後就把 mydroid/development/data/etc/vold.conf  copy 到
out/target/product/generic/system/etc下
然後make systemimage 

我可以mount到sdcard了!!!

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在Android emulator 上改userdata system 的image max size

之前被問到userdata image要如何改大小

花了很多時間才找到XD

首先從Android build system講起
在mydroid/build/core/definitions.mk裡
有個
define assert-max-file-size的 function
原本以為只要指定
BOARD_FLASH_BLOCK_SIZE 跟BOARD_USERDATAIMAGE_MAX_SIZE
就可以了
但發現他這只是作個檢查的動作而已

不過他這有講到 /proc/mtd的東西
然後看了其他的code
也都是去讀 /proc/mtd 來作partition

dev: size erasesize name
mtd0: 04000000 00020000 "system"
mtd1: 04000000 00020000 "userdata"
mtd2: 04000000 00020000 "cache

然後去checkout android linux kernel的code
下載完首先要switch 到有goldfish的branch
不然預設是msm 裡面沒有goldfish的driver 編kernel也會有error
會跳到linux kernel裡面看的原因是有的embedded linux
會把mtd 的size name 等的information寫在 /drivers/mtd/map下
一個叫mtd_parition的struct裡


在drivers/mtd/devices/goldfish_nand.c下 有看到設定size的code
但他也是從memory中讀值出來而已
static int goldfish_nand_init_device(struct goldfish_nand *nand, int id)
看mtd->size
但是其他的地方都找不到設定size的地方

後來又跳到emulator的source裡看(mydroid/external/qemu)
首先發現了qemu可以讓你指定nand
"-nand name[,readonly][,size=size][,pagesize=size][,extrasize=size][,erasepages=pages][,initfile=file][,file=file]"

然後發現
android在emulator的options裡有加讓你設定nand size的option
-partition-size system/data partition size in MBs


所以 結論就是
在emulator後面加上 -partition-size 就可以設定system userdata image的大小了

# cat /proc/mtd
dev: size erasesize name
mtd0: 07c20000 00020000 "system"
mtd1: 07c20000 00020000 "userdata"
mtd2: 04000000 00020000 "cache"