[Galaxy Grand Duos i9082 General] The jOkEr!:
Hello fellow xda members. Today i present you my little tutorial about the build.prop file. I have taken the reference build.prop from k2wl's aokp rom.

Please make a nandroid backup in case something goes wrong.

I´m not responsible for any damages to your phone.

LETS BEGIN

This mentions that the build prop is built by build info shell script during the compilation of the ROM.

# begin build properties

# autogenerated by buildinfo.sh

Version name of 4.2.2(jellybean)

ro.build.id=JDQ39

Current rom version on phone

ro.build.display.id=aokp_i9082-userdebug 4.2.2 JDQ39 eng.k2wl.20130827.005402

Your current modem version

ro.build.version.incremental= eng.k2wl.20130827.005402

Current sdk version of framework plus codename

ro.build.version.sdk=17

ro.build.version.codename=REL

Current android version on phone

ro.build.version.release=4.2.2

This is the time and date of when the Kernel was built.

ro.build.date=Aug 27 00:54:58 IST 2013

Other Kernal Details

ro.build.date.utc=1377545098

ro.build.type=userdebug

ro.build.user=android-build

ro.build.host=k2wl-HP-EliteBook-8440p

Test keys means that the ROM is not an official version of the ROM. Release keys are for official releases.

ro.build.tags=release-keys

Model Number

ro.product.model=GT-I9082

Phone Manufacturer

ro.product.brand=samsung

This name is the codename of the

device.

For example-

HTC Explorer - pico,

Nexus 7 - grouper

Nexus 4 - mako

Galaxy Ace - cooper

Grand - baffin

ro.product.name=baffin

System Images

It is the first instruction set (CPU + ABI

convention type) of the code. Ours is an arm type arch cpu and abi version 7a )

ro.product.cpu.abi=armeabi-v7a

ro.product.cpu.abi2=armeabi

Default Country settings.

Language of software

Region of software

ro.product.locale.language=en

ro.product.locale.region=GB

If you not able to connect to your wifi, you can try to set here the same number of channels as your router currently got. For example: Your router is set to 12 channels you can paste the same number in here.

ro.wifi.channels=

Here you can set the standard media sounds for each notification. But the file should be present in system/media/...

ro.config.ringtone=S_Over_the_horizon.ogg

ro.config.notification_sound=S_Whistle.ogg

ro.config.alarm_alert=A_toy_watch.ogg

Your phone is still usable, even if sim card is not inserted.

keyguard.no_require_sim=true

Default format of date

ro.com.android.dateformat=mm-dd-yyyy

Your bluetooth name

net.bt.name=Samsung Galaxy Grand Duos

Disable Boot Animation

debug.sf.nobootanimation=1

Your battery capacity (in MHz)

ro.semc.batt.capacity=1200

The setup wizard when you flash a custom rom and it asks your language, gmail id etc

ro.setupwizard.mode=DISABLED (or ENABLED or OPTIONAL)

Here you can set the default density (in pixel per inch)(default is 240)

ro.sf.lcd_density=240

Minimum brightness of your screen

ro.lcd_min_brightness=40

Your default brightness

ro.lcd_brightness=160

Basically you control the class-loading and dalvik-vm there. Here you can set different values.

v=a means verify all,

v=f means verify full,

o=v means optimize verify,

v=n will turn off bytecode verification

u=n means do not optimize for unprocessor

m=y means register maps yes

dalvik.vm.dexopt-flags=m=y

Enables multi touch

ro.product.multi_touch_enabled=true

Max number of multi touches

ro.product.max_num_touch=2

Disable sending usage data

ro.config.nocheckin=1

Here you can set the delay of time your phone starts to ring when you recieve a call.

ro.telephony.call_ring.delay=0 (0 means disabled)

Disable waking up of phone by volume buttons ro.config.hwfeature_wakeupkey=0

Off the proximity quickly after call

mot.proximity.delay=25

ro.lge.proximity.delay=25

This property is supposed to keep the launcher in memory under the assumption that it would somehow make it faster

ro.HOME_APP_ADJ=1

Allows your phone to use an ext-4 file system

ro.ext4fs=1

Disables debug icon on status bar

persist.adb.notify=0

Key lights stay on while screen is on

ro.mot.buttonlight.timeout=0

Disable notification sound when SD is inserted

persist.service.mount.playsnd=0

Disables location of device. Also delete /system/app/networklocation.apk and /system/framework/com.android.location.provider

.jar

ro.com.google.locationfeatures=0

ro.com.google.networklocation=0

To enable the timeout of hard key lights to stay on when screen is on and lights off when screen is off

ro.mot.buttonlight.timeout=0

To enable the menu button too unlock the phone

Not sure if it works

ro.config.hw_menu_unlockscreen=true

Proximity sensor debounce time

mot.proximity.delay=450

mot.proximity.distance=60

Default data roaming is enabled

ro.com.android.dataroaming=true

Judging from its name I assume people think it disables some kind of logging mechanism. But 'no'.The “ulog” referred to in this property is an HTC-specific service that HTC calls the User Behavior Logging Service. This service is centered around tracking user behavior related to the HTC Sense launcher. The HTC ULog tracks some basic things like the number of ANRs and/or crashes, but it also potentially tacks things like your wallpaper selection, your installed apps and your locatio (HTC specific)

profiler.force_disable_ulog=1

Unlike the latter, this one actually does turn off sending device crash log data to HTC. This will make your device run faster/smoother/better (HTC specific)

profiler.force_disable_err_rpt=1

# Increase Quality Of MediaStreaming

media.stagefright.enable-meta=true

media.stagefright.enable-scan=true

media.stagefright.enable-http=true

media.stagefright.enable-record=false

# Net Speed Tweaks

net.tcp.buffersize.default=4096,87380,256960,4096,

16384,256960

net.tcp.buffersize.wifi=4096,87380,256960,4096,163

84,256960

net.tcp.buffersize.umts=4096,87380,256960,4096,163

84,256960

net.tcp.buffersize.gprs=4096,87380,256960,4096,163

84,256960

net.tcp.buffersize.edge=4096,87380,256960,4096,163

84,256960

# Google DNS Tweak

net.wlan0.dns1=8.8.8.8

net.wlan0.dns2=8.8.4.4

net.pdp0.dns1=8.8.8.8

net.pdp0.dns2=8.8.4.4

net.ppp0.dns1=8.8.8.8

net.ppp0.dns2=8.8.4.4

net.eth0.dns1=8.8.8.8

net.eth0.dns2=8.8.4.4

net.gprs.dns1=8.8.8.8

net.gprs.dns2=8.8.4.4

# Touch Responsiveness

Scrolling Responsiveness

Faster Scrolling

debug.performance.tuning=1

video.accelerate.hw=1

windowsmgr.max_events_per_sec=500

ro.max.fling_velocity=12000

ro.min.fling_velocity=8000

# Media Tweaks

Increase photo and video quality

ro.media.dec.jpeg.memcap=8000000

ro.media.enc.hprof.vid.bps=8000000

ro.media.enc.jpeg.quality=100

Makes streaming videos stream faster

media.stagefright.enable-player=true

media.stagefright.enable-meta=true

media.stagefright.enable-scan=true

media.stagefright.enable-http=true

Better Flashlight intensity & camera-flash quality

ro.media.capture.flash=led

ro.media.capture.flashMinV=3300000

ro.media.capture.torchIntensity=65

ro.media.capture.flashIntensity=70

# Signal Tweaks

Defines weither to use [0=UMTS] [1=HSDPA only] [2=HSDPA & HSUPA] [5=No significant information has been found but it makes the switch between WiFi and HSxPA nearly instantaneous (note works like "2" but better)]

Here you can improve your Data speed if your provider supports it. Set this to 0 if you want lower speeds, and up to 2 for faster speeds.

ro.ril.hsxpa=2

Defines what class speeds to use with EDGE.

Class 10 will significantly save battery, unless you use EDGE/GPRS instead of 3G)

12 is the default value for most modern phones.

Setting this value to 12 can improve the data speed significant on lower connections.

ro.ril.gprsclass=10

0=off

1=Default

no change when turned off. In some phones stability is increased when turned off.

ro.ril.hep=1

Enable "dual transfer mode" on EDGE networks. Requires different GPRS class settings. Only set this to 1 if your network allows simultaneous transfer of Circuit switched (CS) voice and Packet switched (PS) data over the same radio channel (ARFCN). Turning this off on some carriers, including Optus (AU) and AT&T increases upload speeds.

ro.ril.enable.dtm=1

Enable increased ciphering on

HSDPA/HSUPA, for increased security, but decrease in performance.

ro.ril.enable.a53=1

Adds the 3G prefix e.g. Optus 3G, etc. Purely cosmetic

ro.ril.enable.3g.prefix=1

Other signal tweaks

ro.ril.hsdpa.category=10

ro.ril.htcmaskw1.bitmask=4294967295

ro.ril.htcmaskw1=14449

ro.ril.hsupa.category=5

# Dalvik VM tweaks

This controls the smallest amount of memory given to a single application.

dalvik.vm.heapstartsize=5m

This value represents the maximum allowed amount of memory that the Dalvik Virtual Machine can allocate to the applications. A higher value means faster apps but more RAM consumption.

dalvik.vm.heapgrowthlimit=48m

The dalvik.vm.heapsize property defines an absolute maximum for the heap size for an application

dalvik.vm.heapsize=128m

This point stands for "Debug SurfaceFlinger Hardware" or GPU hardware acceleration

debug.sf.hw=1

Explained Earlier(change to this to load apps faster and free more ram)

dalvik.vm.dexopt-flags=m=v,o=y or m=y

This property can set the execution mode of the Dalvik VM. The VM can run in three modes: fast, portable, and JIT. It is possible to compile Android without JIT support, but the default is to include it. In general, JIT is the execution mode you are going to want on your device. This is why you will see most build.prop files setting this property to “int:jit”.

In ICS or lower , there is no need to define this setting in your build.prop

dalvik.vm.execution-mode=int:jit or int:fast

Others

dalvik.vm.heaptargetutilization=0.75

dalvik.vm.heapmaxfree=2m

dalvik.vm.lockprof.threshold=500

# Improve battery

improve battery under no signal

ro.mot.eri.losalert.delay=1000

Bluetooth OPP low speed to save power

debug.bt.lowspeed=true

Wifi to scan less frequently

wifi.supplicant_scan_interval=240

System can free more Ram when needed

persist.sys.purgeable_assets=1

This property purports to significantly increase your battery life by putting signaling your device to use a better power mode when your phone is idle. Recommended values range from 0, 1, 4 with the most common be 1

pm.sleep_mode=1

To save battery turn off wifi, internet, bluetooth, gps, lower the brightness at night, kill all apps running in background, clear ram, underclock if kernal supports and also switch off the animations settings>display>no animation.