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Recovery mode and memory tweaks


  1. Nilpotent

    Nilpotent Well-Known Member

    Before discussing memory tweaks, I will discuss a little how to enter the recovery mode as I've seen several posts on xda suggesting weird ways to enter the recovery mode. I wanted to post pictures but my camera does not focus well on the screen and the pictures are blurred for some reason.

    Usual disclaimer: you are responsible of what you do with your system and if you follow any of what is written here, it is your choice. The more you go at low level, the more risk to break your phone...

    What is the recovery mode for ?
    Basically, you have no more warranty, you have played too much with your phone and it is soft bricked (boot loop, etc). The recovery mode offers the possibility to do a factory reset which may help you (I did not do it but I think you loose most of the phone apps and your data). If your phone works and you enter this mode, be careful as you can erase everything...

    How to enter (stock) recovery mode.
    1) Press an hold volume up
    2) Press and hold power (do not release volume up)
    3) When you see the samsung logo release the power button (if you don't release power, the phone may reboot several time and may end up to boot as usual).
    3 bis) It may be ok to release volume up after you see the samsung logo but I usually keep it pressed until I see the android with the white open box.
    4) After T-mobile exhibit II logo, you will see an android with a white open box. This is recovery
    4bis) if you do nothing else, your phone will reboot.
    5) Press the menu button (left button at the bottom of the screen), the screen will get darker. If it does not go darker, you probably missed the button and have to press again. If you pressed twice, the screen will go dark then back to normal and the phone will probably reboot normally.
    6) After the screen goes dark, do nothing for a few seconds, the recovery menu will appear with the following options
    - reboot system now
    - apply update from sdcard
    - wipe data/factory reset
    - install fota

    The reboot option is selected by default. To go down on the menu use volume down. To go up use volume up. To action the selected option, press home button (second button from the left at the bottom of the screen). If you press the menu button, the menu will disappear but the phone does not seem to reboot normally. If you can press menu again the see the recovery menu.

    That's it !

    Note: phone on battery vs phone plugged. It seems easier to boot in any mode when the phone is on battery. When it is plugged, pushing power does not work all the time, you may have to try several time. The problem to be on battery is if you are low on battery, you make a factory reset and you get out of battery in the middle of the process, I think you may be in really really big trouble.


    Memory tweaks:

    v6 supercharger (http://forum.xda-developers.com/showthread.php?t=991276)

    I simply downloaded the version RC4 here [​IMG] V6_SuperCharger_for_Android-update9_RC4.sh.pdf (http://forum.xda-developers.com/showpost.php?p=18703418&postcount=5021)

    and followed the tutorial here

    http://forum.xda-developers.com/showthread.php?t=1126940

    I recommend to read and follow the tutorial and read what the script says !

    Just in case, I give a few more details that may be different from the tutorial and could be helpful:
    I renamed V6_SuperCharger_for_Android_update9_RC4.sh.pdf into V6_SuperCharger_for_Android_update9_RC4.sh (that does not matter apparently) and put it into /mnt/sdcard (or /sdcard, it's the same place)

    I downloaded busybox v1.18.2 (in /system/bin) through busybox installer

    When the script told me if I wanted to create local.prop (or else I would have a small chance of boot loop), I said yes.

    I've been choosing option 6 (since then, I've used 7 and nitro lag nullifier by launching the script again)

    Then I browse with script manager to /data/99Supercharger.sh and set it to launch as root and on boot.

    I launched again supercharger but not sure it's useful.


    Disabling verify-bytecode
    Thanks for GVC to have mentioned this memory tweak some time ago (http://androidforums.com/samsung-exhibit-2-4g/475101-phone-memory-storage.html)

    The full description is here. What I have written is basically a copy/paste adapted to the specifics of our phone
    http://forum.xda-developers.com/showthread.php?t=1263119

    I've done it (few months ago, this comes from the notes I took at that time) but stock ROM is odexed so it's not really useful for me but I can confirm that I had no problem with any apps since I've done this. So either I totally messed up or most of the apps are working fine... This is supposed to give a speed boost for deodexed ROMs (a lot of custom ROMs are deodexed).

    I advise caution when you modify build.prop I have no idea what happens if you make a mistake with the file but I would say it's very very bad.

    1) Open Terminal Emulator on phone or adb shell from PC and type the following.
    adb shell (this is not needed from the terminal)
    su
    setprop dalvik.vm.verify-bytecode false
    setprop dalvik.vm.dexopt-flags v=n,o=v
    rm /data/dalvik-cache/*

    2) Add these to /system/build.prop
    dalvik.vm.verify-bytecode = false
    dalvik.vm.dexopt-flags=v=n,o=v

    (Copy local.prop or build.prop to SD and edit them. Copy back afterwards. If lines starting with dalvik.vm.verify-bytecode or dalvik.vm.dexopt-flags exist already, please modify them as above. )

    For me, the end of the build.prop looks like this
    #dalvik.vm.dexopt-flags=m=y
    net.bt.name=Android
    dalvik.vm.stack-trace-file=/data/anr/traces.txt
    dalvik.vm.verify-bytecode = false
    dalvik.vm.dexopt-flags=v=n,o=v

    Also type following in adb shell or terminal emulator.

    adb shell (this is not needed from the terminal)
    su
    rm /data/dalvik-cache/*
    reboot



    Reversing the change/undo tweak (I DID NOT TRY, I assume you have to revert the build.prop file first).
    adb shell (this is not needed from the terminal)
    su
    setprop dalvik.vm.verify-bytecode true
    rm /data/dalvik-cache/*
    reboot

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    surgerush and OmgitzFire like this.
  2. OmgitzFire

    OmgitzFire Member

    Will booting into this recovery allow me to install cwm if I have the .zip ? is apply update from sdcard the correct way to do it ?
  3. sirphilk

    sirphilk Active Member

    Worked that way for me. The zip must be in internal sd though.
    OmgitzFire likes this.
  4. OmgitzFire

    OmgitzFire Member

    Ok great thanks.
    But what do you mean internal sd? Can I just put the zip anywhere on the sd card or does it have to be in a specific folder ?
  5. teerout

    teerout Member

    i think i just put the cwm file on the "phone drive" not in any folder. so when your pc reads your phone when you connect it, the main phone directory. (anyway i went through terminal emulator to install cwm)
  6. Nilpotent

    Nilpotent Well-Known Member

    I think he meant either /mnt/sdcard or /sdcard (same thing), but not /sdcard/external_sd
  7. OmgitzFire

    OmgitzFire Member

    Alright thanks guys , I couldn't get into recovery mode using this but I was able to by using rom toolbox
    thanks again
  8. Nilpotent

    Nilpotent Well-Known Member

    Interesting. I can go in recovery each time... Can you describe what is the phone doing? Does it boot in normal mode?
  9. OmgitzFire

    OmgitzFire Member

    I tried to follow the directions but it seems to boot up normally every time I tried .. I prolly wasn't doing something right .
  10. sirphilk

    sirphilk Active Member

    Sorry, yes that is what I meant. Also when you connect to PC you will get two drives. One is the internal memory and the other is the External SD Card.
  11. Nilpotent

    Nilpotent Well-Known Member

    Added a link and a short description on how to use v6 supercharger.
  12. OmgitzFire

    OmgitzFire Member

    Thanks for the supercharger link
    I haven't used it on my exhibit (I don't think it needs it yet) but I did on my bro s samsung intercept and there's lots of improvement there .
  13. CMViking1

    CMViking1 New Member

    I have looked everywhere on my exhibit 2 4g and cannot find /mnt/sdcard.

    I have gotten as far as rooting my phone, but then I am stuck. This is my first time doing any phone hacks so any help would be greatly appreciated.
  14. surgerush

    surgerush Well-Known Member

    Does ROM manager support our phone yet to flash CWM? I still haven't done it yet. If not, where is the .zip to do so in recovery?

    Edit: Never mind, I got it, found it here in case anybody else hasn't.

    Edit: Ok, I went into recovery, applied update from sd card, but rom manager still isn't recognizing that it has been installed. I've never done anything with CWM before, what am I missing or doing wrong?

    Edit: Ok, when I got into Script Manager and hit the cwm5504.zip, it takes me to rom manager and asks if I want to reboot into CWM recovery and continue the installation... Is this what I doi? I thought I already did that by going into recovery and applying the update from the sd card.

    Edit: Lol, nevermind again, went back into recovery and everything wortked fine, currently making a backup onto my external sd. So I just can't do any of this through rom manager then? Which makes rom manager pretty much useless as of now?
  15. Nilpotent

    Nilpotent Well-Known Member

    Yes, I think some work is needed to get something interesting through ROM manager. Seems to me the main interest is to boot into recovery and there are other ways to do that !
  16. surgerush

    surgerush Well-Known Member

    I just installed the most recent version of V6, I just wanted to let you guys know that thew newest version recommended that I use one of the 512 settings for this phone. So if you're using one of the older versions of V6, using one of the 512 settings may work better with the phone.

    I ended up going with the lowest 512 setting it had, just to be safe.

    Edit: I just realized I had update 5 installed, not 6... I just tried 6 and it would not work. So I'm back on 5.
  17. Nilpotent

    Nilpotent Well-Known Member

    I made the guinea pig for the disabling verify-bytecode tweak. I added how I did it on the first post.

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