Simple (not one-click) root for stock ROM & kernel

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Update: One click root has been using this "simple" method since version 2.2.7. If you're rooting your phone for the first time, please try that first. Consider this thread to be purely informational for those who want step-by-step details of how the process works.

I've been suspicious of the joeykrim root method since it was first posted at SDX. I finally got my Epic yesterday and confirmed that is, indeed unnecessary. I don't fault joeykrim though, he ported the working root method from the Moment to the Epic without actually having access to an Epic himself.

Anyways, the joeykrim root method is unnecessarilly complex becuase it works around an RFS permissions bug which loses the setuid bit on the Moment. It appears the Galaxy S phones have this bug fixed, which is why the root methods on the I9000, Vibrant, Captivate, Fascinate, etc., are much simpler.

So, for the simple root:

• First, make sure joeykrim root is not installed.
• Upgrade to DI18 (not strictly necessary, but you'll want to do it).
• Setup a working adb from the Android SDK and whatever drivers are necessary for your platform.
• Download rageagainstthecage-arm5.bin from the C skills blog (link removed due to my newbieness) or from any of the one-click root packages.
• Download su-2.3.6.1-ef-signed.zip and extract "system/bin/su" and "system/app/Superuser.apk" to a temporary directory you'll be working from.
• Enable USB debugging on your phone and connect it to your computer.

Now, open a command prompt/shell on your computer and cd to the appropriate temporary directory. Run:

adb push rageagainstthecage-arm5.bin /data/local/tmp
adb shell chmod 755 /data/local/tmp/rageagainstthecage-arm5.bin
adb shell /data/local/tmp/rageagainstthecage-arm5.bin

and confirm you have a working root shell. Then continue with:

adb push su /system/xbin
adb shell chmod 4755 /system/xbin/su
adb install Superuser.apk

That's it! You should have a working root via su & the Superuser package. At least, I did.

Note that the preceeding steps installs Superuser.apk to /data, which is what I prefer to do. This means if you do a "Factory data reset" su will be temporarilly broken until you reinstall the Superuser.apk package. Since installing the package itself doesn't require root, this is easily done after a /data reset.

Also note that I did not perform a /system remount-rw anywhere. At least on my Epic, /system appears to always be mounted read-write so it's an unnecessary step. It's actually the "joeykrim-root.sh" script that remounts /system read-only during the boot process, which is why folks who don't use root kernels have run into this problem before. I'm not sure why joeykrim's script does that, I guess he probably assumed /system is mounted read-only by default. There's arguments that /system should be read-only, but I didn't touch it in case some Samsung stuff depends on it being read-write.

Finally, if you're already rooted via joeykrim or are running a root kernel, there's nothing really to be gained by doing this. I'm just throwing this out there as I perfer to make the minimum invasive changes possible to obtain root.

Wow, that was really informative. To check for Super user you:

Type: adb shell

then type: SU

You should get a # sign if you have root. Correct?

In the original Noobln post method would the Epic keep root even after a wipe therefore not needing to re-apply the superuser apk again? That might be a reason why folks would want to go the more invasive route (considering rooters seems to change ROMS fairly often which requires wipes sometimes). Either way, keeping a copy of the apk file on your SD card is no big deal.

Originally Posted by mkasick

Also note that I did not perform a /system remount-rw anywhere. At least on my Epic, /system appears to always be mounted read-write so it's an unnecessary step. It's actually the "joeykrim-root.sh" script that remounts /system read-only during the boot process, which is why folks who don't use root kernels have run into this problem before. I'm not sure why joeykrim's script does that, I guess he probably assumed /system is mounted read-only by default. There's arguments that /system should be read-only, but I didn't touch it in case some Samsung stuff depends on it being read-write.

This explains a lot of problems! thanks

EDIT- another noob question- why do you prefer to have superuser installed to /system/data- why not put it in /system/app? Also if I want to install busybox where is the best location to put it?

Originally Posted by ZenInsight

Wow, that was really informative. To check for Super user you:

Type: adb shell

then type: SU

You should get a # sign if you have root. Correct?

Once you run rageagainstthecage-arm5.bin, you should get a root-shell automatically every time you run "adb shell" after until you reboot the phone. Yes, you can tell it's a root shell since it uses the "#" prompt. This is the important part to check, since if the exploit doesn't work, you'll have to run it again. But I haven't seen it not work.

After su is installed and you reboot, your steps are correct: run "adb shell", run "su", then you'll be prompted on the phone scren to authorize access and once you allow it you'll end up with a "#" prompt.

Originally Posted by ZenInsight

In the original Noobln post method would the Epic keep root even after a wipe therefore not needing to re-apply the superuser apk again?

noobnl installs Superuser.apk to /system, you can do that here too. Just replace the "adb install Superuser.apk" step with "adb push Superuser.apk /system/app". It's independent of the joeykrim scripts.

With my captivate we have many update.zip root methods to choose from. Any chance this will be coming to the epic? Have a friend with an epic and command lines would be too much and one click didn't work.

Sent from my SAMSUNG-SGH-I897 using XDA App

Originally Posted by jimmyz

why do you prefer to have superuser installed to /system/data- why not put it in /system/app?

I prefer to keep consistent with the idea that user-installed applications go in /data, and stock-installed-and-unmodified applications remain in /system/app. This way, upgrading Superuser.apk doesn't require a root-shell/root-explorer, you can remove it or upgrade it the way you do with any user installed application--adb install, side-loading via an sdcard, or downloading it from the market.

Plus, in general I prefer to keep my /system as untouched as possible. For example, I don't remove stock apps either. The "su" binary has to be installed in /system to persist after a /data wipe, and busybox is best installed to /system so it's in PATH (haven't looked into modifying the default PATH yet). Otherwise I try to keep /system alone.

Originally Posted by jimmyz

Also if I want to install busybox where is the best location to put it?

Android's default PATH provides four places for busybox to be installed: /sbin, /system/bin, /system/sbin, and /system/xbin. /sbin is part of the initramfs, in other words it's controlled by the kernel you're running. You can install busybox to any of the three /system/*bin directories, but I prefer /system/xbin.

In the traditional Unix conventions, "/usr/bin" is for user-runnable stock-installed programs, and "/usr/sbin" is for root-requiring (superuser-runnable) stock-installed programs. "xbin" isn't part of the standard convention, but I'd guess it's intended for "extra binaries" that are not part of the stock installation (much like /usr/local/bin), thus it seems like an appropriate location for a user-added "su" and "busybox" programs.

The second reason is that "xbin" is relatively empty, so if you want to create the applet symlinks (i.e., so that you can call "cp" instead of "buybox cp") it won't overwrite the stock toolbox symlinks. Also, since "xbin" is last on the default PATH, any programs provided by both toolbox and busybox will default to the toolbox version--which would be important for stock system scripts that might run into compatibility issues if they were to use the busybox versions instead.

To install busybox, grab a copy of the binary from somewhere (one click packages, a copy of stericson.busybox.apk, etc.). Then, once rooted run:

adb push busybox /data/local/tmp
adb shell
su # Authorize on phone screen
cat /data/local/tmp/busybox > /system/xbin/busybox
chown root.shell /system/xbin/busybox
chmod 755 /system/xbin/busybox
rm /data/local/tmp/busybox
/system/xbin/busybox --install -s /system/xbin

Originally Posted by jhnstn00

With my captivate we have many update.zip root methods to choose from. Any chance this will be coming to the epic?

I don't believe so. The I9000/Vibrant/Captivate have recoveries that don't check the signature of update.zip (as I understand, or maybe they do but only require test keys) which makes rooting-via-recovery possible. Unfortuntaely the Epic and Fascinate do perform signature checks, so we can't enable root via stock-recovery.

That said, the Fascinate one-click methods should also work on the Epic. Although depending on why your friend couldn't get the Epic one-click to work, the Fascinate one may not work either.

Originally Posted by mkasick

I prefer to keep consistent with the idea that user-installed applications go in /data, and stock-installed-and-unmodified applications remain in /system/app. This way, upgrading Superuser.apk doesn't require a root-shell/root-explorer, you can remove it or upgrade it the way you do with any user installed application--adb install, side-loading via an sdcard, or downloading it from the market.

Plus, in general I prefer to keep my /system as untouched as possible. For example, I don't remove stock apps either. The "su" binary has to be installed in /system to persist after a /data wipe, and busybox is best installed to /system so it's in PATH (haven't looked into modifying the default PATH yet). Otherwise I try to keep /system alone.


Android's default PATH provides four places for busybox to be installed: /sbin, /system/bin, /system/sbin, and /system/xbin. /sbin is part of the initramfs, in other words it's controlled by the kernel you're running. You can install busybox to any of the three /system/*bin directories, but I prefer /system/xbin.

In the traditional Unix conventions, "/usr/bin" is for user-runnable stock-installed programs, and "/usr/sbin" is for root-requiring (superuser-runnable) stock-installed programs. "xbin" isn't part of the standard convention, but I'd guess it's intended for "extra binaries" that are not part of the stock installation (much like /usr/local/bin), thus it seems like an appropriate location for a user-added "su" and "busybox" programs.

The second reason is that "xbin" is relatively empty, so if you want to create the applet symlinks (i.e., so that you can call "cp" instead of "buybox cp") it won't overwrite the stock toolbox symlinks. Also, since "xbin" is last on the default PATH, any programs provided by both toolbox and busybox will default to the toolbox version--which would be important for stock system scripts that might run into compatibility issues if they were to use the busybox versions instead.

To install busybox, grab a copy of the binary from somewhere (one click packages, a copy of stericson.busybox.apk, etc.). Then, once rooted run:

adb push busybox /data/local/tmp
adb shell
su # Authorize on phone screen
cat /data/local/tmp/busybox > /system/xbin/busybox
chown root.shell /system/xbin/busybox
chmod 755 /system/xbin/busybox
rm /data/local/tmp/busybox
/system/xbin/busybox --install -s /system/xbin

You sir are a true gentleman! Thank you for the informative answers- its great to have you over here! I have one more question- why can't I usually push directly to /system ?

Originally Posted by jimmyz

why can't I usually push directly to /system ?

Pushing directly to /system requires running the adb service on the phone as the root user, so that it has permissions to write to that directory. Usually adb runs on the phone unprivileged, so you can only push to world-writable directories.

Running rageagainstthecage-arm5.bin actually changes this. The exploit forces the adb service to run as the root user, which is why "adb shell" gives you a root shell and "adb push" to /system does work, until the phone is restarted.

Interesting enough, the adb service also runs as root by default in the Android emulator. So there's probably a configuration setting, somewhere, to make it do that. In general it's safer to run adb unprivileged though, and "su" to move files to /system once uploaded elsewhere on the phoe.

Originally Posted by mkasick

Pushing directly to /system requires running the adb service on the phone as the root user, so that it has permissions to write to that directory. Usually adb runs on the phone unprivileged, so you can only push to world-writable directories.

Running rageagainstthecage-arm5.bin actually changes this. The exploit forces the adb service to run as the root user, which is why "adb shell" gives you a root shell and "adb push" to /system does work, until the phone is restarted.

Interesting enough, the adb service also runs as root by default in the Android emulator. So there's probably a configuration setting, somewhere, to make it do that. In general it's safer to run adb unprivileged though, and "su" to move files to /system once uploaded elsewhere on the phoe.

I am learning a lot!!! Could you take a look at koush's kernel here, with it I noticed that when using adb I got the # prompt right away and was able to push to /system- maybe he was able to figure out the config settings? Once again thanks!!!
one more ? (feel free to ignore this one) what actually happens when you do

adb shell /data/local/tmp/rageagainstthecage-arm5.bin

and how does that give you permanent root?