Clearing Dalvik Cache without root? I recently tried updating my Motorola Atrix 4g. It downloaded, and then it booted down to try to update. However, instead of updating, it ends up booting to a screen that just says 

Failed to boot 2
Starting RSD mode


If I take out the battery, I boot up the phone for about 60 seconds before it starts shutting down again.

The phone is rooted, and it seems like it starts shutting down as soon as Android starts giving out root privileges.

Looking through different forums online, it seems as though the best solution to stop the phone from trying to update (without erasing all my data by resetting the phone to factory settings) is to clear the Dalvik cache.

The problem I am having is that so far, it seems that in order to clear the cache, I need root, but as soon as my phone has been on long enough to give out root, it restarts, and I can't do anything with it. To make the problem worse, I seem to be unable to boot into recovery...

Is there any way to clear the Dalvik Cache (really, really fast, and) without root (or recovery)?
I finally figured it out, here's how I did it:  

Even though adb can't get root, and the phone it's self can't get root, as it turns out, there is in fact one more way to clear the cache without fully booting the phone.


Turn the phone off
Make sure you have fastboot working on your computer
Press the power button on the phone and then hold down the volume down button until you see fastboot, then hit the volume up button.
Open a terminal window, and type the following

sudo su
fastboot erase cache



And (apparently) voilà!  The cache is cleared!!