Updated for 2.2.2 in March 2011. Everything is the same, check the site for the revised and simplified instructions, or keep reading for the older and different instructions. Which one is less confusing is for you to decide. I suck at guide writing, but this is the easiest way to keep root for sure.
Updated for 2.2.1 on Dec 15. I am leaving the old instructions here in case they are helpful, but the ones on my web site should be easier to understand. There is a new hack for the FRG83D update there too.
Old instructions are below.
FRG22D update: This guide was written for FRG01B. I made a patch for FRG22D and it is on my site. The steps are the same as before, but with the new files - "copy /b signed-voles-FRG22D-from-FRG01B.688e3520.zip+FRG22D-root.zip update.zip"
All files needed are available on my web site: Android - whiterabbit.org unless you still need to root your phone or downgrade to 2.0.1, the files needed for that will be linked to from those guides. The purpose of installing this way is to use the original OTA updates from Google, and only modify them enough to have root access. When you are done, you will have a system that is capable of installing the next OTA (gingerbread) when it arrives. Hopefully we will be able to patch it in the same way to keep root. This is only for people who don't want to run custom roms, but still want to have root.
If you aren't rooted yet, you need to do that first: http://androidforums.com/all-things-root-droid/136508-guide-all-things-root-related.html
If you are on stock rooted 2.1 with a custom recovery partition or the 2.1 recovery partition (you need the stock 2.0.1 recovery for this):
First make sure you have a stock recovery partition. If you are using a custom recovery partition like sprecovery, get recovery.img, put it on your sdcard, get to a prompt (connectbot, local connection - or adb shell) and run su. run "flash_image recovery /sdcard/recovery.img". Now you have the stock 2.0.1 recovery partition. Go to the next step.
If you are on stock rooted 2.1 with the stock 2.0.1 recovery partition:
Download signed-voles-FRG01B-from-ESE81.e48e48ff.zip and FRG01B-root.zip, then at a dos prompt where both files are, run "copy /b signed-voles-FRG01B-from-ESE81.e48e48ff.zip+FRG01B-root.zip update.zip" and then copy that update.zip to your sd card. Boot holding down X and hold down volume up and tap the camera button. Select apply sdcard:update.zip with the dpad and press enter. Now wait a long time for it to apply the update, and you will have rooted stock froyo. You are done and can stop reading this thread.
If you are on unrooted 2.2, you should probably read this thread instead: http://androidforums.com/all-things-root-droid/141116-guide-rooting-2-2-a.html
Your other option is to downgrade to stock 2.0.1 using this guide: Unroot/Unbrick using .sbf post from -ikithme- - Droid Forum - Verizon Droid & the Motorola Droid Forum
You will lose everything, so back anything important up. Hit the menu button from the home screen, pick settings, privacy settings, and pick "back up my data". That will go a long way towards backing things up. Then follow that guide.
Now you have unrooted 2.0.1, so upgrade to rooted 2.1. Download signed-voles-ESE81-from-ESD56.fa406da6.zip and ESE81-root.zip, then at a dos prompt where both files are, run "copy /b signed-voles-ESE81-from-ESD56.fa406da6.zip+ESE81-root.zip update.zip" and then copy that update.zip to your sd card. Boot holding down X and hold down volume up and tap the camera button. Select apply sdcard:update.zip with the dpad and press enter. Now wait a long time for it to apply the update, and you will have rooted stock 2.1 along with the stock 2.0.1 recovery partition, which means you can go back to the beginning of this guide.
Updated for 2.2.1 on Dec 15. I am leaving the old instructions here in case they are helpful, but the ones on my web site should be easier to understand. There is a new hack for the FRG83D update there too.
Old instructions are below.
FRG22D update: This guide was written for FRG01B. I made a patch for FRG22D and it is on my site. The steps are the same as before, but with the new files - "copy /b signed-voles-FRG22D-from-FRG01B.688e3520.zip+FRG22D-root.zip update.zip"
All files needed are available on my web site: Android - whiterabbit.org unless you still need to root your phone or downgrade to 2.0.1, the files needed for that will be linked to from those guides. The purpose of installing this way is to use the original OTA updates from Google, and only modify them enough to have root access. When you are done, you will have a system that is capable of installing the next OTA (gingerbread) when it arrives. Hopefully we will be able to patch it in the same way to keep root. This is only for people who don't want to run custom roms, but still want to have root.
If you aren't rooted yet, you need to do that first: http://androidforums.com/all-things-root-droid/136508-guide-all-things-root-related.html
If you are on stock rooted 2.1 with a custom recovery partition or the 2.1 recovery partition (you need the stock 2.0.1 recovery for this):
First make sure you have a stock recovery partition. If you are using a custom recovery partition like sprecovery, get recovery.img, put it on your sdcard, get to a prompt (connectbot, local connection - or adb shell) and run su. run "flash_image recovery /sdcard/recovery.img". Now you have the stock 2.0.1 recovery partition. Go to the next step.
If you are on stock rooted 2.1 with the stock 2.0.1 recovery partition:
Download signed-voles-FRG01B-from-ESE81.e48e48ff.zip and FRG01B-root.zip, then at a dos prompt where both files are, run "copy /b signed-voles-FRG01B-from-ESE81.e48e48ff.zip+FRG01B-root.zip update.zip" and then copy that update.zip to your sd card. Boot holding down X and hold down volume up and tap the camera button. Select apply sdcard:update.zip with the dpad and press enter. Now wait a long time for it to apply the update, and you will have rooted stock froyo. You are done and can stop reading this thread.
If you are on unrooted 2.2, you should probably read this thread instead: http://androidforums.com/all-things-root-droid/141116-guide-rooting-2-2-a.html
Your other option is to downgrade to stock 2.0.1 using this guide: Unroot/Unbrick using .sbf post from -ikithme- - Droid Forum - Verizon Droid & the Motorola Droid Forum
You will lose everything, so back anything important up. Hit the menu button from the home screen, pick settings, privacy settings, and pick "back up my data". That will go a long way towards backing things up. Then follow that guide.
Now you have unrooted 2.0.1, so upgrade to rooted 2.1. Download signed-voles-ESE81-from-ESD56.fa406da6.zip and ESE81-root.zip, then at a dos prompt where both files are, run "copy /b signed-voles-ESE81-from-ESD56.fa406da6.zip+ESE81-root.zip update.zip" and then copy that update.zip to your sd card. Boot holding down X and hold down volume up and tap the camera button. Select apply sdcard:update.zip with the dpad and press enter. Now wait a long time for it to apply the update, and you will have rooted stock 2.1 along with the stock 2.0.1 recovery partition, which means you can go back to the beginning of this guide.