I originally installed the first 2.1 that came out. It unrooted my phone. I had to download the Dev Kit and use a terminal to setup SU.
Here is the last of the process:
24) at the command prompt, type "adb shell" - it should drop you to the following prompt:
$
25) type "su" and it should drop you to the following prompt:
#
26) type the following, in order (don't include the #):
# mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
# cd /system/bin
# mv su osu
# cat /data/local/su > su
# chmod 6755 su
27) type "ls -l *su" to verify that you have two files: the original "su" that came with the phone is now named "osu", and the new one you just put in place. You should see something like this:
-rwsr-sr-x root root 76200 2008-08-01 05:00 osu
-rwsr-sr-x root root 76200 2009-05-30 11:28 su
28) finish by running a sync, and then executing "reboot" to reboot the phone:
# sync
# reboot
29) once the phone is back up, go to the Market and download a terminal emulator if you don't have one already (search for "terminal" in the Market, there's "Android Terminal Emulator, Better Terminal Emulator Pro, Terminal Emulator in that list - you can choose which one you want. I am using Better Terminal Emulator Pro)
30) launch your terminal program. at the prompt, type "su" and hit enter. you should get the following:
$ su
su: access granted, courtesy of
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