A friend over at Google provided me with an unlocked Android phone, which I’ve been poking around with here and there doing some development. I hadn’t really poked around with the phone itself all that much, meaning looking at hacks and usage tricks and whatnot. Yesterday I decided I wanted to update to the latest firmware (RC33) however, so the journey began. I have my G1 running on the AT&T network, which is where some of the complexity comes from.

I started out with the normal instructions for manually installing the RC33 update, which are pretty actually slick and simple. However, I was getting a failed check when trying to install the firmware. I assume there’s some internal ID that identifies the phone as a TMobile phone or not, and my dev phone doesn’t have that, so the installer was throwing some assertion failure check. So I figured I would try out one of the jailbroken images if I’m going to have to muck around for a while anyway.

There is an alternative version of the RC33 update available, called the JF33 sometimes, and other times the JF RC33. The JF stands for Jesusfreak, the forum user who repacks the roms and has apparently provided test keys that can be used to downgrade a unit. Once you know what you’re looking for, there are tons of posts in forums and blogs all over the place. The problem is just figuring out what you need to search for.

The process goes something like this:

It was a bit of an involved process to get through. And at first when I installed the RC29 firmware and had to re-activate, I was afraid I wasn’t going to be able to do so without a TMobile SIM. Just a bit of APN hackery took care of that however. Phew! Now I have Latitude working in maps, and root access in the terminal. W00t! Back to developing now.