HOWTO: Gingerbread official on your Nexus One

[Skythe]

(Original post via my blog)

Hi guys,

Here's the steps I followed to upgrade from my unrooted STOCK Vodafone (AU) firmware to Gingerbread. This is from the latest Vodafone firmware. Disclaimer; if this process bricks your phone it's not my responsibility. You do so at your own risk (not likely but covering my backside anyway!).

1) You need to downgrade to an older, Google-specific firmware (FRG33). Download this from here

2) Extract it, and you will find another .zip file, rename this to passimg.zip and copy it to the root of your phones SD card.

3) Power down the phone, hold Vol- and turn it on, it will fire up into HBOOT, and detect the passimg file on the SD card. You'll get a yes/no prompt to install it, so pick yes and let it do it's thing for a few minutes. All being well (as in it is OK with downgrading) you can then reboot. You are now using the official Google Firmware, rather than the Vodafone firmware.

Next is a long series of steps of upgrading from version to version. Each upgrade (process) is the same as previous one, so repeat steps 1 through to 8.

#TROUBLESHOOTING
- IF you run into any problems, check that you are upgrading from the right version/file (especially if you are getting error 7). If you skip any version or step it will likely produce an error. Check in Settings > About Phone > Build Number if you are unsure of your version.
- Also, make sure if you have extensions hidden in windows that you aren't renaming each file to update.zip.zip (as it won't pick up the update.zip if it's called update.zip.zip).


#NOTES
- When I followed this process, I did not get any Over The Air updates. IF you do happen to get OTA updates, then you might be able to ignore certain steps (depending on what your OTA upgrades to).
== File list (Repeat steps 1 - 8 for each of these)
FRG33 > FRG83
FRG83 > FRG83D
FRG83D > FRG83G
FRG83G > GRI40 (Gingerbread)

== Steps (Repeat once per each file)
1) Place the file on the root of your SD card
2) Rename it to update.zip
3) Power the phone off, hold the trackball button and power on.
4) You’ll be booted into a white screen with three Android robots on skateboards. Select “Bootloader.”
5) On the next screen, select “Recovery.”
6) Your phone will reboot, giving you a picture of the Android robot and an exclamation point inside a triangle. Now press the power button and volume up button at the same time. It could take a couple of tries.
7) Now (using the trackball this time) choose “Apply sdcard:update.zip” and let things run their course.
8) Reboot, then repeat all these steps to upgrade to the new version, until you finally have Gingerbread.

Please let me know if there's any errors in the above instructions, haven't exactly got 2 phones to test myself