Attention!

This update only seems to work for the developer version of the G1. If you have any other version of the phone than the developer version, please contact your provider for a system update.

Seriously: If you are not sure, that you know that you have the right version of the phone and/or the correct files then DO NOT try to update. Your phone may freeze. I am getting a lot of emails and comments in this post of people who froze their phone. The following description worked fine for me, but it does not mean that it works for everybody else. I also can give NO support to any difficulties that may come up during this update procedure (I neither have time nor the technical expertise to do so).

I was brave enough ;-) to upgrade my G1 today from the old firmware version 1.0 to 1.5. The following steps describe how I made the upgrade.

  1. Go to http://www.htc.com/www/support/android/adp.html and download the radio image (ota-radio-2_22_19_26I.zip) as well as the recovery image (signed-dream_devphone-ota-147201.zip) for the firmware update you want to upgrade to. In this case 1.5
  2. Rename the “ota-radio-2_22_19_26I.zip” to “update.zip”
  3. Plug your G1 into your computer and mount as a USB mass storage device using your USB cable
  4. Copy the “update.zip” onto your SD card in your G1
  5. Unmount the USB mass storage device and than disconnect the phone
  6. Shut off the G1
  7. Start up the G1 by pressing the “home” and the “power on/off” button at the same time (and hold) until a triangle with a “!” appears
  8. Flip the keyboard and press “ALT” and “l” (lower case “L”)
  9. A screen appears with a menu
  10. Press “Alt” and “s” to apply the “update.zip” on the SD card
  11. If the installation is finished (it tells you when), press the “home” and the “back” button and release them again to reboot the system
  12. If the system has rebooted, mount the device as USB mass storage device again, by using your USB cable
  13. Delete the update.zip from your G1 SD card
  14. Rename the “signed-dream_devphone-ota-147201.zip” to “update.zip” and copy this onto your SD card
  15. Unmount your USB mass storage device and disconnect the G1 from your computer
  16. Power off the G1 by pressing the “power on/off” button
  17. Start up by pressing the “home” and the “power on/off” button at the same time (and hold) until a triangle with a “!” appears
  18. Flip the keyboard and press “Alt” and “l” (lower case “L”)
  19. A screen appears with a menu
  20. Press “Alt” and “s” to apply the “update.zip” on the SD card
  21. If the installation is finished (it tells you when), press the “home” and the “back” button and release them again to reboot the system

The last initial boot of the 1.5 firmware might take a while. But as soon as you get back to your start screen you are finished. You are now free to delete the “update.zip” from your SD card.

Although I tried this update process with my own phone and it worked perfectly there, I do not guarantee that this procedure works with every G1. So please be aware if you upgrade your phone and always backup your data!