To update your Google G1 phone (mine is an Android developer unlocked phone) to Android 1.6 (Donut), I did the following.
- Download and unpack the Android SDK for Mac OS X from http://developer.android.com/sdk/index.html
- Download the Android 1.6 Radio and System Images from http://developer.htc.com/adp.html
- Reboot phone with USB connected
- Update the Device Radio Firmware
- Confirm devices with $ adb devices This step drove me crazy because it would list no devices. It ended up being a faulty (and new) USB cable. When your phone is connected to USB, it will give you a notification, and usb icon on phone top menu.
- Copy Radio image
- Reboot in recovery mode and follow instructions
- Download the fastboot for Mac OS X at http://developer.htc.com/adp.html
- Flash the System Image Package to the Device as per instructions
The instructions say to reboot, but in my case it rebooted automatically after the fastboot update.
The problem after reboot was I was unable to sign in to google servers the first time. At G1 Dev Phone won’t connect to Google servers with valid SIM card I added the necessary AT&T/Cingular APN via details at http://modmyi.com/wiki/index.php/Carrier_APN_Settings.
I could then go Settings | Data synchronization and continue the Google registration process.