Now that you have downgraded your radio to RC29, you can exploit a security hole in the system to enable root access. This process is relatively straight forward, but requires careful typing on your G1 keyboard. By following these directions, you will be well on your way to a custom G1 ROM.
This part of the process contains two main parts. In the first part, you will install a telnet application and manually configure root access. In the second part, you will install a new recovery image to make loading ROMs faster and easier. Cyanogen's recovery image is excellent. However, there are frequent changes, so always adjust the file names in the following steps to reflect the actual file you have.
Downloading the Image and Rooting Your Phone
Download Cyanogen's recovery image cm-recovery-1.4.img.
- Copy the file to your SD card's root.
- Search the Android Market for Telnet.
- Install the Telnet app.
- Go to your home screen.
- Slide open the keyboard.
Press Enter once, then again after a moment.
Type "telnetd" on the keyboard in lower case. Android 1.0 will open your dialer to your contact list while you are typing. This is normal.
Press Enter again.
- Launch the Telnet app.
- Connect to the server using port 23, which is default.
Type "mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system" to make the system folder writeable.
Type "cd sdcard" to change to the sdcard directory.
Type "flash_image recovery cm-recovery-1.4.img" This replaces your existing recovery image with the new Cyanogen recovery image.
- cat cm-recovery-1.4.img > /system/recovery.img (copies the cm-recovery image to your system directory)
Verify the Recovery Image
As with any step in this process, it is very important to verify that the software has installed correctly. To verify that the recovery image has been correctly installed, do the following:
- Power off your phone.
- Turn the phone back on while holding down the Home key.
- You should see the new Cyanogen recovery screen. The Cyanogen recovery screen for 1.4 reads "Android System Recovery <2>" across the top and "Build: CyanogenMod v1.4 + JF" across the bottom.
This new recovery image will allow you to copy and install any of the various custom ROMs from your SD card to your phone. It is important to remember that installing a new ROM will always remove any Android apps. You will always need to re-install your apps when switching ROMs.
Rooting & Flashing Your Android Based T-Mobile G1 With Google
Rooting your G1 and installing a modified ROM, like those from Cyanogen, Jesusfreke or Haykuro, will enable many features not included in the native T-Mobile build. A rooted phone also gives you access to a number of applications, like screen capture apps.
- Rooting Your Android Based T-Mobile G1: Part 1, Downgrading Your Radio
- Rooting Your Android Based T-Mobile G1: Part 2, Rooting & New Recovery Image
- Rooting Your Android Based T-Mobile G1: Part 3, Upgrading the Radio, SPL, and ROM