rooting the droid

[ link: rooting-g1 | tags: android g1 | updated: Fri, 15 Jan 2010 22:27:56 ]

In my continued quest to learn more and start hacking on the Android phones, I've recently rooted my Android based HTC Dream (aka Tmobile G1) phones.

I'll start by explain the terminology. There are two ways in which the phones can be unlocked:

so called rooting, which I describe in this post, involves replacing the bootloader so that the phone can use community generated firmware images, aka ROM's.
there is also unjailing or unlocking the phone so that it can be used with any SIM card on any GSM network; and I'll talk about that in due time.

WARNING: this may very well brick your phone! Read all the instructions here, and the links I provide. If you're still not discouraged, continue on :)

Before you proceed, I cannot stress the importance of following directions.

Here are five great reasons to root your Android phone, in case you were currious why anyone would.
I used the excellent Beginners Guide for Rooting your Android G1 to install Cupcake

UPDATE: The guide I used has been rewritten as How to root a T-Mobile G1 and myTouch 3G Android phone, it now has more details and screenshots.

UPDATE 2: Have not tried yet, but there is a new exploit that installs root on most recent firmware; see Root a T-Mobile myTouch 3G or G1 in 6 minutes and flash Cyanogen’s rom with Donut crumbs.

There are multiple write-ups like this one.
- I initially started with How-to- Root, Hack, and Flash your G1/Dream article posted on XDA developers forums.
  
  It was very accurate, but rather old. It does not use the root.apk application from the marketplace, which does most of the work for you.
- there is also How To Root Your T-Mobile G1 at the DroidProof blog. The write up has a YouTube video that maybe worth watching. It's based on the previous (old) method of rooting, but note that they forget to tell you start up telnetd first.
- another one is US/UK T-mobile HTC Dream G1 import/modding/jailbreak guide, but I have not looked at it. It has some links to different discussion threads that may help if you're stuck.
While I encourage you to follow the Beginners Guide, it basically boils down to this:
- downgrade to RC29 (which has that famed root exploit)
- gain root using root.apk (less typing: 2tu.us/nj0), or the manual method (see below)
- upgrade radio to v1.5 from HTC official site or googlecode.com mirror
- install custom image
Getting this far is a PITA, and takes an evening. After this, upgrading to any image is trivial: just copy it to update.zip on the flash card, boot holding the home key, and push the magic Alt-L + Alt-S combo.

Manual method:

after a clean boot of RC29...

type in <enter><enter>telnetd<enter>
install the telnet app from the market
download a new recovery.img (I am using Cyanogen's pimped out cm-recovery-1.4.img image)
download HardSPL/update.zip
copy the recovery.img and update.zip to the SDCARD
install the new recovery image...
- mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
- cd sdcard
- flash_image recovery recovery.img
- cat recovery.img > /system/recovery.img
- sync
shutdown, boot holding down HOME key
update...
- if using cm-recovery, when you get the menu, press alt-s
- if using standard recovery.img, when you see the triangle logo, press alt-l then alt-s
follow prompts, it will reboot a few times

you now have root. As before you need to install a community modded image:

first upgrade radio to v1.5 from HTC official site or googlecode.com mirror
- download, copy to SDCARD
- boot with HOME held
- run alt-s
then install a custom image. I recommend using CyanogenMod images.
- download, copy to SDCARD
- boot with HOME held
- run alt-s
NOTE: the CyanogenMod takes a long time to boot the first time.

Additional notes:

Here is a matrix of common ROMs
Here is an index of informative threads on xda-developers.com
With certain ROMs, future updates become even easier with Cyanogen updater or jfupdater.
Nandroid v2.0 - Full NAND backup and restore too
Recent CyanogenMod images also support apps on SD-card which is nice since the G1 has little internal flash.

To activate this feature partition your disk to have 1 big vfat partion and 1 smaller ext2/3/4 partition, boot to the cm-recovery image, enter the shell (alt-x), and type in apps2sd.
If you're stuck finding files, check here: Android development files
A community member going by alias cyanogen has some nice ROMs and tools:
How to use ext2/3/4 on the sdcard

Note that this is not required with cyanogen roms.
other interesting ROMs I didn't try...
- xROM
some pages that explain finer details further

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About

I am a Linux driver, kernel, and embedded software developer, currently working for Diablo Technologies Inc.