How to install CyanogenMod 4.1.99 on your G1 Android Phone

This tutorial will take you every step of the way through installing CyanogenMod 4.1.99 on your G1 phone – the first “legal” version of CyanogenMod (after Google sent cyanogen a cease and desist).

Please note: This was initially published back in 2009 and is now considered out of date. As such, this guide should be considered a ‘historical archive’ rather than something to use in 2021.

The steps outlined in this tutorial were gathered from the official announcement of 4.1.99 on the xda-developers forum. For more information on 4.1.99, see this thread.

Warning: though unlikely, it probably technically possible that following the steps outlined in this tutorial may result in your phone no longer working. Not following these steps in the right order, would increase those chances. With all of that said, it’s very unlikely that anything bad will happen.

See the link at the end of this tutorial, once you’ve completed it, to upgrade to CyanogenMod 4.1.999.

  1. Start out by making sure that you have Cyanogen Recovery 1.4 installed on your G1. If you do not, follow steps 6-20 in this tutorial (Update: link no longer works).
  2. Download the file (the Recovery image, not the Radio or System image) from the Android Developer Center (Update: link no longer works). Then download the file (Update: link no longer works). Copy both files to your Android’s SD card. Note: I copied them to my phone in OS X (as illustrated below) – you can use Windows or an Android FTP client – it doesn’t matter. As long as they’re copied to the root of your SD card, you’ll be fine.
  3. Now power off your phone. Hold down the Home button when powering it back on, so that you enter recovery mode. Select nandroid v2.2 backup and click your trackball.
  4. This will perform a backup, just in case it’s needed.
  5. Once the backup has completed, select apple any zip from sd and click the trackball.
  6. Select signed-dream_devphone_us… and again, click the trackball.
  7. You’ll be notified that you’re going to install a new image. Click the Home button on your device to confirm this action.
  8. The new image will now install.
  9. Once the installation process has completed, you’ll be taken back to the recovery screen. DO NOT reboot your device at this point. Instead, once again select apply any zip from sd.
  10. This time, select update-cm-4.1.99-signed and click the trackball.
  11. As with the previous image installation, click the Home button on your phone to confirm.
  12. This will install CyanogenMod 4.1.99 on your phone.
  13. Once that installation has finished, you’ll be presented with the recovery mode screen, again. This time, select go to console.
  14. Click the enter key on your keyboard
  15. You should now be presented with a command prompt. At the prompt, enter fix_permissions and click the enter key on your keyboard.
  16. A bunch of text will fly by. You might notice that some of the text says No such file or directory. This is normal, depending on how your phone was previously set up.
  17. Once you’re back at a prompt (the text has stopped scrolling) – type the word reboot and click the enter key on your keyboard. Your phone will now restart.
  18. Your providers ‘boot’ screen (in my case T-Mobile) might be displayed for slightly longer than normal. Don’t worry. Eventually the CyanogenMod Android logo will appear – and it too may be displayed for longer than normal. Again, don’t worry.
  19. Once your phone finishes starting up, select Settings from your Applications, and then About phone from the Settings list. In the Mod version section it should say CyanogenMod-4.1.99. That confirms that you’ve successfully installed CyanogenMod 4.1.99. Congratulations! You now have a completely legal modded G1.
  20. Launch some of the apps on your device. Confirm that the proprietary programs like Gmail, YouTube, Google Maps etc all work. If you experience any issues, try asking for help on this thread at the xda-developers forum. Be sure to include as much and as specific information as possible in order to receive a timely reply.
  21. Once you’ve finished upgrading to 4.1.99, you can upgrade to version 4.1.999 by following this tutorial. The process is much faster (fewer steps) – but again, you must have completed the steps in this tutorial first.

If this article helped you, I'd be grateful if you could share it on your preferred social network - it helps me a lot. If you're feeling particularly generous, you could buy me a coffee and I'd be super grateful :)

buy a coffee for

Home » Mobile Phones » Android » How to install CyanogenMod 4.1.99 on your G1 Android Phone

31 thoughts on “How to install CyanogenMod 4.1.99 on your G1 Android Phone”

  1. Is there any way to install this mod without losing all the installed/purchased apps and settings? I’ve had this for a few months already and there is quite a bit on the phone that I would not like to have to reinstall/configure. Will apps2sd or mybackup (rerware) help?

  2. Hi-

    I’m on a TMobile G1.

    I was running cm 4.0.4 and today I got a bug where my home button doesn’t work anymore and the phone doesn’t lock.

    I figure this may have happened because I updated several apps at once and also set up the lock pattern preferences.

    Anyway, today, I updated to 4.2.1 and the same home key fail and unlock problem exists.

    Did I copy this bug to the new mod when I used nandroid backup?

    Is there any way to re-install this without running nandroid? I have my apps and contacts, etc backed up already with backup for root users.

    Or, can I empty the contents of the nandroid folder on my SD card to install a bug-free cm4.2.1?

    Thanks for any help!

  3. @Ummm,
    Yes! But if you follow ALL instructions perfectly, & aftr u get apps2sd installed, it’l be your last time… enjoy the World of Modding

  4. @AndroidUsr
    Thanks for the tips. Before I saw them, I had searched for the same issue (desktop icons disappearing) and found someone posting elsewhere with the same issue. I contacted him to find out if he had resolved the issue and he had and told me what to do, which was to boot into recovery and select “repair ext filesystems”. That did the trick!

  5. @BradO,
    I suggest this:
    > Open Terminal (not the Console in Recovery)
    > type: fix_permissions (this WILL take a while, be patient)
    > reboot

    If that doesn’t correct the issue:
    > open Terminal
    > type: fs_upgrade

    If that fails; I suspect the SD card is bad. Or, the File system on the Ext partition is corrupt due to the SD card. fs_upgrade SHOULD’VE repaired if it’s a Software issue.
    NOT all SD cards are made the same. SanDisk & Transcend are reputable SD Co’s. Try a new one…
    If that fails, post results AFTER you’ve tried the above


  6. I’ve encountered an issue that I haven’t seen mentioned yet. I followed all of the steps to get myself up to speed with 4.1.999 on Friday. Everything went smoothly, running well, no problems. UNTIL…two days ago. All of the sudden, at least two times a day, my desktop icons completely disappear. Once I reboot, they’re back, but after 12 hours or so of use, they’re once again gone. Any idea what may be causing this?

  7. These steps worked perfectly for me. I swapped steps 1 and 2 around so I would already have the zips on my SD before turning off my phone.

    For anyone interested I have an Australian HTC Dream (Optus) that I had already rooted (ages ago) with JF’s mod and Hard SPL.

  8. Just made the sdcard partition with ext3 and swap. My G1 reloaded great now, didnt need to wipe or reflash to 4.1.99

    Thanks AndroidUsr, thanks all.

    G1 CyanogenMod 4.1.999 System Recovery 1.4

  9. Kenneth Wilson,
    Good! We’re getting somewhere w/ the permissions, but plz refresh my memory w/ your issue? Mondays r long & so is this thread :) thx

  10. Actually I don’t type su. I go to console. And is says press enter. I do and you are correct the “#” sign does show and that is when I type “fix_permissions” and lots of words flash by then another “#” apears. I then type reboot. It reboots and problem not solved

  11. Kenneth Wilson,
    When in Console, I’m assuming you’re hitting the ENTER key prior to typing: su?
    By hitting the ENTER key, you bring up a ‘#’ prompt. Thats when to typr: fix_permissions… FYI

  12. Kenneth Wilson,
    Super Usr/Root or su, are identical. But, one is a Command-su, and the other is an Administrative Power. Administrator is an analogue if you come from the *indows World.

    > reboot into Recovery – Home+Power
    > Console (Alt+X)
    > type: fix_permissions

    post back w/ results plz

  13. Hey AndroidUser, I tried to run fix_permissions on su but that didn’t work either. I still can open the market or use gmail. Super user us when you select “go to console” with the trackball under the reboot menu right? And I do have root access so a little confused. Thanks hope to hear from you soon

  14. I was having all the “slow down” problems and more. But I’ve got it now. This is what I did. It had to do with ext2.
    1.) I reverted back to 4.1.99. Wiped.
    2.) Went to .
    Read through to part iii – convert ext2 to ext3/ext4:
    Goto consule and run
    3.) rebooted
    4.) Flashed 4.1.999, reboot
    5.) its fast now. no delays at all

    hope this saves a few hours for you.

  15. @androidusr
    Thanks followed the steps and I was able to fix permissions. Now running .999 and is very fast and responsive. Thanks a lot.

  16. To All who are having fix permissions Issues; Some of your issues can arise from having a corrupted EXT partition on your SD card… So,
    > re-boot into Console – Home+Power
    > Alt+X or scroll to Console
    > hit the ENTER key
    > type: fs_fsck
    > type: reboot
    > hold HOME key while re-booting
    > go back to Console
    > ENTER key
    > type: fix_permissions (let it do its thing…)
    > type: reboot
    post back if no joy

  17. Process above worked perfect for me….you need to have the proper Recovery Image installed and active or it won’t work at all….It did take quite a while for the system to boot after the update but not an hour like some suggest.

    I’d restore the Backup you made before the flash and try again….restoring the backup will return you to the exact environment you had prior to updating or trying to update to 4.1.99.


  18. Zecht & Guy,

    > Open Terminal
    > type: su
    > choose ALLOW or ALLOW ALWAYS
    > type: reboot
    > hold HOME key while re-booting (or, HOME+POWER)
    > sroll down to Console, select.
    > Hit ENTER key
    > type: fix_permissions
    if no error;
    > type: reboot
    post w/ results if no joy

  19. Joseph: I believe the procedure is the same, so regardless of what you’ve got on there at the moment, you start from the Dream devphone recovery image, then slap Cyanogen Mod on top of that.

  20. Ian – yup, looks like. sadly it looks like the permissions to use the touch keyboard don’t work.. so you can’t load the keyboard to set the permissions.. don’t really know what to do at this point.. glad i ran a backup though.

    Cyanogen – we need a fix for the MyTouch

  21. The recovery flasher is installed and i have 400+ megs free on my sd card but when I press the Backup Recovery Image button I get the error “Backup FAILED”

  22. I can’t get the recovery flasher to work. I get the error “backup failed”. Is this because I already have donut?

  23. Jeremy – at this point I’m honestly not sure what the problem might be. Are you coming from a previous version of CyanogenMod or an unmodded phone?

    Confused – it shouldn’t matter that you already have Donut. Do you have the recovery flasher installed, and it won’t update the HTC image, or it flat out won’t install (the Recovery Flasher itself)?

  24. Thank you for making this great tutorial! Cyanogen should’ve worked with you, and included this in his official thread at xda-developers — probably wouldn’t have had _half_ the problems that he’s been complaining about lately.

    Not that I blame him, of course, but you have to admit that even for someone technically minded, the “instructions” on xda-developers can be a goddamed mess.

Leave a Comment

Your email address will not be published.