[AT&T Samsung Galaxy S II SGH-I777] monsieurtalbot:
http://xdaforums.com/showthread.php?t=1223128

^Original thread in the I9100 forum by: Jdouce^

Should work on SGH-i777 as well... Just thought I'd share.

(edit) TESTED -and this does in fact work. You can even access the Linux UI via any VNC viewer as long as you're on the same network as your phone or tethered. I have added to the tutorial below to specify. You can also access your Android file system and access everything via this image. I leave you to drool. :D

***(edit 2) If you can't figure it out, I have found Ubuntu installers available on the Market, but they require you to use your internal storage space. This version can be installed on either internal OR external memory. The performance and UI of this version is better too. The versions available via app are not optimized as well as this one. =) - Just know that there is a foolproof way to accomplish this if you can't read directions... Just search "ubuntu" in the Market.

-----Original Post (with clarifications and additions by Monsieurtalbot)-----

DO NOT UPDATE UBUNTU TO 11.04/11.10 IT'S HORRIBLY SLOW AND BREAKS THE .IMG! -

YOU CAN HOWEVER INSTALL ANY OTHER UPDATES AND APPS JUST FINE.

1. Download the Ubuntu files (2 part .rar)

File sizes should be;

Part1 = 900 MB

Part2 = 572 MB

Part1 Download

Part2 Download

2. Open Part1 and unrar the folder and copy to your internal sdcard (/sdcard) OR external SD card (/sdcard/external_sd) - this unrar's both parts.

**there should be 2 files - "ubuntu.img" & "ubuntu.sh" - these go into an "ubuntu" folder in one of these locations.

3. Open the Market (now Play Store) - download and install terminal emulator and Android VNC viewer - Both free.

4. Open Terminal emulator. Depending on where you copied the files mentioned in step 1/2, enter ONE of the following sets of commands.

**Remember. Commands and directories are case sensitive, so make sure everything (including the file names and folder title) is lowercase to make it work.

(if you copied to the INTERNAL sdcard)

cd /sdcard/ubuntu
su
sh ubuntu.sh

(if you copied to the EXTERNAL sdcard)

cd /sdcard/external_sd/ubuntu
su
sh ubuntu.sh

press home - and DO NOT CLOSE the terminal. You need to keep this shell open.

(you can also get an app called "Script Manager" from the Play Store to make re-entering these commands simple later.)

5. Open the Android VNC viewer and connect using the following settings.

address: localhost
port: 5900
password: ubuntu
set color to 24 bit

You can also use a VNC viewer on a PC or tablet to access the Linux UI, and use the keyboard and mouse using your favorite VNC viewer (I was using TightVNC on Windows) with the following settings while both devices are connected to the same WIFI (or tethered to the phone)

address: (your phone's local IP address here)
port: 5900
password: ubuntu
set color to 24 bit

VOILA - You now have Ubuntu 10.10 running on your device.

6. WHEN FINISHED- Shut down Ubuntu in the UI, disconnect VNC, then in the Terminal Shell type: "exit" without quotes and press <enter> to clean up the Linux image mount for next boot. Failure to do this may result in a corrupt install. Once you see a "#" with no commands, it is safe to close the terminal window.

_______________________________________________________

Whats Working?

USB Host - Using adapter cable available online to attach keyboard, mouse, or Flash drives.

WiFi

3G

Browsers- any of them... I suggest Chromium over Firefox, but they both do the trick.

Installing Applications

Updating (NOT UPGRADING to 11.04/.10)

Its pretty much working, let the OP (linked above) know if you have issues.

***HELP! UBUNTU WORKED BEFORE, BUT NOW IT WON'T BOOT-

The image creates a new folder to mount the Linux files at "data/local/mnt"... Connecting USB to a PC, unmounting the storage device the image is stored to, a forced shut down, or unexpected occurance in the shut down procedure CAN cause this. It's due to "stuck" files in that directory. -Attempt to clear the contents of this folder - followed by a reboot if you have any issues. You can do this using root explorer, or with the following terminal commands.

su
rm r /data/local/mnt

GOOD LUCK!

-----END OF ORIGINAL POST-----