A few weeks back I blogged on how to get Ubuntu installed through Crouton on a Chromebook. One of the biggest challenges I faced in setup was getting a USB 3G Modem to work. Below are my notes on how I managed to succeed.
Hacking Ubuntu on a Chromebook
In a few weeks time I’m going to be doing a bit of traveling for work and then a small holiday. As I will be hoping on and off planes and trains, I’m not really keen on taking my primary laptop as it is bulky and not really designed for travel.
After tossing up the pros and cons of tablets, netbooks, and ultrabooks I have bought a Acer C7 Google Chromebook and have managed to get Ubuntu 12.04 running inside a chroot environment. The whole process of getting Ubuntu installed has been much simpler than I was expecting.
For under $300 I now have basically a full lightweight system for travel on which I can watch videos, play music, edit documents, edit photos, and browse the web. While the basic Chrome OS operating system claims all these features, the reality is, it is extremely limited in what it is actually able to do.
Bumblebee, Optimus, Hybrid Graphics, and Ubuntu
For the last year or so I have been struggling with my laptop overheating under Ubuntu. Upon upgrading to the latest beta of Ubuntu 12.10 I have managed to completely solve the heating problem and as a result increased my battery life by more than an hour.
Two different problems have caused the heating problem. The first, a power-regression bug on i7 processors was resolved in Ubuntu 12.04 with an updated kernel.
The second is caused by the Nvidia Optimus Hybrid Graphics card in my laptop not being properly controlled by Ubuntu. Problems with Hybrid Graphics under linux are well documented and there are quite a few different “solutions” available, however, I have been unable to get any to work until now.
A few months back I installed the Bumblebee project, and despite the packages successfully installing, the hybrid graphics card never worked and battery life remained terrible.
Upon upgrading to the latest Ubuntu beta I noticed a problem in the logs during the install of one of the bumblebee packages: bbswitch-dkms
The package would “successfully” install, however, the terminal output would show that the kernel module was never built.
The problem lies in missing kernel header packages. While the Ubuntu Wiki pages do not detail any requirement for the installation of kernel headers other sites do, however, these other sites only focus on the kernel headers for the currently installed kernel. And, if you update the kernel without new headers, it is possible that the kernel module will no longer work and the overheating problem will return.
This is how I setup my system so that I would always have the latest official Ubuntu kernel and headers with bumblebee working:
1. Install the linux-headers-generic package:
sudo apt-get install linux-headers-generic
2. Setup the Bumblebee PPA:
sudo add-apt-repository ppa:bumblebee/stable
3. Update the package information:
sudo apt-get update
4. Install the bbswitch-dkms package:
sudo apt-get install bbswitch-dkms
Before moving on make sure that the output from the above command shows that the module was successfully installed.
5. Install the rest of Bumblebee:
sudo apt-get install bumblebee bumblebee-nvidia
6. Restart and then test if Bumblebee is working:
The second command runs the opengl test using the Optimus graphics card and the output in terminal of the FPS should be much greater than the previous command. Bumblebee should now be successfully installed and you should notice a large decrease in CPU heat and an increase in battery life.
In my opinion during the install of the bbswitch-dkms package a check should be made for the required kernel headers to build the kernel module, if the packages aren’t found a proper error and suggested solution, such as the installation of the headers package should be suggested. A silent fail that keeps the rest of the installation running only provides the end user that false hope that things are working fine.
Recovering from Grub Rescue after upgrading to Ubuntu 11.04
Over the weekend I upgraded one of my computers to the new beta of Ubuntu. Upon restarting the computer I got dumped into grub-rescue with the message missing-xputs. Part of the cause of this was having Adobe CS3 installed in my dual boot with Windows 7.
When you install Adobe products a little DRM program called FlexNet gets installed into your boot sector which is also where grub resides. When grub is upgraded along with Ubuntu it flicks a warning about the FlexNet being in the sector but then continues to install. However, when you restart grub will not run and will be unable to boot your system into either Ubuntu or Windows.Read more