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Getting Ubuntu armel/armhf Rootfs in Ubuntu 12.04

I’ve recently upgraded to Ubuntu 12.04 and this is a great operating system. However, if you do some arm development and expect to be able to install cross libraries (armel/armhf) or easily generate an arm rootfs using the tools you’ve been used to, you’ll be disappointed.

In Ubuntu 11.10 (Oneiric), I used xapt and dpkg-cross to retrieve armel libraries, but it’s broken for Ubuntu 12.04, at least on my system. I’ve been told to switch to multiarch because this will be how it’s done from now on. But I soon discovered this is work in progress as quite a few packages are not multiarched yet including python.

Ubuntu developers also decided to remove rootstock (which makes sense since xapt/dpkg-cross will be deprecated), so if you want to generate a rootfs the “gool ol'” way (which won’t be supported much longer), you’d have to install an Oneric chroot to run rootstock, or copy the rootstock script in Pangolin.

There are 2 ways to get an Ubuntu rootfs now:

  1. Download the official Ubuntu-Core 12.04  armel or armhf image (a minimal image without X). This is the recommend method, especially if stability is the most important for you, or if you need armel.
  2. Download one of the monthly Linaro armhf releases. That’s the image you’ll want if you need the latest developments. This version should work just fine, but is not as thoroughly tested as the official Ubuntu release.

If you select method 1, you’ll then need to install the needed packages with apt-get. In case your target board only support Wi-Fi (i.e. no Ethernet), you may have to download the required packages (e.g. wireless-tools, wpa-supplicant…) and install them manually (TBC).

To get the armel rootfs:

wget http://cdimage.ubuntu.com/ubuntu-core/releases/12.04/release/ubuntu-core-12.04-core-armel.tar.gz

and the armhf roofs:

wget http://cdimage.ubuntu.com/ubuntu-core/releases/12.04/release/ubuntu-core-12.04-core-armhf.tar.gz

Several Ubuntu rootfs are available with the monthly Linaro releases:

You can get the latest images monthly from http://www.linaro.org/downloads usually released around the 25th.

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