This project aims to add a package manager to ChromeOS running on Cr-48. At present there are only two ways to install native Linux applications:

1. Build a ChromiumOS image and customize its packages,
2. Install a real Linux distro.

The first approach is powerful but inflexible. After you've built the image and boot the computer, you can no longer add new programs due to ChromeOS' security policy. ChromeOS mounts writable partions as non-executable, and executable partitions as non-writable. Did I mention setting up the build environment is intimidating too?

The second approach is somewhat tedious, and throws all the ChromeOS goodness away.

Since I am new to this ChromeOS thing, and I've been away from Debian for a while, I need your help to make this project succeed.

I chose to port dpkg/apt from Ubuntu Karmic, because its glibc 2.10.1 matches the version on ChromeOS. Using any rolling distro on top of ChromeOS is impossible, although I like Debian and Arch so much more.

# Turn off rootfs verification
sudo /usr/share/vboot/bin/make_dev_ssd.sh --remove_rootfs_verification
sudo reboot

sudo mount -o remount,rw /

# Remount /var exec because dpkg wants to execute scripts extracted from .deb files
# This command must be run after each reboot
sudo mount -o remount,exec /var

# Download dpkg's data.tar.gz from Ubuntu Karmic, extract it to / to get the dpkg binary
cd /; sudo tar zxf /path/to/data.tar.gz

# Create files needed by dpkg
sudo touch /var/lib/dpkg/status /var/lib/dpkg/available

# Copy ldconfig and update-rc.d, they are needed by dpkg

# Satisfy dpkg's dependencies by installing fake debs

# Install dpkg.deb for real

# Install apt.deb and copy /etc/apt

To download a .deb file, run sudo apt-get -d install --reinstall foo and you'll find /var/cache/apt/archives/foo*.deb.

Before you apt-get install a program, double check if it's pulling in any dependency that will overwrite existing files. Doing so may break the login manager, the browser, or any other critical program. I've created a simple tool TestPkg:

$ ./tools/TestPkg ocaml
["camlp4","ledit","libncurses5-dev","libpthread-stubs0","libpthread-stubs0-dev","libx11-dev","libxau-dev","libxcb1-dev","libxdmcp-dev","ocaml-base","ocaml-base-nox","ocaml-interp","ocaml-nox","x11proto-core-dev","x11proto-input-dev","x11proto-kb-dev","xtrans-dev"]

I'll be updating the wiki for compatible programs.

Modifying your root file system will most likely disable ChromeOS' auto update. Overwriting existing libraries may make your system fail to start. But good thing is you're always able to restore to factory setting.

I've created a simple tool FakePkg that automates the process of generating fake packages. Simply add the name of the package to fake-debs/build-debs.sh. If you've tested a fake package can be safely added, please send me a pull request and explain what real package was safely installed that requires the fake package you added.

You're also welcome to improve my simple tools, or report which packages can be safely installed.

I admit my approach is an ugly hack and if you know a better solution please let me know.

ChromiumOS manages packages based on Gentoo's portage system. Its overlay can be viewed on the web and cloned from http://git.chromium.org/git/chromiumos-overlay. chromeos/scripts/setup_board sets the version of the system packages such as glibc.

To get an overview of the packages, we can run ls * at the top level. The structure resembles Gentoo a lot, except that many packages are removed. In fact I believe the ebuilds are taken from Gentoo directly. ChromeOS-specific ebuilds are found under chromeos-base/.

When you emerge the virtual package chromeos (there are some variants like chromeos-dev and chromeos-factoryinstall), image building starts and dependencies are pulled in. Unfortunately, while the package manager (sys-apps/portage) and the toolchain (sys-devel/) are in the portage, they don't get built into the image.

The stock system on cr-48 seems to be built from ChromiumOS' 0.9.128.B branch (B for beta?), with some changes (some dev packages removed, and some proprietary drivers added).

Another important piece of code is the verified bootloader and the disk management utilities, available via git at http://git.chromium.org/git/vboot_reference.

For more information, see http://www.chromium.org/chromium-os/developer-guide
http://www.chromium.org/tips-and-tricks-for-chromium-os-developers
http://www.chromium.org/chromium-os/how-tos-and-troubleshooting
http://www.chromium.org/chromium-os/building-chromium-os/directory-structure

1. Port more packages
2. Write scripts for auto installation
3. Improve the workflow