Building custom images
Motivation
This tutorial explains how you can build a completely customized OS image which can be used with:
- Emulators such as QEMU and VMware
- Laptops running in developer mode (see Activation and Developer Keys about running your xo in developer mode and Activated_Upgrade about installing OS images)
Prerequisites
The following procedure has been tested on a Fedora 8 x86_64, but should work just fine on Fedora 7 and on i386.
Any Linux distribution capable of running yum should be able to run Pilgrim, maybe with minor adjustments.
The intended audience of this document is an OS developer with some experience in rebuilding RPMs and managing yum repositories.
Preparation
FIXME: are there any prerequisite packages to install?
git clone git://dev.laptop.org/users/cscott/pilgrim cd pilgrim make sudo make install
Note: this will litter your system with pilgrim files, but you can clean it up later with make uninstall.
Prepare your custom repositories
Build your custom RPMs and place them in a directory accessible via http. It is recommended, but not necessary, to adopt the standard Fedora layout:
i386/os/ - i386 and noarch packages i386/debug/ - debuginfo packages source/ - src rpms
Create or update the RPM metadata information for your repositories:
createrepo i386/os createrepo i386/debug createrepo source
Pilgrim customization
Adding your yum repositories
Edit streams.d/olpc-development-yum-install.conf and append your yum repository (you only need the one containing the binary RPMs here). Mine looks like this:
[olpc-bernie] name=OLPC bernie - i386 baseurl=http://www.codewiz.org/pub/olpc-bernie/i386/os/ enabled=1 gpgcheck=0
Note that I've explicitly specified i386 because the $basearch variable would expand to x86_64 on my host.
If you provide the full set of OS packages in your repository, then you should remove the default repositories altogether.
Adding repositories for the target
Edit streams.d/olpc-development.stream, and find the line saying "Writing out configuration for OLPC yum repo". The repositories listed here will appear in /etc/yum.repos.d on the target and are only used when the image is booted on the target.
Add your yum repositories below the official ones.
This is what I do for xtest:
# keep this in sync with same repo defined in olpc-development-yum-install.conf cat <<EOF > $INSTALL_ROOT/etc/yum.repos.d/olpc-development.repo [olpc_development] name=OLPC development baseurl=http://koji.fedoraproject.org/static-repos/dist-olpc2-build-current/i386/ enabled=1 gpgcheck=0 EOF cat <<EOF > $INSTALL_ROOT/etc/yum.repos.d/olpc-bernie.repo [olpc-bernie] name=OLPC bernie - \$basearch baseurl=http://www.codewiz.org/pub/olpc-bernie/\$basearch/os/ enabled=1 gpgcheck=0 [olpc-bernie-debuginfo] name=OLPC bernie - \$basearch - Debug baseurl=http://www.codewiz.org/pub/olpc-bernie/\$basearch/debug/ enabled=0 gpgcheck=0 [olpc-bernie-source] name=OLPC bernie - Source baseurl=http://www.codewiz.org/pub/olpc-bernie/source/ enabled=0 gpgcheck=0 EOF
Adding and removing packages
The list of packages that will be installed is in streams.d/olpc-development.stream.
If your spec files are correct, you will only need to list the leaf packages here and yum will pull in all their dependencies automatically.
Further reading
Read README.olpc in the root directory of Pilgrim for further information.
The short story is:
(become root) ./pilgrim-autobuild --config-dir . --stream olpc-development --dest-dir .
If you're only interest in the jffs2 image, do:
./pilgrim-autobuild --config-dir . --stream olpc-development --dest-dir . --variant devel_jffs2
FIXME: once pilgrim builds an os.img, how to update an XO box to run it?
We want you!
Please send your patches to the [development mailing-list] for consideration. For large changes, just publish your git repository and provide the URL.