Re: Recipe for building an Ubuntu-12.04 root filesystem

Elvis Dowson

Hi Nicolas,

On Aug 21, 2013, at 4:50 AM, Nicolas Dechesne <nicolas.dechesne@...> wrote:

On Wed, Aug 21, 2013 at 2:24 AM, Elvis Dowson <elvis.dowson@...> wrote:
The Ubuntu and Linaro websites don’t document how the actual binary *.deb packages were created, the just document the process of assembling a rootfs from deb binary package feeds.

I’m aware that Yocto/OpenEmbedded can be used to generate *.deb packages, but what isn’t clear to me is how one can go about assembling a basic Ubuntu rootfs image that will boot into the Ubuntu Unity interface.

the short answer is that Ubuntu is not built with OE/Yocto, so you can't do that. OE/Yocto can help you build a filesystem for your target, that's what it's here for, but it won't generate an Ubuntu image.

it is correct that OE can generate .deb (or .rpm or .ipk) packages, but the generated packages won't be compatible on an Ubuntu system (you won't be able to install and satisfy dependencies). 

Ubuntu is a 'binary' based distribution. All Ubuntu packages are built on a centralized server (Launchpad), natively on 'actual' hardware. Ubuntu packages for ARM are indeed build on ARM build slaves hosted by Canonical. Launchpad offers 'PPA' (personal package archive) where users can upload their 'source package' and expect them to be built on Canonical build infrastructure. This is the mechanism that was by at Linaro to build ARM .deb packages. Note that since this is a binary distribution nobody rebuilds the entire image from scratch, instead packages are built individually whenever there is a change in the package, and the process of making an image (like Ubuntu daily image, or Linaro Ubuntu images) is just to 'assemble' existing binary .deb packages all together.

OE/Yocto is a set of 'tools' and recipes to let you create and customize your own distribution. You can create 'rebuild from scratch' distro with OE, or you can even create a 'binary' distribution if you need that.

Is there a way to replicate the build infrastructure locally in my environment? I have a quad core i.MX6 platform.

Best regards,

Elvis Dowson

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