[Buildroot] [PATCH 1/5] Makefile: add media image generation

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Yann E. MORIN,

On Thu, 19 Mar 2015 09:44:35 +0100, Yann E. MORIN wrote:

> However, what I wonder about, is that all those defconfigs rely on the
> image already generated by Buildroot, and I fail to see how one would
> write a mutli-partition genimage config file.
> 
> Furthermore, I've read the genimage docs (a mere README, far from being
> complete), and it does not look obvious to me.
> 
> Also, rather than letting Buildroot build the filesystem images and then
> aggregate that with genimage, it would be meuch more interesting (IMHO)
> to provide an example that lets genimage do the filesystem. That would
> be a good example on how to do it.

Well, the boot.vfat image in the raspberry pi example is a good
illustration of this: the FAT filesystem image is not created by
Buildroot, but by genimage itself.

> Also, in the case of multiple partitions, I wonder how /etc/fstab is
> updated (since the current examples only use a pre-generated filesystem
> image, they can't update fstab).

Using a post-build script ?

> It might even be interesting to have an example (e.g. in the manual or
> somewhere else...) with a more complex setup, like a multi-partition
> setup where parts are inherited from Buildroot (the rootfs) and others
> are generated by genimage, or whatever seemingly complex setup we can
> come up with...

Yes, I agree it would be interesting to have more complicated cases
covered in the Buildroot manual.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com