[RFC PATCH V2 2/2] kbuild: dtbs_install: new make target

[Russell King - ARM Linux]

On Tue, Nov 19, 2013 at 11:42:17AM -0700, Stephen Warren wrote:
> On 11/19/2013 05:28 AM, Russell King - ARM Linux wrote:
> > On Mon, Nov 18, 2013 at 03:46:32PM -0700, Stephen Warren wrote:
> >> Again, the point is not that it's hard to write the script. As you
> >> demonstrated, it's easy. The problem is that then, everybody has to do
> >> something different for Tegra, forever. No matter how small the actual
> >> cost of doing it is, it's still non-scalable to require that everyone
> >> know about this special case. I'm not convinced the issue would be
> >> isolated to Tegra either.
> > 
> > That's why there's the facility to allow an override to the script,
> > just like there's the facility to override the default script when
> > running "make install".
> 
> Again, you are completely missing the point about that not scaling at all.

No I'm not.  What you're looking for is perfection.  Perfection is something
we can't have here - we can have "good enough".

Look, the problem is very simple: we have a bunch of DT descriptions in
the kernel, which we build to a blob.  We don't want distributions poking
around in the kernel source tree to retrieve these blobs, so we provide
a way to install them somewhere.

The installation should just copy the blobs to a path in the filesystem
_or_ allow a distro to hook into the installation process, just like we
provide for the installation of the zImage.  That is our job done.  We
should do *nothing* more.

If we start doing more than that, we're getting into the realms of
distribution policy, and that's something we should not be involved in.

This is precisely the reason why we don't get involved with working out
what steps are needed to install a kernel zImage onto a target: that
is _not_ the kernel's job to work out that you may need to package it
up and maybe copy it over to a TFTP server, or maybe copy it onto a SD
card, or maybe place it in /boot and do a certain number of other
steps.

All that the kernel build's job here is to provide the results of the
kernel build.  It is not about working out which DT blob is right for
any particular platform.