[PATCH] kexec:arm: support zImage with appended device tree

[Dave Young]

On 07/03/17 at 05:41pm, Russell King wrote:
> On Tue, Jun 27, 2017 at 06:51:50PM +0900, Hoeun Ryu wrote:
> > > What about the initrd?  Do you want to append that as well?
> > 
> > I have thought of it.
> > I think It would be better to have it.
> > But I think this is the first step to do so.
> 
> That is something we don't support with the kernel, and would be insane
> to do so - it would mean that the very dumb decompressor would have
> to relocate not only the dtb image, but also the initrd image to
> some other part of memory.  It moves the appended dtb image along with
> the rest of the zImage as one complete blob, but that doesn't work
> so well for an appended initrd.  It will also be rather slow.
> 
> So I'd like to continue my discouragement of this entire approach and
> say that kexec-tools should *not* add support for an appended DTB nor
> an appended initrd.

I also agree that we'd better not adding this in kexec-tools, --dtb
works well, the appended dtb does not gain much but it introduces more
code to maintain.

> 
> The kernel build process gives you the kernel image and dtb file.
> The appended-dtb image support that we have in the kernel is for
> backwards compatibility with non-DT aware boot loaders that only
> know how to deal with one or two images at boot time.
> 
> -- 
> Russell King

Thanks
Dave