[U-Boot] [RFC PATCH] arm: bootm: Boot kernel with U-Boot's FDT blob

[Mark Rutland]

On Tue, Jan 10, 2017 at 06:50:19PM +0000, Jon Medhurst (Tixy) wrote:
> On Tue, 2017-01-10 at 18:34 +0000, Mark Rutland wrote:
> > Looking at the git log for arch/arm64/boot/dts/arm, most updates are
> > simply adding new descriptions, so a DTB from a year ago should work
> > just fine with mainline (modulo the Juno PCI window issue, which was a
> > DTB bug). Upgrading kernel shouldn't require a DTB upgrade to see
> > equivalent functionality.
> 
> But if you want the new functionality in the kernel, why should you be
> forced to wait for the bootloader to catch up (or do that work yourself)
> then upgrade to that new bootloader version? And what about the poor
> devs working on that new functionality, they're going to need to use not
> upstream device-trees. Then there's all the firmware and system
> configuration stuff that's in device-tree.

Developers working on low-level stuff will always need to be able to
override/upgrade/etc. I am certainly not arguing to remove those
capabilities.

The key point is that it is possible to provide a baseline DTB that is
good enough for most users, and will work with future kernels.

We're unlikely to get to a state where DTBs are perfect and complete
from day one. We can have something that remains usable.

Thanks,
Mark.