[U-Boot] [PATCH v2 04/11] fdt: Add device tree memory bindings

[Tom Rini]

On Fri, Oct 24, 2014 at 02:04:00PM -0600, Simon Glass wrote:
> Hi Tom,
> 
> On 24 October 2014 12:49, Tom Rini <trini at ti.com> wrote:
> > On Thu, Oct 23, 2014 at 06:58:50PM -0600, Simon Glass wrote:
> >
> >> From: Michael Pratt <mpratt at chromium.org>
> >>
> >> Support a default memory bank, specified in reg, as well as
> >> board-specific memory banks in subtree board-id nodes.
> >>
> >> This allows memory information to be provided in the device tree,
> >> rather than hard-coded in, which will make it simpler to handle
> >> similar devices with different memory banks, as the board-id values
> >> or masks can be used to match devices.
> > [snip]
> >> +++ b/doc/device-tree-bindings/memory/memory.txt
> >> @@ -0,0 +1,67 @@
> >> +* Memory binding
> >> +
> >> +The memory binding for U-Boot is as in the ePAPR with the following additions:
> >
> > I am wary of being different from ePAPR / Linux Kernel.  What do we need
> > this for / when do we use it?
> 
> This extends the existing binding. It allows the location and size of
> memory to be set by a board ID. Unfortunately on sopme hardware you
> get a hang if you try to access memory that doesn't exist, so this
> allows the range of available memory to be defined - or at least the
> maximum bound since we still probe the memory size within that range.
> 
> This feature is used on several Exynos Chromebooks.

So that you can use the same DT on several disjoint boards?  How does
this work with the kernel, does U-Boot then pass along only the correct
map?  Patches to the kernel to also deal with this?

-- 
Tom
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