Re: Device tree bindings for linux ramoops use

On Thu, Jan 05, 2012 at 08:39:50PM -0800, Olof Johansson wrote:

Hi,

I'm considering how to best describe the data that ramoops needs in
the device tree.

The idea is really about describing a memory area that is (likely to
be) nonvolatile across reboots. Said area is not to be included in the
regular memory map of the system (i.e. not covered by /memory).

I have a few options on where to do it. It's not really a hardware
device per se, so it's a gray area for the device tree alltogether.

How about something like?

compatible = "linux,ramoops"
linux,ramoops-start = <start address of preserved ram>
linux,ramoops-size = ...

I'm not a fan of using separate start & size properties.  I'd rather
see a 'reg' type property like "linux,ramoops-mem = <start size>;",
but doing it in separate properties does may early boot code easier to
write.  I assume that is why the initrd start and size values are
passed separately.

I can probably be convinced either way though.

g.