[Re-adding the most obvious People to Cc]
On 30.01.2015 13:44, David Goodenough wrote:
On Friday 30 January 2015 13:03:59 Sebastian Hesselbarth wrote:
On 30.01.2015 12:41, Jean-Francois Moine wrote:
On Fri, 30 Jan 2015 12:00:16 +0100
Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx> wrote:
That what dtsi's are made for with one exception: the dtsi cannot "run"
on its own but needs at least one baseboard.dts that includes it. We
could create a "bare"-baseboard that represents what is (easily)
accessible on the SoM itself. Given the fact that even UART0 needs a
baseboard that grabs it from the SoM connector, I see no value in that.
In any case, any real cm-a510 board should work with the
generic/full .dts even if some hardware modules are lacking. No?
Nope. The cm-a510 is just an add-on for a baseboard, it does not make
a working board. Just think of it as a feature-improved SoC.
This sounds like capes on the BeagleBoard. Are these extension boards
self-identifying? If so then the approach used with the capes might work
here too.
David,
IMHO capes are a different thing. The BB can run just fine without any
cape installed, the cm-a510 cannot run without a baseboard. Also, once
you have your SoM installed it cannot change over runtime, there is no
need for any dynamic overlays and such.
You can build some 5 or 10 different configurations given the SoM and
a specific baseboard but not hundreds of possible combinations.
Besides, Gabriel is the first in almost 2 years that actually has an
cm-a510 - so, I doubt we'll have to mainline dozens of baseboards
using the cm-a510 in the near future.
Regarding the self-identification, it would be great if the actual SoM
configuration would be stored in the (always available) SPI flash, but
from my experience with the boards I have seen so far, I have a bad
feeling about it ;) A quick look at the sb-a510 (the compulab baseboard
for cm-a510) suggests that there is more configuration available but
by jumpers that (hopefully) can be read out by GPIOs at least.
The best similar board available in mainline I can remember is the
SolidRun Hummingboard, i.e. one baseboard that can be equipped with
3-4 different SoMs.
Sebastian
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