[Arm-netbook] motherboard negotiation

[jonsmirl at gmail.com]

On Fri, Jan 13, 2012 at 11:09 AM, lkcl luke <luke.leighton at gmail.com> wrote:
> ok, separate discussion
>
> i'd taken into consideration being able to identify motherboards, by
> putting in an I2C EEPROM.  various ideas included having a USB-like
> "category / class" thing, and also the idea of putting the linux
> kernel device tree data directly into the I2C EEPROM had occurred to
> me.

A scheme based on device tree is probably the best bet. uboot already
takes the built-in device tree and adjusts it for the amount RAM,
flash, CPU clk speed.

The base board will need to have some device tree nodes described in
the EEPROM. The uboot on the EOMA card will read these and then look
for markers in it's tree on where to insert these nodes. This is
similar to how clock speed is fixed up.

You need to use substitution markers since EOMA board 1 might have
i2c-1 connected to the PCMCIA connector and board 2 might have i2c-3
brought out to the connector. Or it might not have anything connected.

You can't put the full device tree into the baseboard since you are
planning on changing CPUs in the future.

Uboot has no current support for any of this.


>
> other than that: the exact implementation details are up-for-grabs.
>
> thoughts anyone?
>
> l.
>
> p.s. yes there's fun and games involved in suspend, remove-card,
> insert-card, resume....
>
> _______________________________________________
> arm-netbook mailing list arm-netbook at lists.phcomp.co.uk
> http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
> Send large attachments to arm-netbook at files.phcomp.co.uk



-- 
Jon Smirl
jonsmirl at gmail.com