Migrating XO-1.75 to device tree - upgrade considerations

[Daniel Drake]

On Tue, Aug 21, 2012 at 4:06 PM, Jerry Vonau <jvonau at shaw.ca> wrote:
> While working with Australia, we have found the need to have the AC
> plugged-in for a firmware update while not requiring AC for a image
> upgrade to be problematic in the field. You can start an OS upgrade then
> run out of battery leaving a incomplete upgrade, while an AC adaptor may
> not always be available to use while your employing charging racks. We
> make our signed firmware available for download outside of the image, to
> enable the firmware to be installed from a USB drive before updating the
> OS. We disable the AC check and force a minimum 50% battery level before
> either actions can occur with our custom olpc.fth script which is part
> of our One Education USB[1] project. To my knowledge we have not bricked
> any XOs in the field using this method.

Is this driven because your OS update process is not resilient to power failure?

Either way, I don't quite understand the situation involving the
firmware here. (Maybe until now) there has been no driving need to
upgrade firmware when upgrading OS releases - it can be done before,
after, 3 weeks after, doesn't make a big difference. Or is there a
reason I'm missing for why you go to special lengths to make sure the
firmware upgrade is done first?

Thanks,
Daniel