I was hoping that a "default" or "vanilla" debian (incl kernel) would run on the device, but looks like it does not. I lso got the new Uboot in s I can now use the external-sd, and am experimenting with it. I first booted to the working micro-sd, and then mounted the external-sd and installed debootstrap on to it and later booted to th external-sd and completed the debian install. The debian installed fine, and also installed the vanilla debian kernel, but it hangs.... If I use the GST uImage, I can boot to this new debian-rootfs and that also works... no issues.
The issue of the GST software and in particular the kernel is a can of worms. Globalscale only support the software that they supply, taking the view that if you change your system and hit a problem, that's your responsibility and not theirs. I think that's a reasonable approach from their point of view; they can't hold your hand for every little problem when their customers decide to tinker. So you can live on the bleeding edge, discovering (and hopefully solving) lots of problems for yourself, or you can wait for others to report on those problems and solutions.
Since the kernel can be expected to have system-specific code (that's what arcNumber is all about), it can take a while for the appropriate changes to get promoted to mainline. If we are agreed that getting the right patch (so you can compile for yourself) or the right binary (because someone else already solved the problem), I can only repeat that the
plug computer forum is probably an essential stopping off place.
The script for downloading and applying a Dreamplug kernel is at
http://sheeva.with-linux.com/sheeva/README-DREAM-UPDATE.sh
