RPi hangs in bootloader

[Tim Kientzle]

On Feb 18, 2013, at 5:05 PM, Ian Lepore wrote:
> On Mon, 2013-02-18 at 11:47 -0800, Tim Kientzle wrote:
>>> I do not understand the FDT_ERR_BADMAGIC, the page http://www.denx.de/wiki/DULG/UBootCmdFDT has a lot of those errors listed in an example session but does not explain what the message conveys?
>> 
>> To help me clarify my own understanding, I wrote a brief
>> explanation of where we are with FDT handling that
>> digs into how RPi boot handles FDT today and points
>> out some of the work that still remains.
>> 
> 
> While you're digging around in that area of the code... is there any way
> ubldr can find out from u-boot how it was loaded?  I would love it if
> ubldr could automatically set currdev=net0: if it was loaded via dhcp or
> tftp, and automatically use net0:/boot/loader.rc in that case as well.

I believe this is possible, but it would require some C-level
work on ubldr.  (And I'm not using netbooting in my current
dev environment, so I don't have a good way to test this
right now.)

The U-Boot API does provide a way to access the U-Boot
environment variables.   My work on ubldr right now is
using this to get the FDT information from U-Boot.

If I stumble across the specific hooks needed for this,
I'll let you know.

> The general thing I'm up to today is learning enough about ubldr to use
> it effectively, and ultimately to see if it can be used to load a
> (semi-)generic kernel plus a set of modules you configure in loader.rc.
> I've just managed to do that by hand, now to see if loader.rc will
> cooperate.

Modulo bugs, this should all work.  ubldr is just loader(8) with
U-Boot API grafted underneath instead of a PC BIOS.
So module loading and all the boot-time configuration
hooks that people are used to on x86 should Just Work.

A couple of folks have talked about turning on FICL
in ubldr, that would open even more automation
possibilities.

Tim