On Wednesday 28 January 2015 03:07:43 Nicolas Pitre wrote:
> In other words, what prevents someone from creating, say, a
> custom minimal Barebox version that sits on top of the
> existing N900 bootloader?  Wouldn't that provide a much
> better user experience?
> 

Strong cryptography used for signing first stage bootloader, 
undocumented interface and other stuff which initialize HW and 
small memory (about 100kB) for second stage non-signed 
bootloader. Next kernel image is limited to size 2MB. And 
currently uboot can be compiled to act as "kernel" image, so 
second stage bootloader can boot it.

I spend some time to replace second (non signed) bootloader with 
something other, but really it is not possible.

-- 
Pali Rohár
pali.rohar@gmail.com