While a single kernel for arm32 is technically possible
it would be a large amount of work.  With only a single
entry point, we would want to be able to sniff what
platform booted us and set up various platform-specific
things up.  The sniff would be hard and would require
changes to bootloaders some of which we can't change.

Also, there is the problem that many of the arm32 platforms
don't have the option of having a lot of RAM.  A single
GENERIC would waste a considerable of RAM for those
buses & drivers that could never be used.

Look at the hoops i386 has to do to support lowend i386
and high-end i386 machines.
--
Matt Thomas               Internet:   matt@3am-software.com
3am Software Foundry      WWW URL:    http://www.3am-software.com/bio/matt/
Cupertino, CA             Disclaimer: I avow all knowledge of this message