I've successfully ported u-boot to the Sharp KEV7A400 board. It can program flash, boot from the network, and it runs from flash.
Before I submit a patch, I believe there are a couple of outstanding issues that you, Wolfgang, want resolved.
1) Dependency on Perl
Are you OK with an initial patch that checks for the presence of a Perl interpreter? Since this is the only board using the mkocnfigx script, such a method will be backward compatible. I agree that a shell script of the Perl script must be written.
2) #undef arm
It looks like the arm macro may be defined by the compiler. The GCC info pages suggest that this macro may be defined unless -ansi is passed to the compiler.
There are a few of ways to resolve this problem. I could change the structure that is broken by the #define. I could leave the #undef intact. I could find a way to remove the #define by passing an switch to the compiler. My preference, of course, is to leave the #undef intact.
3) Trailing whitespace
You found some lines in a previous patch to have trailing whitespace. What do you use to detect this?