if you're like me, getting toolchains known to work has always been problematic for the arches you don't care about. yes, there's the ELDK, but that doesn't cover all the arches that u-boot supports, and imo, they're "fatter" than necessary.
to that end, i've started posting toolchain builds here: http://dev.gentoo.org/~vapier/u-boot/ ~5MiB d/l is nice :)
when possible, i built them which means they're recent: binutils-2.21.1 and gcc-4.6.2. they were also built on an older glibc (2.4), so they should be usable on quite a lot of recent (and not so recent) systems. and i've statically linked in all the 3rd party libraries to avoid cross-distro issues (mpfr/gmp/mpc/etc...).
is there interest/possibility of posting these to denx ftp and then putting the URL into the wiki/README ? or perhaps the MAKEALL script when it can't find a usable toolchain ... -mike