In my latest u-boot builds I had some strange behaviour that I finally tracked down to not fixed up flash addresses in relocated u-boot. These addresses come from symbols in the .data.rel.ro.local section that is not handled by u-boot linker scripts at the moment.
Some background on relro: http://www.airs.com/blog/archives/189
Joerg Albert already inquired about this on the gcc ML: https://gcc.gnu.org/ml/gcc-help/2014-02/msg00017.html and he already suggested a solution: https://gcc.gnu.org/ml/gcc-help/2014-02/msg00054.html
So there a three things to notice: 1. Do not use gcc 4.8 and u-boot at the moment. 2. You might not notice that you have a problem until you erase u-boot from flash (and get your cache flushed). 3. Handling relro properly should be on the TODO-List
Maybe this is already common knowledge an maybe somebody is already working on this - but I did not notice yet. So in this case: sorry for the noise :)
Cheers Dirk