I've had a look at the uboot for the igepv5 , and they set the ram timings in a slightly nicer way than just magical hex values. It's probably completely different ram, but maybe it's useful to compare how they set it up.
https://git.isee.biz/arm-boot/u-boot-arm/blob/u-boot-2014.01.y-omap5/board/i...
https://git.isee.biz/arm-boot/u-boot-arm/blob/u-boot-2014.01.y-omap5/board/i...