We have been using the 1GB QWKS board for our development and and have followed the "Yocto Linux Patch Release Notes and User's Guide" without any problems.
We based our design on the QWKS based on the MSCMMX6QZDK08AB but the customer wanted to use the 2GB MSCMMX6QZDK08AB2G0AA. The old version of u-boot loads without error using the imx_usb tool but u-boot does not start. I suspect the DDR settings in one of the u-boot .cfg files.
Can anyone point me to a version of u-boot that works with the MSCMMX6QZDK08AB2G0AA ???