The register to physically access 4GByte DDR3 RAM is set to:
Memory above 2GByte is physically available and we can read/write using U-boot md/mw commands.
When CONFIG_DDR_MB is set to 2048, U-boot is fine.
But when we make CONFIG_DDR_MB above 2048 (more than 2GByte) and it does not work, U-boot freezes when it tries to relocate itself.
What else needs to be changed?