I've noticed that the built version of u-boot in git is

122372 Jul 16 13:56 build/u-boot.bin

the version in the updater is

165060 Aug 12 23:38 ubootsb.bin

the version in flash is about 148KiB based on dumping flash.

I suppose the real question is this, how do we build the release version of u-boot?

The git version of u-boot appears to halt with an exception. I built with the efikamx configuration using the latest arm cross compiler from CodeSourcery.

arm-2011.03-42-arm-none-eabi-i686-pc-linux-gnu

It halts with an abort exception. After some debugging it looks like this is a data abort and the cause is that the UART register block is not mapped to its physical address even though the driver is using physical addresses. In this case, 0x73fbc000.

It's also clear that the release version is different from the one in Git from start. The dcd header uses some different values in the Git version from the released build.

Looks like I was close but not quite accurate. The trouble doesn't seem to be an MMU mapping. It's much simpler. The UART enable bit isn't set so the SoC is aborting on any IO to the UART RX or TX registers.