[Buildroot] How does the Start and Entry Point addresses for a uImage get set?

[Bob Bouterse]

Thanks for the beagleboard patch! I have morphed it into an omap3_evm
configuration. But I have hit a mystery...
When the uImage for my kernel is created with mkimage, the start address
is being set to 0x00008000, it should be 0x80008000 . The zreladdr-y in
linux/arch/arm/mach-omap2/Makefile.boot is set to 0x80008000 . 

Does anyone know how this gets set in the uImage header?

FYI, I found that the parameters to mkimage were set to zero in
buildroot/target/u-boot/Makefile.in . I modified these to 0x80000000,
and that corrected the problem, but I can't believe this is hard coded.