Difference between kernel load address and entry point

Load Address is RAM location where the kernel binary image is to be copied. Entry Point is the Location of the copied binary to be executed by uboot to boot kernel.

Your RAM is mapped at 80000000 and kernel LOAD ADDRESS is 80008000. bootm command uncompress the uImage from copied image location to 80008000 address and then calls the kernel entry point (may be the same address : 80008000) to execute the kernel.