[U-Boot-Users] Problem about sdram initialization

Hi,I have a little problem with the u-boot startup.when it run to the function relocate_code(in the /cpu/ppc4xx/start.s),it don't run continually. Through LED on the board ,I find that it stops at the code below:

addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET mtlr r0 blr in_ram: My questions are why the u-boot stop here and where the code jump to?

thank you !