the sequence of init beagle board sdram in uboot

As my known, the sequence of init sdram of omap3530 is that:
uboot start.S calling lowe_level_init, then the s_init C function will
do the job.

When I boot into my board, the print_cpu_info function doesn't show
any DRAM size inforamtion, only show LPDDR and board version

I checked the uboot code, got the information : memory size
information supplied by board configuration C header file located in

So, I don't know why? and, could anybody tell how to debug uboot?

In the design principle of Uboot:

it is explicitly mentioned that debugging can be done via jtag or BDM:

Trying learning OpenOCD. A cheap JTAG debugger is Bus Pirate:

which runs well with OpenOCD.

For a good tutorial on OpenOCD: