[U-Boot] How to enable debug information in u-boot

Hello all, Is there any ways to activate more debugging information during SPL and u-boot process? I´m trying to boot u-boot for the Hackberry using Henrik source code but im only getting the following via serial console: U-Boot SPL 2012.10-04714-gc9a957f-dirty (Oct 31 2012 - 20:30:47)Board: sunxi

Regards,Paulo