[U-Boot] Keyboard enable at u-boot for Beagleboard

Hi , I have an issue regarding u-boot. I'm using Beagle-board Rev B as well as omap3_evm. i would like to enable keyboard at the u-boot level,i.e the keyboard is connected to the target and entering the text.But the problem is that at the U-boot, keyboard is not responding( no lights ) for both the devices.When i checked the USB info ,the current for keyboard was 70mA(actual 100mA for keyboard). But after the boot level the keyboard light blinks and works well and fine. What will be the reason for lowering the current at the u-boot and increasing after the initialization of the USB at the kernel level?? Is there any change i have to make in the U-boot code for beagle board as well as for the omap3_evm??