[U-Boot] Boot X86 PC from USB using U_boot

Hi all please help me

Am a beginner in Linux. I have a PC with UBUNTU 9.04 installed . I was trying to boot Linux PC from USB. I could able to boot PC with GRUB installed in USB .

Is it possible to boot the PC (X86 architecture) from USB with U-Boot in the USB?

What all configuration changes I need do to make this possible?

I have downloaded U-boot then configured and build for X86 architecture (sc520_cdp_config) And made a bootable partition in usb and copied u-boot image in to it and tried to boot from usb but It is not working.

Please help me in this.................

With best regards, Anoop Sasi