[U-Boot] U-Boot bootup process

Hello there,

I'm very new to U-Boot. I'm programming an AMCC PPC440EP (Yosemite) board that will run LynxOS.

Would anyone help me with U-Boot bootup process? On power up, where U-Boot starts executing from and what's the flow of it? What functions it calls? I need to understand the whole picture, like what gets initialized when!

Any kind of information/block-diagram would greatly be appreciated.

Thanks,

Muzammal