Even though the Raspberry Pi can directly boot a kernel, we'd still like to boot via U-Boot. Thus let's grab the latest version of mainline U-Boot, configure it for our Raspberry Pi and build a u-boot.

Does Raspbian use U-Boot?

The Raspberry Pi actually has native support for booting a kernel, you don't have to use U-Boot. However, one of the neat things about U-Boot is that it can provide netboot capabilities, so that you can boot your device from images across the network (we're just going to use it to boot a kernel and initramfs, however).

What is the default boot for Raspberry Pi?

You can choose between three boot options: Console Text console, requiring login (default) – boots into the command line. The default option. Desktop Log in as user 'pi' at the graphical desktop – boots into a graphical desktop environment.