Disk/network image (x86 BIOS)

In this case our full IPL isn't involved. An existing BIOS IPL loads the image into memory and transfers control to our IPL. Since the existing IPL doesn't know where in startup to jump, it always jumps to the start of the image. On the front of the image we build a tiny IPL that jumps to startup_vaddr:

Here's the step required in the IPL:

jump (startup_vaddr)