The Basics UEFI boot officially has three phases (SEC, PEI and DXE).  However, the DXE phase is divided into DXEBoot and DXERuntime (the former is eliminated after the call to ExitBootSerivices()).  The jobs of each phase are SEC (SECurity phase). This contains all the CPU initialisation code from the cold boot entry point on.  It’s … Continue reading Anatomy of the UEFI Boot Sequence on the Intel Galileo