Design And Implementation Of DUET Loader Under Linux Environment

Unified Extensible Firmware Interface(UEFI)is the next generation standard of computer firmware raised by Intel. Mixed modern software engineering idea and design method, establish a flexible, robust, easily extensible, reusable, convenience firmware development framework for development & maintain. Based on the basis of UEFI framework, Intel provides a suit of UEFI Extensible Development Ki(tEDK, EDK2) and couples of UEFI emulation platform sample implementation according to open source forum. DUET platform included by EDK & EDK2, is an UEFI emulation platform different with which running over operation system level platforms, obvious feature is re-encapsulate the system calls and functions generated by legacy BIOS, to form UEFI Framework system interfaces for satisfy the requirement so as to run on real platform. To point against this feature, design and implementation of the emulation platform full reuse Library and Modules of EDK2 Core to simplify the code and workload in the whole hog.This thesis mainly focus on researching the functionality,design layout and implementation method. It discussed the differences and relationship of DUET platform with UEFI Framework and then Boot Sector based on MBR or GPT, the tool for write Boot Sector into specify sector in the boot media, and simply for write Shell script and Build Tools to compile the whole project.Thesis also described how to jump to DUET Loader after legacy BIOS finished to execute code in Boot Sector, switch into Protected Mode, decompress DXE image and prepare the Memory, Stack then passed to DXE Entrypoint as HOB required by DXE image for execute. Analyzed the memory layout of DUET Platform and the method of DxeIPL and EFI Loader's implementation, how to reuse the system calls of Legacy BIOS according to ACPI table.