EFI_DXE-Emulator: EFI DXE Emulator and Interactive Debugger!

Pedro Vilaca has created EFI DXE Emulator. It is an EFI DXE phase binaries emulator based on Unicorn. It allows to run EFI DXE binaries inside a Unicorn virtual nachine with a basic interactive debugger that allows to step and interact with the EFI code. It works by implementing basic EFI Boot and Runtime services. Not every service is yet implemented, such as services to load and locate other binaries. This can be done with extra work, since the core code to load binaries already exists, although it needs to be modularized. Can be used to easier reverse some EFI binaries that don’t interact with hardware or graphical EFI interface. The debugger is still pretty basic but allows to view and modify registers and memory, step into calls or over them, and breakpoints. […] Even with all its limitations this is a pretty useful tool for reversing some EFI binaries, improving a lot the reverse engineering process from a static analysis only (for us who don’t have 6k JTAG based EFI debuggers). It’s also a nice showcase of Unicorn potential and limitations. With further development it could be expanded to fuzzing and vulnerability discovery in firmware world.[…]

https://reverse.put.as/2019/10/29/crafting-an-efi-emulator/

https://github.com/gdbinit/efi_dxe_emulator

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