efi-wrapper

Whats this?

A UEFI implemented running under OS (Linux), implemented some UEFI interfaces

NOTICE: the project is in the early experimental stage, and some functions may have many bugs and may not work as expected

This project is not a sandbox, efi program code will be executed directly!

How does it work?

As we all know, UEFI does not have system calls. Applications call UEFI services through System Table struct of arguments. As long as we implement System Table and then emulate some privileged instructions, we can run the UEFI program.

UEFI Shell

If you want to run UEFI Shell, you need HII related DXE (from EDK2):

HiiDatabase.efi
EnglishDxe.efi

Implemented UEFI protocols

gEfiDevicePathUtilitiesProtocolGuid
gEfiComponentNameProtocolGuid
gEfiComponentName2ProtocolGuid
gEfiGraphicsOutputProtocolGuid (SDL2 / VNC / MemoryOnly)
gEfiAbsolutePointerProtocolGuid (SDL2 / VNC)
gEfiSimplePointerProtocolGuid (SDL2 / VNC)
gEfiSimpleTextInProtocolGuid (SDL2 / VNC / STDIO)
gEfiSimpleTextInputExProtocolGuid (partial)
gEfiSimpleFileSystemProtocolGuid (write untested)
gEfiSimpleTextOutProtocolGuid
gEfiUnicodeCollationProtocolGuid
gEfiUnicodeCollation2ProtocolGuid

UEFI services (Boot Service / Runtime Service)

Unimplemented services

gRT->SetVirtualAddressMap (no possible)
gRT->ConvertPointer (no possible)
gRT->UpdateCapsule
gRT->QueryCapsuleCapabilities
gRT->SetTime (return EFI_ACCESS_DENIED)
gRT->GetWakeupTime
gRT->SetWakeupTime
gRT->GetNextHighMonotonicCount
gBS->GetNextMonotonicCount
gBS->UnloadImage
gBS->SetWatchdogTimer

Partial implemented services

gRT->ResetSystem (force exit application)
gRT->SetVariable (no persistent storage)
gRT->GetVariable (no persistent storage)
gRT->GetNextVariableName (no persistent storage)
gBS->ExitBootServices (fake exit)

Architecture:

x86_64 / amd64
aarch64 / arm-v8a
x86 / i386 (untested)
arm32 / arm-v7 (untested)

TODO

Fix STDIO Console
Implement SimpleTextInputEx
Implement HII Protocols
Emulate more privileged instructions

Bugs

All code are unstable
Memory management (pool allocate) are very bogous
Memory protection does not seem to be working properly, you may need add -p to arguments (enable memory permissive)
PE32 relocations broken
No persistent variable storage

Code used:

edk2
U-Boot

BigfootACA / efi-wrapper