Minimalist UEFI in Userspace

This toolset allows one to quickly port UEFI code to userspace utilities in popular operating systems such as macOS, Windows, or Linux. The only requirement is a C11-supporting compiler with the build scripts adopted for modern versions of clang and gcc.

Quick start

Create a Makefile with the contents similar to an example below:

PROJECT = ProjectName
PRODUCT = $(PROJECT)$(SUFFIX)
OBJS    = $(PROJECT).o ExtraObject.o

VPATH   = ../../Library/MyExtraLib:$

include ../../User/Makefile
CFLAGS += -I../../Library/MyExtraLib

Build it with the make command.

Flags and arguments

Additional variables are supported to adjust the compilation process.

• COVERAGE=1 — build with coverage information gathering.
• DEBUG=1 — build with debugging information.
• FUZZ=1 — build with fuzzing enabled.
• FUZZ_JOBS=2 — run with 2 fuzzing jobs (defaults to 4).
• FUZZ_MEM=1024 - run with 1024 MB fuzzing memory limit (defaults to 4096).
• SANITIZE=1 — build with LLVM sanitizers enabled.
• CC=cc — build with cc compiler (e.g. i686-w64-mingw32-gcc for Windows).
• DIST=Target — build for target Target (e.g. Darwin, Linux, Windows).
• STRIP=strip — build with strip stripping tool (e.g. i686-w64-mingw32-strip for Windows).
• OC_PATH - path to OpenCorePkg for out-of-tree utilities (defaults to ../..).
• UDK_ARCH=Ia32 — build with 32-bit UDK architecture (defaults to X64).
• UDK_PATH=/path/to/UDK — build with custom UDK path (defaults to $PACKAGES_PATH).
• WERROR=1 — treat compiler warnings as errors.

Example 1. To build for 32-bit Windows (requires MinGW installed) use the following command:

UDK_ARCH=Ia32 CC=i686-w64-mingw32-gcc STRIP=i686-w64-mingw32-strip DIST=Windows make

Example 2. To build with LLVM sanitizers use the following command:

DEBUG=1 SANITIZE=1 make

Example 3. Perform fuzzing and generate coverage report:

# MacPorts clang is used since Xcode clang has no fuzzing support.
CC=clang-mp-10 FUZZ=1 SANITIZE=1 DEBUG=1 make fuzz
# LCOV is required for running this command.
make clean
COVERAGE=1 DEBUG=1 make coverage

Predefined variables

Most UDK variables are available due to including the original headers.

• To distinguish target platform MDE_CPU_* variables can be used. For example, MDE_CPU_IA32 for 32-bit Intel and MDE_CPU_X64 for 64-bit Intel.
• To distinguish from normal UEFI compilation use EFIUSER variable.
• To detect debug build use EFIUSER_DEBUG variable.
• To detect sanitizing status use SANITIZE_TEST.
• To detect fuzzing status use FUZZING_TEST.
• Use ENTRY_POINT variable for main to automatically disable it for fuzzing.