Last updated: March 4th, 2024.

This fork of the Unicorn Engine brings support for building Unicorn-based applications and drivers in the UEFI firmware environment. This was developed as part of MultiArchUefiPkg.

This repo is intended to be temporary, as part of upstreaming activities. Our intention is to merge the UEFI support and assorted fixes into the main project repository.

See README.md for the original Unicorn Engine README.

Currently the supported targets are AARCH64 UEFI and RISCV64 UEFI.

You need the TianoCore UEFI EDK2 environment set up. Here's an example for how the some of the Unicorn sample apps could be built in an EDK2 environment targeting RISCV64:

. edksetup.sh
export GCC5_RISCV64_PREFIX=riscv64-linux-gnu-

build -a RISCV64 -t GCC5 -p unicorn/efi/UnicornPkg.dsc -b DEBUG

You get UnicornSampleX86, UnicornSampleArm64 and UnicornSampleRV. The latter shows how it's possible to link against multiple target emulation libraries.

MultiArchUefiPkg itself is a great example of how to use Unicorn with UEFI.

Here's a rough idea of what's supposed to work. File bugs if UnicornPkg doesn't build for you.

• gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.1)

• gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04)
• gcc version 11.3.0 (Ubuntu 11.3.0-1ubuntu1~22.04.1)
• gcc version 12.2.0 (g2ee5e430018, from https://github.com/riscv-collab/riscv-gnu-toolchain)

• gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
• gcc version 13.1.0 (Homebrew GCC 13.1.0)

You're using a smaller machine and LTO is consuming all memory. Modify the UC_LTO_JOBS build parameter in UnicornPkg.dsc If the value is too high, the build may abort. If the value is too low, the build may take forever.

Modify the UC_LTO_JOBS build parameter in UnicornPkg.dsc to a higher value or 'auto'. If the value is too high, the build may abort. If the value is too low, the build may take forever.

Note: newer versions of GCC (e.g. GCC 13) do much better with LTO compared to GCC 9, both in terms of speed and resource use.