From 80b6c1a4f39961deffde903e5b8eb9434f7e3706 Mon Sep 17 00:00:00 2001
From: Duncan Ogilvie <mr.exodia.tpodt@gmail.com>
Date: Mon, 11 Nov 2024 23:37:12 +0100
Subject: [PATCH] Add basic UEFI support

---
 cmake/Platform/UEFI.cmake        | 13 +++++++++++++
 cmake/zig-toolchain-uefi64.cmake |  2 ++
 cmake/zig-toolchain.cmake        |  7 +++++++
 3 files changed, 22 insertions(+)
 create mode 100644 cmake/Platform/UEFI.cmake
 create mode 100644 cmake/zig-toolchain-uefi64.cmake

diff --git a/cmake/Platform/UEFI.cmake b/cmake/Platform/UEFI.cmake
new file mode 100644
index 0000000..c1359bd
--- /dev/null
+++ b/cmake/Platform/UEFI.cmake
@@ -0,0 +1,13 @@
+# References:
+# - https://gitlab.kitware.com/cmake/cmake/-/merge_requests/6630
+# - https://gitlab.kitware.com/cmake/cmake/-/issues/16538
+# - https://kubasejdak.com/how-to-cross-compile-for-embedded-with-cmake-like-a-champ
+
+include(Platform/Generic)
+
+set(CMAKE_EXECUTABLE_SUFFIX ".efi")
+set(CMAKE_SHARED_LIBRARY_SUFFIX ".efi")
+set(CMAKE_SHARED_LIBRARY_PREFIX "")
+
+# UEFI APIs might expect 16-bit wchar_t
+add_compile_options(-fshort-wchar)
diff --git a/cmake/zig-toolchain-uefi64.cmake b/cmake/zig-toolchain-uefi64.cmake
new file mode 100644
index 0000000..a60a3e1
--- /dev/null
+++ b/cmake/zig-toolchain-uefi64.cmake
@@ -0,0 +1,2 @@
+set(ZIG_TARGET "x86_64-uefi-gnu")
+include(${CMAKE_CURRENT_LIST_DIR}/zig-toolchain.cmake)
diff --git a/cmake/zig-toolchain.cmake b/cmake/zig-toolchain.cmake
index 1304ae1..c7ad918 100644
--- a/cmake/zig-toolchain.cmake
+++ b/cmake/zig-toolchain.cmake
@@ -20,6 +20,10 @@ elseif(ZIG_OS STREQUAL "macos")
     set(CMAKE_SYSTEM_NAME "Darwin")
 elseif(ZIG_OS STREQUAL "freestanding")
     set(CMAKE_SYSTEM_NAME "Generic")
+elseif(ZIG_OS STREQUAL "uefi")
+    set(CMAKE_SYSTEM_NAME "UEFI")
+    # Fix compiler detection (lld-link: error: <root>: undefined symbol: EfiMain)
+    set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
 else()
     # NOTE: If this happens, add a new case with one of the following system names:
     # https://cmake.org/cmake/help/latest/variable/CMAKE_SYSTEM_NAME.html#system-names-known-to-cmake
@@ -42,3 +46,6 @@ endif()
 set(CMAKE_AR "${CMAKE_CURRENT_LIST_DIR}/zig-ar${SCRIPT_SUFFIX}")
 set(CMAKE_RANLIB "${CMAKE_CURRENT_LIST_DIR}/zig-ranlib${SCRIPT_SUFFIX}")
 set(CMAKE_RC_COMPILER "${CMAKE_CURRENT_LIST_DIR}/zig-rc${SCRIPT_SUFFIX}")
+
+# Add custom UEFI platform to module path
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")