# Copyright (c) 2026 Dominic Masters
#
# This software is released under the MIT License.
# https://opensource.org/licenses/MIT
#
# CMake toolchain file for Sega Saturn (Hitachi SH-2, big-endian)
# using the Yaul homebrew SDK.  Set YAUL_INSTALL_ROOT or the
# YAUL_INSTALL_ROOT environment variable before invoking cmake.

set(CMAKE_SYSTEM_NAME Generic)
set(CMAKE_SYSTEM_PROCESSOR sh2)

# Resolve Yaul install root
if(NOT DEFINED YAUL_INSTALL_ROOT)
  if(DEFINED ENV{YAUL_INSTALL_ROOT})
    set(YAUL_INSTALL_ROOT "$ENV{YAUL_INSTALL_ROOT}"
        CACHE PATH "Yaul SDK root" FORCE)
  else()
    set(YAUL_INSTALL_ROOT "/opt/yaul"
        CACHE PATH "Yaul SDK root" FORCE)
  endif()
endif()

# Yaul SH-2 cross-compiler prefix is sh2eb-elf (big-endian SH-2 ELF).
# Binaries live in ${YAUL_INSTALL_ROOT}/bin/; headers/libs under
# ${YAUL_INSTALL_ROOT}/sh2eb-elf/{include,lib}/.
set(_YAUL_BIN "${YAUL_INSTALL_ROOT}/bin")

set(CMAKE_C_COMPILER   "${_YAUL_BIN}/sh2eb-elf-gcc")
set(CMAKE_CXX_COMPILER "${_YAUL_BIN}/sh2eb-elf-g++")
set(CMAKE_AR           "${_YAUL_BIN}/sh2eb-elf-ar")
set(CMAKE_RANLIB       "${_YAUL_BIN}/sh2eb-elf-ranlib")
set(CMAKE_STRIP        "${_YAUL_BIN}/sh2eb-elf-strip")
set(CMAKE_OBJCOPY      "${_YAUL_BIN}/sh2eb-elf-objcopy")
set(CMAKE_LINKER       "${_YAUL_BIN}/sh2eb-elf-ld")

set(CMAKE_CROSSCOMPILING TRUE)

# Tell CMake not to try to run built executables
set(CMAKE_CROSSCOMPILING_EMULATOR "" CACHE STRING "" FORCE)
set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)

# Sysroot — Yaul installs headers/libs under the arch-prefix subdirectory
set(_YAUL_SYSROOT "${YAUL_INSTALL_ROOT}/sh2eb-elf")
set(CMAKE_FIND_ROOT_PATH "${_YAUL_SYSROOT}")
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

# SH-2 core flags: big-endian (-mb), SH-2 ISA (-m2), no FPU
set(_SAT_C_FLAGS "-m2 -mb -fno-builtin -fomit-frame-pointer")
set(CMAKE_C_FLAGS_INIT   "${_SAT_C_FLAGS}")

# Yaul installs yaul.specs to ${YAUL_INSTALL_ROOT}/sh2eb-elf/lib/ and
# ldscripts/yaul.x to ${YAUL_INSTALL_ROOT}/sh2eb-elf/lib/ldscripts/.
# GCC searches ${prefix}/${target}/lib/ for specs, so -specs=yaul.specs works
# without an absolute path once the SDK is installed.
set(CMAKE_EXE_LINKER_FLAGS_INIT
  "-specs=yaul.specs -Wl,--gc-sections -nostartfiles -Wl,--start-group -Wl,--end-group")