Cmake build generator support: build stage

Multi-target architecture implementation:
    each root source code directory presents the one
    *INTERFACE* target to it's subdirectory subtargets
    that link only as *STATIC* library.
    For instance, *arch* directory presents *Architecture* target
    then *Architecture* target has *CPUID*, *IO*, *PORT*
    and etc. dependencies

Exact order of linking targets is: boot.o CRTIBUNDLE <TARGETS> CRTNBUNDLE.
Sequence destruction cause to UB. Please to pay attention to this.

TODO
- Debug information
- Build type
- Toolchain file
- Image creation
- Build by WinGW compiler on Windows platform (optional)

Signed-off-by: Alexey Gavrilov <alexey.gavrilov@mail.com>

1 files changed, 99 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..33ac2dc
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,99 @@
+# Regard that file as root of whole project
+# which include farther subprojects source codes
+
+# Expected input variables:
+#   ARCH: type of architecture 
+
+set(CXX_FLAGS
+    -Wall
+    -ffreestanding
+    -nostdinc
+    -nostdlib
+    -fno-rtti
+    -mgeneral-regs-only
+)
+
+#---DEV PROPERTIES--- (delete in production)
+# message(STATUS ${CMAKE_ASM_NASM_COMPILER})
+set(CMAKE_SYSTEM_NAME Generic)
+set(CMAKE_ASM_NASM_OBJECT_FORMAT elf32)
+set(CMAKE_CXX_COMPILER i686-elf-g++)
+set(CMAKE_CXX_COMPILER_WORKS 1)
+# set(CMAKE_CUSTOM_LINKER i686-elf-ld)
+# set(CMAKE_CXX_LINK_EXECUTABLE
+#     "ld <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
+# set(CMAKE_CXX_FLAGS "-I${CMAKE_CURRENT_LIST_DIR}/include")
+# set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32 -Wall -ffreestanding -nostdinc -nostdlib -fno-rtti -mgeneral-regs-only")
+# message(STATUS ${CMAKE_ASM_NASM_FLAGS})
+# message(STATUS ${CMAKE_ASM_NASM_OBJECT_FORMAT})
+# message(STATUS ${CMAKE_CXX_LINK_EXECUTABLE})
+# message(STATUS ${CMAKE_CXX_LINK_FLAGS})
+#--------------------------------------------
+
+cmake_minimum_required(VERSION 3.25)
+
+project(ObjectiveProject LANGUAGES CXX ASM_NASM)
+
+list(APPEND CMAKE_MODULE_PATH
+    "${ObjectiveProject_SOURCE_DIR}/cmake/module"
+)
+
+include(metadata)
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+add_executable(Objective)
+
+# Set architecture by default if not present
+if(NOT ARCH IN_LIST OBJECTIVE_SUPPORTED_PROCESSORS)
+    list(GET OBJECTIVE_SUPPORTED_PROCESSORS 0 ARCH)
+endif()
+
+# Create target with compiler requirements (include directories, flags and etc)
+add_library(CXX_COMPILER_REQUIREMENTS INTERFACE)
+
+# Target with linker requirements
+add_library(CXX_LINKER_REQUIREMENTS INTERFACE)
+target_link_options(CXX_LINKER_REQUIREMENTS INTERFACE
+    ${CXX_FLAGS}
+)
+target_link_libraries(CXX_LINKER_REQUIREMENTS INTERFACE
+    gcc
+)
+
+# Set compiler flags
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang|GNU")
+    target_compile_options(CXX_COMPILER_REQUIREMENTS INTERFACE
+        ${CXX_FLAGS}
+    )
+endif()
+
+target_include_directories(CXX_COMPILER_REQUIREMENTS
+    INTERFACE
+        ${ObjectiveProject_SOURCE_DIR}/include
+)
+
+# Subscribe compiler requirements to Object executable
+target_link_libraries(Objective PUBLIC CXX_COMPILER_REQUIREMENTS)
+
+add_subdirectory(arch)
+add_subdirectory(kernel)
+add_subdirectory(drivers)
+add_subdirectory(include)
+add_subdirectory(libgcc)
+
+target_sources(Objective PRIVATE
+    $<TARGET_OBJECTS:Boot>
+)
+
+target_link_libraries(Objective PRIVATE
+    CRTI
+    Architecture
+    Kernel
+    Drivers
+    CRTN
+)
+
+target_link_libraries(Objective PRIVATE CXX_LINKER_REQUIREMENTS)