meta: replace cmake mono-build system with a custom build co-ordinator

every system component now has its own self-contained build system, and a
seed file describing the component and its build system and dependencies.

a new tool, meadow, collects and uses these seed files to build the
components into a full system. meadow also manages the target system root
and a host prefix where toolchain tools are installed to.

the build system has also been updated to use a new $ARCH-rosetta-gcc
compiler, and the patches files necessary to build it have been
added to toolchain/cross-compiler.

lib/libc/exec/CMakeLists.txt

@@ -1,5 +1,10 @@
 set(source_dirs unistd spawn)
 
+if (LIBC_STANDALONE)
+	cmake_minimum_required(VERSION 3.31)
+	project(libc-exec C ASM)
+endif ()
+
 file(GLOB sources *.c *.h)
 
 foreach (dir ${source_dirs})
@@ -13,21 +18,17 @@ endforeach (dir)
 file(GLOB_RECURSE sub_headers ${CMAKE_CURRENT_SOURCE_DIR}/include/*.h)
 set(headers ${headers} ${sub_headers})
 
-set(component_sources ${sources} PARENT_SCOPE)
-set(component_headers ${headers} PARENT_SCOPE)
-set(component_public_include_dirs ${CMAKE_CURRENT_SOURCE_DIR}/include PARENT_SCOPE)
-
-rosetta_add_library(STATIC
-	NAME libc-exec
-	PUBLIC_INCLUDE_DIRS
-		${public_include_dirs}
-		${CMAKE_CURRENT_SOURCE_DIR}/include
-	SOURCES ${sources}
-	HEADERS ${headers})
-
-sysroot_add_library(
-	NAME libc-exec
-	HEADER_DIR /usr/include
-	LIB_DIR /usr/lib)
+if (NOT LIBC_STANDALONE)
+	set(component_sources ${sources} PARENT_SCOPE)
+	set(component_headers ${headers} PARENT_SCOPE)
+	set(component_public_include_dirs ${CMAKE_CURRENT_SOURCE_DIR}/include PARENT_SCOPE)
+endif ()
 
+add_library(libc-exec STATIC ${sources} ${headers})
+target_include_directories(libc-exec PUBLIC
+	${public_include_dirs}
+	${CMAKE_CURRENT_SOURCE_DIR}/include)
 target_link_libraries(libc-exec libc-core libc-io libmagenta liblaunch-static)
+target_compile_definitions(libc-exec PRIVATE ENABLE_GLOBAL_HEAP=1 BUILD_STATIC=1)
+set_target_properties(libc-exec PROPERTIES PREFIX "")
+install(TARGETS libc-exec)

lib/libc/exec/libc-exec.seed

@@ -0,0 +1,18 @@
+[seed]
+name = 'libc-exec'
+
+[dependency]
+seeds = [
+	'libc-core',
+	'libc-io',
+	'libmagenta',
+	'liblaunch-static',
+]
+
+[build]
+build_system = 'cmake'
+configure_args = [
+	'-DLIBC_STANDALONE=TRUE'
+]
+
+# vim: ft=toml