[Shared] Add support for arm64 (Apple M1).

Author: Daggolin

CMakeLists.txt

@@ -112,7 +112,9 @@ if(WIN32)
 	endif()
 else()
 	set(X86 OFF)
-	if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm")
+	if(CMAKE_SYSTEM_PROCESSOR MATCHES "^(arm64|aarch64)$")
+		set(Architecture "arm64")
+	elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm")
 		set(Architecture "arm")
 	elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^i.86$")
 		set(X86 ON)
@@ -388,4 +390,4 @@ endif()
 if(BuildTests)
 	enable_testing()
 	add_subdirectory("tests")
-endif()
+endif()

code/client/cl_cgame.cpp

@@ -64,7 +64,11 @@ qboolean CL_InitCGameVM( void *gameLibrary )
 	typedef void DllEntryProc( SyscallProc * );
 
 	DllEntryProc *dllEntry = (DllEntryProc *)Sys_LoadFunction( gameLibrary, "dllEntry" );
-	cgvm.entryPoint = (intptr_t (*)(int,...))Sys_LoadFunction( gameLibrary, "vmMain" );
+
+	// NOTE: arm64 mac has a different calling convention for fixed parameters vs. variadic parameters.
+	//       As the cgame entryPoints (vmMain) in jk2 and jka use fixed arg0 to arg7 we can't use "..." around here or we end up with undefined behavior.
+	//       See: https://developer.apple.com/documentation/apple-silicon/addressing-architectural-differences-in-your-macos-code
+	cgvm.entryPoint = (intptr_t (*)(int,intptr_t,intptr_t,intptr_t,intptr_t,intptr_t,intptr_t,intptr_t,intptr_t))Sys_LoadFunction( gameLibrary, "vmMain" );
 
 	if ( !cgvm.entryPoint || !dllEntry ) {
 #ifdef JK2_MODE

code/client/vmachine.cpp

@@ -34,7 +34,7 @@ VIRTUAL MACHINE
 */
 intptr_t	VM_Call( int callnum, ... )
 {
-	intptr_t args[10] = { 0 };
+	intptr_t args[8] = { 0 };
 	va_list ap;
 
 	if ( cgvm.entryPoint ) {
@@ -43,8 +43,7 @@ intptr_t	VM_Call( int callnum, ... )
 			args[i] = va_arg( ap, intptr_t );
 		va_end(ap);
 
-		return cgvm.entryPoint( callnum,  args[0],  args[1],  args[2], args[3], args[4],  args[5],  args[6], args[7],
-								args[8],  args[9]);
+		return cgvm.entryPoint( callnum,  args[0], args[1], args[2], args[3], args[4],  args[5],  args[6], args[7] );
 	}
 	return -1;
 }

code/client/vmachine.h

@@ -71,7 +71,10 @@ VIRTUAL MACHINE
 ==============================================================
 */
 typedef struct vm_s {
-	intptr_t	(*entryPoint)( int callNum, ... );
+	// NOTE: arm64 mac has a different calling convention for fixed parameters vs. variadic parameters.
+	//       As the cgame entryPoints (vmMain) in jk2 and jka use fixed arg0 to arg7 we can't use "..." around here or we end up with undefined behavior.
+	//       See: https://developer.apple.com/documentation/apple-silicon/addressing-architectural-differences-in-your-macos-code
+	intptr_t	(*entryPoint)( int callNum, intptr_t arg0, intptr_t arg1, intptr_t arg2, intptr_t arg3, intptr_t arg4, intptr_t arg5, intptr_t arg6, intptr_t arg7 );
 } vm_t;
 
 extern vm_t cgvm;

shared/qcommon/q_platform.h

@@ -108,6 +108,9 @@ along with this program; if not, see <http://www.gnu.org/licenses/>.
 		#define idx64
 		#define ARCH_STRING "x86_64"
 		#define Q3_LITTLE_ENDIAN
+	#elif defined(__arm64__)
+		#define ARCH_STRING "arm64"
+		#define Q3_LITTLE_ENDIAN
 	#endif
 
     #define DLL_EXT ".dylib"