Different uname machine type for x86_64.

* Added B_64_BIT_PC_PLATFORM platform type.
* Return "x86_64" as the machine type for that platform in uname.

headers/os/kernel/OS.h

@@ -713,7 +713,8 @@ typedef enum platform_types {
 	B_MK_61_PLATFORM,
 	B_NINTENDO_64_PLATFORM,
 	B_AMIGA_PLATFORM,
-	B_ATARI_PLATFORM
+	B_ATARI_PLATFORM,
+	B_64_BIT_PC_PLATFORM
 } platform_type;
 
 typedef struct {

src/system/kernel/arch/x86/arch_system_info.cpp

@@ -68,7 +68,11 @@ arch_get_system_info(system_info *info, size_t size)
 	// - various cpu_info
 	info->cpu_clock_speed = sCpuClockSpeed;
 	// - bus_clock_speed
+#ifdef __x86_64__
+	info->platform_type = B_64_BIT_PC_PLATFORM;
+#else
 	info->platform_type = B_AT_CLONE_PLATFORM;
+#endif
 
 	// ToDo: clock speeds could be retrieved via SMBIOS/DMI
 	return B_OK;

src/system/libroot/posix/sys/uname.c

@@ -55,6 +55,9 @@ uname(struct utsname *info)
 		case B_AT_CLONE_PLATFORM:
 			platform = "BePC";
 			break;
+		case B_64_BIT_PC_PLATFORM:
+			platform = "x86_64";
+			break;
 		default:
 			platform = "unknown";
 			break;