diff --git a/headers/private/kernel/syscalls.h b/headers/private/kernel/syscalls.h
index 0a27da785c..72783d70e8 100644
--- a/headers/private/kernel/syscalls.h
+++ b/headers/private/kernel/syscalls.h
@@ -260,156 +260,127 @@ extern status_t		_kern_get_cpuid(cpuid_info *info, uint32 eax, uint32 cpu);
 #endif
 
 
-/* DDM syscalls */
+/* Disk Device Manager syscalls */
 
 // iterating, retrieving device/partition data
-partition_id _kern_get_next_disk_device_id(int32 *cookie, size_t *neededSize);
-partition_id _kern_find_disk_device(const char *filename, size_t *neededSize);
-partition_id _kern_find_partition(const char *filename, size_t *neededSize);
-status_t _kern_get_disk_device_data(partition_id deviceID, bool deviceOnly,
-									bool shadow, user_disk_device_data *buffer,
-									size_t bufferSize, size_t *neededSize);
-
-partition_id _kern_register_file_device(const char *filename);
-status_t _kern_unregister_file_device(partition_id deviceID,
-									  const char *filename);
+extern partition_id	_kern_get_next_disk_device_id(int32 *cookie, size_t *neededSize);
+extern partition_id	_kern_find_disk_device(const char *filename, size_t *neededSize);
+extern partition_id	_kern_find_partition(const char *filename, size_t *neededSize);
+extern status_t		_kern_get_disk_device_data(partition_id deviceID, bool deviceOnly,
+						bool shadow, user_disk_device_data *buffer,
+						size_t bufferSize, size_t *neededSize);
+extern partition_id	_kern_register_file_device(const char *filename);
+extern status_t		_kern_unregister_file_device(partition_id deviceID,
+						const char *filename);
 	// Only a valid deviceID or filename need to be passed. The other one
 	// is -1/NULL. If both is given only filename is ignored.
 
 // disk systems
-status_t _kern_get_disk_system_info(disk_system_id id,
-									user_disk_system_info *info);
-status_t _kern_get_next_disk_system_info(int32 *cookie,
-										 user_disk_system_info *info);
-status_t _kern_find_disk_system(const char *name, user_disk_system_info *info);
+extern status_t		_kern_get_disk_system_info(disk_system_id id,
+						user_disk_system_info *info);
+extern status_t		_kern_get_next_disk_system_info(int32 *cookie,
+						user_disk_system_info *info);
+extern status_t		_kern_find_disk_system(const char *name, user_disk_system_info *info);
+extern bool			_kern_supports_defragmenting_partition(partition_id partitionID,
+						int32 changeCounter, bool *whileMounted);
+extern bool			_kern_supports_repairing_partition(partition_id partitionID,
+						int32 changeCounter, bool checkOnly, bool *whileMounted);
+extern bool			_kern_supports_resizing_partition(partition_id partitionID,
+						int32 changeCounter, bool *canResizeContents, bool *whileMounted);
+extern bool			_kern_supports_moving_partition(partition_id partitionID,
+						int32 changeCounter, partition_id *unmovable,
+						partition_id *needUnmounting, size_t bufferSize);
+extern bool			_kern_supports_setting_partition_name(partition_id partitionID,
+						int32 changeCounter);
+extern bool			_kern_supports_setting_partition_content_name(partition_id partitionID,
+						int32 changeCounter, bool *whileMounted);
+extern bool			_kern_supports_setting_partition_type(partition_id partitionID,
+						int32 changeCounter);
+extern bool			_kern_supports_setting_partition_parameters(partition_id partitionID,
+						int32 changeCounter);
+extern bool			_kern_supports_setting_partition_content_parameters(
+						partition_id partitionID, int32 changeCounter, bool *whileMounted);
+extern bool			_kern_supports_initializing_partition(partition_id partitionID,
+						int32 changeCounter, const char *diskSystemName);
+extern bool			_kern_supports_creating_child_partition(partition_id partitionID,
+						int32 changeCounter);
+extern bool			_kern_supports_deleting_child_partition(partition_id partitionID,
+						int32 changeCounter);
+extern bool			_kern_is_sub_disk_system_for(disk_system_id diskSystemID,
+						partition_id partitionID, int32 changeCounter);
 
-bool _kern_supports_defragmenting_partition(partition_id partitionID,
-											int32 changeCounter,
-											bool *whileMounted);
-bool _kern_supports_repairing_partition(partition_id partitionID,
-										int32 changeCounter, bool checkOnly,
-										bool *whileMounted);
-bool _kern_supports_resizing_partition(partition_id partitionID,
-									   int32 changeCounter,
-									   bool *canResizeContents,
-									   bool *whileMounted);
-bool _kern_supports_moving_partition(partition_id partitionID,
-									 int32 changeCounter,
-									 partition_id *unmovable,
-									 partition_id *needUnmounting,
-									 size_t bufferSize);
-bool _kern_supports_setting_partition_name(partition_id partitionID,
-										   int32 changeCounter);
-bool _kern_supports_setting_partition_content_name(partition_id partitionID,
-												   int32 changeCounter,
-												   bool *whileMounted);
-bool _kern_supports_setting_partition_type(partition_id partitionID,
-										   int32 changeCounter);
-bool _kern_supports_setting_partition_parameters(partition_id partitionID,
-												 int32 changeCounter);
-bool _kern_supports_setting_partition_content_parameters(
-	partition_id partitionID, int32 changeCounter, bool *whileMounted);
-bool _kern_supports_initializing_partition(partition_id partitionID,
-										   int32 changeCounter,
-										   const char *diskSystemName);
-bool _kern_supports_creating_child_partition(partition_id partitionID,
-											 int32 changeCounter);
-bool _kern_supports_deleting_child_partition(partition_id partitionID,
-											 int32 changeCounter);
-bool _kern_is_sub_disk_system_for(disk_system_id diskSystemID,
-								  partition_id partitionID,
-								  int32 changeCounter);
-
-status_t _kern_validate_resize_partition(partition_id partitionID,
-										 int32 changeCounter, off_t *size);
-status_t _kern_validate_move_partition(partition_id partitionID,
-									   int32 changeCounter, off_t *newOffset);
-status_t _kern_validate_set_partition_name(partition_id partitionID,
-										   int32 changeCounter, char *name);
-status_t _kern_validate_set_partition_content_name(partition_id partitionID,
-												   int32 changeCounter,
-												   char *name);
-status_t _kern_validate_set_partition_type(partition_id partitionID,
-										   int32 changeCounter,
-										   const char *type);
-status_t _kern_validate_initialize_partition(partition_id partitionID,
-											 int32 changeCounter,
-											 const char *diskSystemName,
-											 char *name,
-											 const char *parameters,
-											 size_t parametersSize);
-status_t _kern_validate_create_child_partition(partition_id partitionID,
-											   int32 changeCounter,
-											   off_t *offset, off_t *size,
-											   const char *type,
-											   const char *parameters,
-											   size_t parametersSize);
-status_t _kern_get_partitionable_spaces(partition_id partitionID,
-										int32 changeCounter,
-										partitionable_space_data *buffer,
-										int32 count, int32 *actualCount);
-status_t _kern_get_next_supported_partition_type(partition_id partitionID,
-												 int32 changeCounter,
-												 int32 *cookie, char *type);
-status_t _kern_get_partition_type_for_content_type(disk_system_id diskSystemID,
-												   const char *contentType,
-												   char *type);
+extern status_t		_kern_validate_resize_partition(partition_id partitionID,
+						int32 changeCounter, off_t *size);
+extern status_t		_kern_validate_move_partition(partition_id partitionID,
+						int32 changeCounter, off_t *newOffset);
+extern status_t		_kern_validate_set_partition_name(partition_id partitionID,
+						int32 changeCounter, char *name);
+extern status_t		_kern_validate_set_partition_content_name(partition_id partitionID,
+						int32 changeCounter, char *name);
+extern status_t		_kern_validate_set_partition_type(partition_id partitionID,
+						int32 changeCounter, const char *type);
+extern status_t		_kern_validate_initialize_partition(partition_id partitionID,
+						int32 changeCounter, const char *diskSystemName,
+						char *name, const char *parameters, size_t parametersSize);
+extern status_t		_kern_validate_create_child_partition(partition_id partitionID,
+						int32 changeCounter, off_t *offset, off_t *size,
+						const char *type, const char *parameters,
+						size_t parametersSize);
+extern status_t		_kern_get_partitionable_spaces(partition_id partitionID,
+						int32 changeCounter, partitionable_space_data *buffer,
+						int32 count, int32 *actualCount);
+extern status_t		_kern_get_next_supported_partition_type(partition_id partitionID,
+						int32 changeCounter, int32 *cookie, char *type);
+extern status_t		_kern_get_partition_type_for_content_type(disk_system_id diskSystemID,
+						const char *contentType, char *type);
 
 // disk device modification
-status_t _kern_prepare_disk_device_modifications(partition_id deviceID);
-status_t _kern_commit_disk_device_modifications(partition_id deviceID,
-												port_id port, int32 token,
-												bool completeProgress);
-status_t _kern_cancel_disk_device_modifications(partition_id deviceID);
-bool _kern_is_disk_device_modified(partition_id deviceID);
-
-status_t _kern_defragment_partition(partition_id partitionID,
-									int32 changeCounter);
-status_t _kern_repair_partition(partition_id partitionID, int32 changeCounter,
-								bool checkOnly);
-status_t _kern_resize_partition(partition_id partitionID, int32 changeCounter,
-								off_t size);
-status_t _kern_move_partition(partition_id partitionID, int32 changeCounter,
-							  off_t newOffset);
-status_t _kern_set_partition_name(partition_id partitionID,
-								  int32 changeCounter, const char *name);
-status_t _kern_set_partition_content_name(partition_id partitionID,
-										  int32 changeCounter,
-										  const char *name);
-status_t _kern_set_partition_type(partition_id partitionID,
-								  int32 changeCounter, const char *type);
-status_t _kern_set_partition_parameters(partition_id partitionID,
-										int32 changeCounter,
-										const char *parameters,
-										size_t parametersSize);
-status_t _kern_set_partition_content_parameters(partition_id partitionID,
-												int32 changeCounter,
-												const char *parameters,
-												size_t parametersSize);
-status_t _kern_initialize_partition(partition_id partitionID,
-									int32 changeCounter,
-									const char *diskSystemName,
-									const char *name, const char *parameters,
-									size_t parametersSize);
-status_t _kern_uninitialize_partition(partition_id partitionID,
-									  int32 changeCounter);
-status_t _kern_create_child_partition(partition_id partitionID,
-									  int32 changeCounter, off_t offset,
-									  off_t size, const char *type,
-									  const char *parameters,
-									  size_t parametersSize,
-									  partition_id *childID);
-status_t _kern_delete_partition(partition_id partitionID, int32 changeCounter);
+extern status_t		_kern_prepare_disk_device_modifications(partition_id deviceID);
+extern status_t		_kern_commit_disk_device_modifications(partition_id deviceID,
+						port_id port, int32 token, bool completeProgress);
+extern status_t		_kern_cancel_disk_device_modifications(partition_id deviceID);
+extern bool			_kern_is_disk_device_modified(partition_id deviceID);
+extern status_t		_kern_defragment_partition(partition_id partitionID,
+						int32 changeCounter);
+extern status_t		_kern_repair_partition(partition_id partitionID, int32 changeCounter,
+						bool checkOnly);
+extern status_t		_kern_resize_partition(partition_id partitionID, int32 changeCounter,
+						off_t size);
+extern status_t		_kern_move_partition(partition_id partitionID, int32 changeCounter,
+						off_t newOffset);
+extern status_t		_kern_set_partition_name(partition_id partitionID,
+						int32 changeCounter, const char *name);
+extern status_t		_kern_set_partition_content_name(partition_id partitionID,
+						int32 changeCounter, const char *name);
+extern status_t		_kern_set_partition_type(partition_id partitionID,
+						int32 changeCounter, const char *type);
+extern status_t		_kern_set_partition_parameters(partition_id partitionID,
+						int32 changeCounter, const char *parameters,
+						size_t parametersSize);
+extern status_t		_kern_set_partition_content_parameters(partition_id partitionID,
+						int32 changeCounter, const char *parameters,
+						size_t parametersSize);
+extern status_t		_kern_initialize_partition(partition_id partitionID,
+						int32 changeCounter, const char *diskSystemName,
+						const char *name, const char *parameters,
+						size_t parametersSize);
+extern status_t		_kern_uninitialize_partition(partition_id partitionID,
+						int32 changeCounter);
+extern status_t		_kern_create_child_partition(partition_id partitionID,
+						int32 changeCounter, off_t offset, off_t size, const char *type,
+						const char *parameters, size_t parametersSize,
+						partition_id *childID);
+extern status_t		_kern_delete_partition(partition_id partitionID, int32 changeCounter);
 
 // jobs
-status_t _kern_get_next_disk_device_job_info(int32 *cookie,
-											 user_disk_device_job_info *info);
-status_t _kern_get_disk_device_job_info(disk_job_id id,
-										user_disk_device_job_info *info);
-status_t _kern_get_disk_device_job_progress_info(disk_job_id id,
-	disk_device_job_progress_info *info);
-status_t _kern_pause_disk_device_job(disk_job_id id);
-status_t _kern_cancel_disk_device_job(disk_job_id id, bool reverse);
+extern status_t		_kern_get_next_disk_device_job_info(int32 *cookie,
+						user_disk_device_job_info *info);
+extern status_t		_kern_get_disk_device_job_info(disk_job_id id,
+						user_disk_device_job_info *info);
+extern status_t		_kern_get_disk_device_job_progress_info(disk_job_id id,
+						disk_device_job_progress_info *info);
+extern status_t		_kern_pause_disk_device_job(disk_job_id id);
+extern status_t		_kern_cancel_disk_device_job(disk_job_id id, bool reverse);
 
 #if 0