winxp驱动程序vc6.0+2003ddk编译错误？

[a294447011294447011]

定义了外部数据：
extern POBJECT_TYPE *IoDriverObjectType;

POBJECT_TYPE *ps=IoDriverObjectType;

错误提示：
LINK : warning LNK4224: /PDBTYPE is no longer supported; ignored
dsys.OBJ : error LNK2001: unresolved external symbol "struct _OBJECT_TYPE * * IoDriverObjectType" (?IoDriverObjectType@@3PAPAU_OBJECT_TYPE@@A)
Debug/dsys.sys : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.

可能缺少哪个lib库连接？希望师傅帮忙？