questions about serial smart card reader driver。gloomyyyy,help me!!

何为root enumerated device?
何为legacy driver?
我的问题是这样的：
小弟要为 non_pnp的serial smart card reader开发2k pro下的驱动，
有几点不明白的地方：
1：驱动的设计有什么特殊之处？
according to Walte Oney:
If your device does not provide a PnP id, you'll install your driver as legacy driver.
//何为legacy driver?
The root enumerator acts as the bus driver for your device.
//何为root enumerated device?
这是怎么实现的呢？
how does the PnP Manager loads my driver?
2：驱动的安装如何来实现？串口的选择在驱动中来实现还是用co-installer来实现好？

Your INF file will use legacy syntax in the model statement, as in this example:

"Acme Widget Model 102 (Legacy)"=DriverInstall,*XYZ1234

对于没有pnp id的设备，这个*xyz1234到底应该怎么来写？
any clue on Legacy Syntax??
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小弟实在是万分焦急，望各位大侠不吝赐教！！！
如果哪位兄弟做过类似的驱动，希望拉小弟一把，不胜感激！！！
急求 类似相关的的源码
TIA！！！！
anlai.jia@todos.com.cn