你好，我再查看AM572X硬件资料的时候，对网口这部分的描述不是很明白：
10/100/1000 Ethernet
The AM572x GP EVM has two 10/100/1000 Ethernet transceiver from Micrel(KSZ9031RN) that is connected to a dual RJ45 (P5) connector. The two Ethernet interfaces are connected to the switch inside the AM572x processor.
The reset on the transceivers are driven by the board system reset signal ENET0/1_PORZ. A 25MHz crystal drives the clock input of the KSZ9031RN Ethernet PHY.
The PHY address on the MDIO bus is set to 0x00h.
这里的意思是说两个网口只能用一个，不能同时用吗?刚好我对板子进行ping测试的时候，只有一个网口是正常工作的，另一个网口的灯插了网线灯都不亮，我想确定是否板子出了问题还是本来就是只能工作一个。
