LS1046支持SGMII网口，DEMO板设计SGMII+PHY+RJ45的方式出网口，MIDO接口访问PHY芯片，会设置PHY芯片的MIDO地址。

而实际在板间或者CPU之间，是直接通过SGMII对接通讯的，没有PHY芯片，则不要配置PHY芯片MIDO地址。必须配置SGMII网口的PHY为FIXED-PHY，并且关闭SGMII内部PHY自协商模式，方可通讯。

修改设备树配置文件 fsl-ls1046a-frwy.dts
&fman0 {

/*eth0 FM3 RGMII 调试网口 */
ethernet@e4000 {
phy-handle = <&rgmii_phy1>;
phy-connection-type = “rgmii”;
};

/eth1 FM6 SGMII 对应VP0/
ethernet@ea000 {
fixed-link = <0 1 1000 0 0>;
phy-connection-type = “sgmii”;
};

/eth2 FM2 SGMII 对应VP1/
ethernet@e2000 {
fixed-link = <0 1 1000 0 0>;
phy-connection-type = “sgmii”;
};

/eth3 FM5 SGMII 对应VP2/
ethernet@e8000 {
fixed-link = <0 1 1000 0 0>;
phy-connection-type = “sgmii”;
};

/eth4 FM9 SGMII 对应VP3/
ethernet@f0000 {
fixed-link = <0 1 1000 0 0>;
phy-connection-type = “sgmii”;
};

/eth5 FM10 SGMII 主备VP网口/
ethernet@f2000 {
fixed-link = <0 1 1000 0 0>;
phy-connection-type = “sgmii”;
};

mdio@fc000 {
rgmii_phy1: ethernet-phy@1 {
reg = <0x1>;
};
};
};

关闭SGMII自协商