在zynq开发板zc706上，网络通路由下面三个设备组成：

其中zynq负责对phy进行配置，当zynq上的网络控制器以及phy完成正确配置时，能够看到RJ45上面的黄灯亮，此时表明链路已经通了。如果u-boot中已经设置了IP地址，通过网线就可以ping通电脑，此时会打印host alive这句话。

但是如果板子不是这样做的，比如是下面这种方式：

这里用到了BCM5396网络交换芯片，此时要保证网络链路通就需要对5396和两个PHY进行配置。幸运地是，PHY0由5396进行配置，当我们对5396进行正确配置后，PHY0也就配置完成了，PHY1的配置还是老样子。整个配置可以分为两步走，首先通过SPI总线配置5396，再配置PHY1，完成全部配置后，就能看到RJ45上面的黄灯亮起。

u-boot中需要修改的代码主要涉及三个地方

1、 arch/arm/lib/Board.c

其中board_init_r函数中需要在网络驱动配置前加入配置bcm5396的函数调用，这里我放在了串口驱动配置之后运行。

void board_init_r(gd_t *id, ulong dest_addr)

{

ulong malloc_start;

#if !defined(CONFIG_SYS_NO_FLASH)

ulong flash_size;

#endif

gd->flags |= GD_FLG_RELOC; /* tell others: relocation done */

bootstage_mark_name(BOOTSTAGE_ID_START_UBOOT_R, "board_init_r");

monitor_flash_len = _end_ofs;

/* Enable caches */

enable_caches();

debug("monitor flash len: %08lX\n", monitor_flash_len);

board_init(); /* Setup chipselects */

/*

* TODO: printing of the clock inforamtion of the board is now

* implemented as part of bdinfo command. Currently only support for

* davinci SOC's is added. Remove this check once all the board

* implement this.

*/

#ifdef CONFIG_CLOCKS

set_cpu_clk_info(); /* Setup clock information */

#endif

serial_initialize();

myspi_init(); /*init bcm5396*/

printf("Now running in RAM - U-Boot at: %08lx\n", dest_addr);

#ifdef CONFIG_LOGBUFFER

2、 net/Eth.c

在其中加入配置bcm5396的代码

void myspi_init()

{

XSpiPs Spi;

int i32Option,status;

int i;

unsigned char workBuf[10];

workBuf[0]=0xf0;

workBuf[1]=0x1;

g_SpiConfig = &XSpiPs_ConfigTable[0];

//Initialize the SPI device.

Spi.IsBusy = 0;

Spi.Config.BaseAddress = g_SpiConfig->BaseAddress;

//Spi.StatusHandler = StubStatusHandler;

Spi.SendBufferPtr = NULL;

Spi.RecvBufferPtr = NULL;

Spi.RequestedBytes = 0;

Spi.RemainingBytes = 0;

Spi.IsReady = 0x11111111;

XSpiPs_WriteReg(Spi.Config.BaseAddress,0,0x00020000);

//Initialize the SPI device. end

i32Option = 0x1 | 0x2 | 0x4 | 0x10;

Spi_SetOptions(&Spi, i32Option);

XSpiPs_SetSlaveSelect(&Spi,1 );

XSpiPs_SetClkPrescaler(&Spi, 6 );

workBuf[0]=0xf0;

workBuf[1]=0x1;

workBuf[2]=0;

for(i=0x10;i<=0x1f;i++)

{

status = writeBCM5396(&Spi, i, 0x20, workBuf );

}

printf("*****************Read SPI Reg of 5396******************\r\n");

printf("---BMC Status Registers(PAGE 0x10-0x1F)---\n");

for(i=0x10;i<=0x1f;i++)

{

status = readBCM5396(&Spi, i, 0x28, workBuf );

printf("port=%d,offset=0x28,data=0x%x\n",(i-0x10),workBuf[2]);

printf("port=%d,offset=0x29,data=0x%x\n",(i-0x10),workBuf[3]);

}

printf("---BMC Status Registers(PAGE 0x10-0x1F)---\n\r");

for(i=0x10;i<=0x1f;i++)

{

status = readBCM5396(&Spi, i, 0x20, workBuf );

printf("port=%d,offset=0x20,data=0x%x\n\r",(i-0x10),workBuf[2]);

printf("port=%d,offset=0x21,data=0x%x\n\r",(i-0x10),workBuf[3]);

}

}

3、 drivers/net/Zynq_gem.c

这里的修改是可选项，主要是配置phy，我这里使用的是marvell的88E1111，u-boot中提供的配置方法不起效，于是进行了手动配置。加了phy_detect和negotiat函数

static void phy_negotiat(struct eth_device *dev)

{

struct zynq_gem_priv *priv = dev->priv;

u16 control;

u16 status;

u16 temp;

u16 timeout_counter=0;

printf("Start PHY autonegotiation.\n");

phywrite(dev,priv->phyaddr, 22, 2);

phyread(dev, priv->phyaddr, 21, &control);

control |= 0x0030;

phywrite(dev, priv->phyaddr, 21, control);

phywrite(dev, priv->phyaddr, 22, 0);