针对VITIS无法支持的以太网芯片的LWIP库修改方法以（YT8531DH为例）

第一步:自定义LWIP库版本号修改

复制一份你安装的版本的软件最新的库

修改如下文件：

修改lwip211.mld文件中的版本标识（如将OPTION VERSION =1.5;改为2.0），尽量改大一些，避免Vitis环境缓存旧库

第二步:修改LWIP库文件新增以太网芯片的适配

需要修改xemacpsif_physpeed.c或者xaxiemacif_physpeed.c文件，分别对应了ARM自带的以太网接口使用MIO实现以太网功能LWIP部分修改和PL部分基于AXI总线gig_ethernet_pcs_pma 以太网IP 扩展以太网使用 LWIP需要修改的文件。

1:添加，YT8531的PHY标识符

xemacpsif_physpeed.c或者xaxiemacif_physpeed.c文件中增加如下定义

#define PHY_YT8531_IDENTIFIER               0x4f51

2:ARM自带的以太网接口xemacpsif_physpeed.c文件修改

第一个修改位置：

void detect_phy(XEmacPs *xemacpsp)
{
    u16_t phy_reg;
    u32_t phy_addr;
    u32_t emacnum;

    if (xemacpsp->Config.BaseAddress == XPAR_XEMACPS_0_BASEADDR)
        emacnum = 0;
    else
        emacnum = 1;
    for (phy_addr = 31; phy_addr > 0; phy_addr--) {
        XEmacPs_PhyRead(xemacpsp, phy_addr, PHY_DETECT_REG,
                            &phy_reg);

        if ((phy_reg != 0xFFFF) &&
            ((phy_reg & PHY_DETECT_MASK) == PHY_DETECT_MASK)) {
            /* Found a valid PHY address */
            LWIP_DEBUGF(NETIF_DEBUG, ("XEmacPs detect_phy: PHY detected at address %d.\r\n",
                                                                    phy_addr));
            if (emacnum == 0)
                phymapemac0[phy_addr] = TRUE;
            else
                phymapemac1[phy_addr] = TRUE;

            XEmacPs_PhyRead(xemacpsp, phy_addr, PHY_IDENTIFIER_1_REG,
                            &phy_reg);
            if ((phy_reg != PHY_MARVELL_IDENTIFIER) &&
                (phy_reg != PHY_TI_IDENTIFIER) &&
                (phy_reg != PHY_REALTEK_IDENTIFIER) &&
                (phy_reg != PHY_YT8531_IDENTIFIER))
                
                 {
                xil_printf("WARNING: Not a Marvell or TI or Realtek or YT8531 Ethernet PHY. Please verify the initialization sequence\r\n");
            }
        }
    }
}
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第二个修改的位置：

static u32_t get_IEEE_phy_speed(XEmacPs *xemacpsp, u32_t phy_addr)
{
    u16_t phy_identity;
    u32_t RetStatus;

    XEmacPs_PhyRead(xemacpsp, phy_addr, PHY_IDENTIFIER_1_REG,
                    &phy_identity);
    if (phy_identity == PHY_TI_IDENTIFIER) {
        RetStatus = get_TI_phy_speed(xemacpsp, phy_addr);
    } else if (phy_identity == PHY_REALTEK_IDENTIFIER) {
        RetStatus = get_Realtek_phy_speed(xemacpsp, phy_addr);
    } else if (phy_identity == PHY_YT8531_IDENTIFIER) {
        RetStatus = get_YT8531_phy_speed(xemacpsp, phy_addr);
    } else {
        RetStatus = get_Marvell_phy_speed(xemacpsp, phy_addr);
    }

    return RetStatus;
}
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第三个修改位置：

复制代码中已经有的get_Realtek_phy_speed函数，修改为，get_YT8531_phy_speed函数，并且对读取的速率寄存器部分修改，读取的值含义对照YT8531芯片手册进行速率部分转换为1000/100/10三种速度

static u32_t get_YT8531_phy_speed(XEmacPs *xemacpsp, u32_t phy_addr)
{
    u16_t control;
    u16_t status;
    u16_t status_speed;
    u32_t timeout_counter = 0;
    u32_t temp_speed;

xil_printf("Start YT8531 PHY autonegotiation \r\n");

    XEmacPs_PhyRead(xemacpsp, phy_addr, IEEE_AUTONEGO_ADVERTISE_REG, &control);
    control |= IEEE_ASYMMETRIC_PAUSE_MASK;
    control |= IEEE_PAUSE_MASK;
    control |= ADVERTISE_100;
    control |= ADVERTISE_10;
    XEmacPs_PhyWrite(xemacpsp, phy_addr, IEEE_AUTONEGO_ADVERTISE_REG, control);

    XEmacPs_PhyRead(xemacpsp, phy_addr, IEEE_1000_ADVERTISE_REG_OFFSET,
                    &control);
    control |= ADVERTISE_1000;
    XEmacPs_PhyWrite(xemacpsp, phy_addr, IEEE_1000_ADVERTISE_REG_OFFSET,
                    control);

    XEmacPs_PhyRead(xemacpsp, phy_addr, IEEE_CONTROL_REG_OFFSET, &control);
    control |= IEEE_CTRL_AUTONEGOTIATE_ENABLE;
    control |= IEEE_STAT_AUTONEGOTIATE_RESTART;
    XEmacPs_PhyWrite(xemacpsp, phy_addr, IEEE_CONTROL_REG_OFFSET, control);

    XEmacPs_PhyRead(xemacpsp, phy_addr, IEEE_CONTROL_REG_OFFSET, &control);
    control |= IEEE_CTRL_RESET_MASK;
    XEmacPs_PhyWrite(xemacpsp, phy_addr, IEEE_CONTROL_REG_OFFSET, control);

    while (1) {
        XEmacPs_PhyRead(xemacpsp, phy_addr, IEEE_CONTROL_REG_OFFSET, &control);
        if (control & IEEE_CTRL_RESET_MASK)
            continue;
        else
            break;
    }

    XEmacPs_PhyRead(xemacpsp, phy_addr, IEEE_STATUS_REG_OFFSET, &status);

    xil_printf("Waiting for PHY to complete autonegotiation.\r\n");

    while ( !(status & IEEE_STAT_AUTONEGOTIATE_COMPLETE) ) {
        sleep(1);
        timeout_counter++;

        if (timeout_counter == 30) {
            xil_printf("Auto negotiation error \r\n");
            return XST_FAILURE;
        }
        XEmacPs_PhyRead(xemacpsp, phy_addr, IEEE_STATUS_REG_OFFSET, &status);
    }
    xil_printf("autonegotiation complete \r\n");

//YT8531 REG
    XEmacPs_PhyRead(xemacpsp, phy_addr,0X11,&status_speed);
    status_speed = status_speed>>8;

    if (status_speed & 0x04) {
        temp_speed = status_speed & 0xc0;

        if (temp_speed == 0x80)
            return 1000;
        else if(temp_speed == 0x40)
            return 100;
        else
            return 10;

    }
    return XST_FAILURE;
}
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3:PL扩展xaxiemacif_physpeed.c文件的修改

第一个修改位置：

detect_phy函数中增加对该PHY的识别
static int detect_phy(XAxiEthernet *xaxiemacp)
{
    u16 phy_reg;
    u16 phy_id;
    u32 phy_addr;

    for (phy_addr = 31; phy_addr > 0; phy_addr--)
    {
        if(PHY_ADDR_CNT_UP)
            phy_addr = 32 - phy_addr;

        XAxiEthernet_PhyRead(xaxiemacp, phy_addr, PHY_DETECT_REG,
                                &phy_reg);

        if ((phy_reg != 0xFFFF) &&
            ((phy_reg & PHY_DETECT_MASK) == PHY_DETECT_MASK)) {
            /* Found a valid PHY address */
            LWIP_DEBUGF(NETIF_DEBUG, ("XAxiEthernet detect_phy: PHY detected at address %d.\r\n", phy_addr));
            LWIP_DEBUGF(NETIF_DEBUG, ("XAxiEthernet detect_phy: PHY detected.\r\n"));
            XAxiEthernet_PhyRead(xaxiemacp, phy_addr, PHY_IDENTIFIER_1_REG,
                                        &phy_reg);
            if ((phy_reg != PHY_MARVELL_IDENTIFIER) &&
                    (phy_reg != TI_PHY_IDENTIFIER) &&
                    (phy_reg != PHY_REALTEK_IDENTIFIER)&&
                    (phy_reg != PHY_YT8531_IDENTIFIER)
                    ){
                xil_printf("WARNING: Not a Marvell or TI Ethernet PHY. Please verify the initialization sequence\r\n");
            }
            phyaddrforemac = phy_addr;
            return phy_addr;
        }

        XAxiEthernet_PhyRead(xaxiemacp, phy_addr, PHY_IDENTIFIER_1_REG,
                &phy_id);

        if (phy_id == PHY_XILINX_PCS_PMA_ID1) {
            XAxiEthernet_PhyRead(xaxiemacp, phy_addr, PHY_IDENTIFIER_2_REG,
                    &phy_id);
            if (phy_id == PHY_XILINX_PCS_PMA_ID2) {
                /* Found a valid PHY address */
                LWIP_DEBUGF(NETIF_DEBUG, ("XAxiEthernet detect_phy: PHY detected at address %d.\r\n",
                            phy_addr));
                phyaddrforemac = phy_addr;
                return phy_addr;
            }
        }
    }

    LWIP_DEBUGF(NETIF_DEBUG, ("XAxiEthernet detect_phy: No PHY detected.  Assuming a PHY at address 0\r\n"));

        /* default to zero */
    return 0;
}
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第二个修改位置:

get_IEEE_phy_speed函数中，增加对以太网芯片速率识别的调用

unsigned get_IEEE_phy_speed(XAxiEthernet *xaxiemacp)
{
    u16 phy_identifier;
    u16 phy_model;
    u8 phytype;

#ifdef XPAR_AXIETHERNET_0_BASEADDR
    u32 phy_addr = detect_phy(xaxiemacp);

    /* Get the PHY Identifier and Model number */
    XAxiEthernet_PhyRead(xaxiemacp, phy_addr, PHY_IDENTIFIER_1_REG, &phy_identifier);
    XAxiEthernet_PhyRead(xaxiemacp, phy_addr, PHY_IDENTIFIER_2_REG, &phy_model);

/* Depending upon what manufacturer PHY is connected, a different mask is
 * needed to determine the specific model number of the PHY. */
    if (phy_identifier == MARVEL_PHY_IDENTIFIER) {
        phy_model = phy_model & MARVEL_PHY_MODEL_NUM_MASK;

        if (phy_model == MARVEL_PHY_88E1116R_MODEL) {
            return get_phy_speed_88E1116R(xaxiemacp, phy_addr);
        } else if (phy_model == MARVEL_PHY_88E1111_MODEL) {
            return get_phy_speed_88E1111(xaxiemacp, phy_addr);
        }
    }
    else if (phy_identifier == TI_PHY_IDENTIFIER) {
        phy_model = phy_model & TI_PHY_DP83867_MODEL;
        phytype = XAxiEthernet_GetPhysicalInterface(xaxiemacp);

        if (phy_model == TI_PHY_DP83867_MODEL && phytype == XAE_PHY_TYPE_SGMII) {
            return get_phy_speed_TI_DP83867_SGMII(xaxiemacp, phy_addr);
        }

        if (phy_model == TI_PHY_DP83867_MODEL) {
            return get_phy_speed_TI_DP83867(xaxiemacp, phy_addr);
        }
    }
    else if(phy_identifier == PHY_YT8531_IDENTIFIER)
    {
        return get_YT8531_phy_speed(xaxiemacp, phy_addr);

    }
    else if(phy_identifier == PHY_REALTEK_IDENTIFIER)
    {
        return get_Realtek_phy_speed(xaxiemacp, phy_addr);
    }
    else {
        LWIP_DEBUGF(NETIF_DEBUG, ("XAxiEthernet get_IEEE_phy_speed: Detected PHY with unknown identifier/model.\r\n"));
    }
#endif
#ifdef PCM_PMA_CORE_PRESENT
    return get_phy_negotiated_speed(xaxiemacp, phy_addr);
#endif
}
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第三个修改位置：

该代码需要复制xemacpsif_physpeed.c代码中已经有的get_Realtek_phy_speed函数，修改为，get_YT8531_phy_speed函数，并且基于AXI接口读取寄存器的函数进行修改，最后对读取的速率寄存器部分修改，读取的值含义对照YT8531芯片手册进行速率部分转换为1000/100/10三种速度

static u32_t get_YT8531_phy_speed(XAxiEthernet *xaxiemacp, u32_t phy_addr)
{
    u16_t control;
    u16_t status;
    u16_t status_speed;
    u32_t timeout_counter = 0;
    u32_t temp_speed;

    xil_printf("Start YT8531 PHY autonegotiation \r\n");

    XAxiEthernet_PhyRead(xaxiemacp, phy_addr, IEEE_AUTONEGO_ADVERTISE_REG, &control);
    control |= IEEE_ASYMMETRIC_PAUSE_MASK;
    control |= IEEE_PAUSE_MASK;
    control |= ADVERTISE_100;
    control |= ADVERTISE_10;
    XAxiEthernet_PhyWrite(xaxiemacp, phy_addr, IEEE_AUTONEGO_ADVERTISE_REG, control);

    XAxiEthernet_PhyRead(xaxiemacp, phy_addr, IEEE_1000_ADVERTISE_REG_OFFSET,
                    &control);
    control |= ADVERTISE_1000;
    XAxiEthernet_PhyWrite(xaxiemacp, phy_addr, IEEE_1000_ADVERTISE_REG_OFFSET,
                    control);

    XAxiEthernet_PhyRead(xaxiemacp, phy_addr, IEEE_CONTROL_REG_OFFSET, &control);
    control |= IEEE_CTRL_AUTONEGOTIATE_ENABLE;
    control |= IEEE_STAT_AUTONEGOTIATE_RESTART;
    XAxiEthernet_PhyWrite(xaxiemacp, phy_addr, IEEE_CONTROL_REG_OFFSET, control);

    XAxiEthernet_PhyRead(xaxiemacp, phy_addr, IEEE_CONTROL_REG_OFFSET, &control);
    control |= IEEE_CTRL_RESET_MASK;
    XAxiEthernet_PhyWrite(xaxiemacp, phy_addr, IEEE_CONTROL_REG_OFFSET, control);

    while (1) {
        XAxiEthernet_PhyRead(xaxiemacp, phy_addr, IEEE_CONTROL_REG_OFFSET, &control);
        if (control & IEEE_CTRL_RESET_MASK)
            continue;
        else
            break;
    }

    XAxiEthernet_PhyRead(xaxiemacp, phy_addr, IEEE_STATUS_REG_OFFSET, &status);

    xil_printf("Waiting for PHY to complete autonegotiation.\r\n");

    while ( !(status & IEEE_STAT_AUTONEGOTIATE_COMPLETE) ) {
        sleep(1);
        timeout_counter++;

        if (timeout_counter == 30) {
            xil_printf("Auto negotiation error \r\n");
            return XST_FAILURE;
        }
        XAxiEthernet_PhyRead(xaxiemacp, phy_addr, IEEE_STATUS_REG_OFFSET, &status);
    }
    xil_printf("autonegotiation complete \r\n");

    XAxiEthernet_PhyRead(xaxiemacp, phy_addr,0X11,&status_speed);
    status_speed = status_speed>>8;

    if (status_speed & 0x04) {
        temp_speed = status_speed & 0xc0;

        if (temp_speed == 0x80)
            return 1000;
        else if(temp_speed == 0x40)
            return 100;
        else
            return 10;

    }

    return XST_FAILURE;
}
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