6410实现网卡(DM9000A)收发功能及ARP协议实现1. 网卡硬件结构（DM9000A）2. DM9000A硬件接口3. 软件设计4. ARP协议实现5. 代码6. 参考资料：

1. 网卡硬件结构（DM9000A）

网卡的实质就是MAC通过MII接口控制PHY的过程。

MAC主要负责数据帧的构建、数据差错检查、传送控制等。

PHY是物理接口收发器，属于物理层，当它收到MAC过来的数据时，它会去加上校验码，然后按照物理层的规则进行数据编码，再发送到传输介质上，接收过程则相反。

MII：媒体独立接口, “媒体独立”表明MAC一定情况下，任何类型的PHY设备都可以正常工作。

2. DM9000A硬件接口

由上图得到以下信息：

dm9000的片选信号CS#接到Xm0CSn1,Xm0CSn1选择的是Bank1,那么片选的起始地址为0x18000000；cmd引脚接到Xm0ADDR2，那么数据端口地址为0x18000004。

3. 软件设计

3.1 设置SROM Register

读写时序控制

3.2 设置DM9000A相关参数（初始化）

参考uboot

3.3 初步测试

测试结果与设置的一样，说明读写操作正常。

测试代码：

//各种初始化...包括串口初始化等等
//下面是读取一些芯片的出厂信息
tmp = (unsigned char)ior(0x2c);
printf("CHIP Revision:%2xnr", tmp);
tmp = (unsigned char)ior(0x28);
printf("Vendor ID_L:%2x  nr", tmp);
tmp = (unsigned char)ior(0x29);
printf("Vendor ID_H:%2x  nr", tmp);
tmp = (unsigned char)ior(0x2a);
printf("Product ID_L:%2x  nr", tmp);
tmp = (unsigned char)ior(0x2b);
printf("Product ID_H:%2x  nr", tmp);

4. ARP协议实现

4.1 基础知识

4.1.1 以太网的格式

目的MAC地址：接收者的物理地址；源MAC地址：发送者的物理地址；类型：标明高层的数据使用的协议类型；数据：高层的数据；CRC：校验码

4.1.2 ARP功能

在以太网络中，每台计算机的唯一身份标示是MAC地址（物理层的地址），两台计算机要进行通讯，也必须知道对方的MAC地址，但是用户通常只知道对方的IP地址，这个时候，就可以利用ARP（地址解析协议）来向局域网中的所有计算机发送ARP请求包，收到请求包且满足条件的计算机将回复ARP应答包，告知其MAC地址。所以ARP协议是一种利用IP地址或者MAC地址的协议.

4.1.3 ARP格式

 

ARP包分为请求包和应答包，通过OP字段来区别。

4.2 ARP收发

注意字节序！

5. 代码

#include "arp.h"

#define HON(n) ((((u16)((n) & 0xff)) << 8) | (((n) & 0xff00) >> 8))

/*1.发送arp请求包*/
void arp_request()
{
     /*1.构成arp请求包*/
     memcpy(arpbuf.ethhdr.d_mac,host_mac_addr,6);
     memcpy(arpbuf.ethhdr.s_mac,mac_addr,6);
     arpbuf.ethhdr.type = HON(0x0806);
       
     arpbuf.hwtype = HON(1);
     arpbuf.protocol = HON(0x0800);
     
     arpbuf.hwlen = 6;
     arpbuf.protolen = 4;
        
     arpbuf.opcode = HON(1);
 
     memcpy(arpbuf.smac,mac_addr,6);
     memcpy(arpbuf.sipaddr,ip_addr,4);
     memcpy(arpbuf.dipaddr,host_ip_addr,4);

     packet_len = 14+28;
     
     /*2.调用dm9000发送函数，发送应答包*/    
     dm9000_tx(buffer,packet_len);
}


/*2.解析arp应答包，提取mac*/
u8 arp_process()
{

    u32 i;
    
    if (packet_len<28)
        return 0;
    
    memcpy(host_ip_addr,arpbuf.sipaddr,4);
    printf("host ip is : ");
    for(i=0;i<4;i++)
        printf("%03d ",host_ip_addr[i]);
    printf("nr");
    
    memcpy(host_mac_addr,arpbuf.smac,6);
    printf("host mac is : ");
    for(i=0;i<6;i++)
        printf("%02x ",host_mac_addr[i]);
    printf("nr");

}

#include "dm9000.h"
#include "printf.h"
#include "arp.h"


// SROM Controller
#define SROM_BW        (*((volatile unsigned long*)0x70000000))
#define SROM_BC1    (*((volatile unsigned long*)0x70000008))

#define IOADDR        (*((volatile unsigned short*)0x18000000))
#define IODATA        (*((volatile unsigned short*)0x18000004))

u8 *buffer = &arpbuf;

u8 host_mac_addr[6] = {0xff,0xff,0xff,0xff,0xff,0xff};
u8 mac_addr[6] = {9,8,7,6,5,4};//随意
u8 ip_addr[4] = {192,168,1,66};
u8 host_ip_addr[4] = {192,168,1,105};
u16 packet_len;


void delay(int n)
{
    int i,j;
    for(i=0;i<1000;i++)
    {
        for(j=0;j<n;j++)
            ;
    }
}
void iow(u16 reg,u16 data)
{
    IOADDR = reg;
    IODATA = data;
}

u8 ior(u16 reg)
{
    IOADDR = reg;
    return IODATA;
}

void dm9000_reset()
{
    iow(DM9000_GPCR, GPCR_GPIO0_OUT);
    // power on the dm9000    
    iow(DM9000_GPR, 0);
    //dm9000_reset
    iow(DM9000_NCR, (NCR_LBK_INT_MAC | NCR_RST));
    iow(DM9000_NCR, 0); 
    delay(1000);//second reset
    iow(DM9000_NCR, (NCR_LBK_INT_MAC | NCR_RST));
    
    iow(DM9000_NCR, 0);
    delay(1000);
}

int dm9000_probe(void)
{
    u32 id_val;
    id_val = ior(DM9000_VIDL);
    id_val |= ior(DM9000_VIDH) << 8;
    id_val |= ior(DM9000_PIDL) << 16;
    id_val |= ior(DM9000_PIDH) << 24;
    if (id_val == DM9000_ID) {
        printf("dm9000 is found !nr");
        return 0;
    } else {
        printf("dm9000 not found !nr");
        return -1;
    }
}

#define Tacs  2
#define Tcos  2
#define Tacc  3
#define Tcoh  2
#define Tcah  2
#define Tacp  0
int dm9000_init()
{
    int i;
    //设置SROM Register
    SROM_BW &= (~(0xf<<4));
    SROM_BW |= (1<<4);
    SROM_BC1 = (Tacs << 28) | (Tcos << 24) | 
                (Tacc << 16) | (Tcoh << 12) | 
                (Tcah << 8)  | (Tacp << 4);
    
    dm9000_reset();
    dm9000_probe();
    
    //MAC初始化
    /* Program operating register, only internal phy supported */
    iow(DM9000_NCR, 0x0);
    /* TX Polling clear */
    iow(DM9000_TCR, 0);
    /* Less 3Kb, 200us */
    iow(DM9000_BPTR, BPTR_BPHW(3) | BPTR_JPT_600US);
    /* Flow Control : High/Low Water */
    iow(DM9000_FCTR, FCTR_HWOT(3) | FCTR_LWOT(8));
    /* SH FIXME: This looks strange! Flow Control */
    iow(DM9000_FCR, 0x0);
    /* Special Mode */
    iow(DM9000_SMCR, 0);
    /* clear TX status */
    iow(DM9000_NSR, NSR_WAKEST | NSR_TX2END | NSR_TX1END);
    /* Clear interrupt status */
    iow(DM9000_ISR, ISR_ROOS | ISR_ROS | ISR_PTS | ISR_PRS);
    
    /* fill device MAC address registers */
    for (i = 0;i < 6; i++)
        iow(DM9000_PAR+i, mac_addr[i]);
    
    /* Activate DM9000 */
    /* RX enable */
    iow(DM9000_RCR, RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN);
    /* Enable TX/RX interrupt mask */
    iow(DM9000_IMR, IMR_PAR);
}

void dm9000_tx(u8 *data,u32 length)
{
    int i;
    /*禁止中断*/
    iow(DM9000_IMR,0x80);
    
    /*写入发送数据的长度*/
    iow(DM9000_TXPLH, (length >> 8) & 0xff); //高8位
    iow(DM9000_TXPLL, length & 0xff); //低8位
   
    
    /*写入待发送的数据*/
    IOADDR = DM9000_MWCMD;
   
    for(i=0;i<length;i+=2)
    {
        IODATA = data[i] | (data[i+1]<<8);
    }
    
    /*启动发送*/
    iow(DM9000_TCR, TCR_TXREQ); 
    
    /*等待发送结束*/
    while(1)
    {
       u8 status;
       status = ior(DM9000_TCR);
       if((status&0x01)==0x00)
           break;    
    }
    
    /*清除发送状态*/
    iow(DM9000_NSR,0x2c);
    
    /*恢复中断使能*/
    iow(DM9000_IMR,0x81);
}

#define PTK_MAX_LEN 1522
u32 dm9000_rx(u8 *data)
{
    u8 status,len;
    u16 tmp;
    u32 i;
    
    /*判断是否产生中断，且清除*/
    if(ior(DM9000_ISR) & 0x01)
        iow(DM9000_ISR,0x01);
    else
        return 0;
        
    /*空读*/
    ior(DM9000_MRCMDX);
    
    /*读取状态*/
    status = ior(DM9000_MRCMD);
    
    /*读取包长度*/
    len = IODATA;
    
    /*读取包数据*/
    if(len<PTK_MAX_LEN)
    {
       for(i=0;i<len;i+=2)
       {
           tmp = IODATA;
           data[i] = tmp & 0x0ff;
           data[i+1] = (tmp>>8)&0x0ff;
       }
    }
}

void dm9000_arp()
{
    while(1)
    {
        arp_request();
        delay(100);
    }  
}

//初步测试
void dm9000_test(void)
{
    char buf[100] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66 };
    char c;

    printf("DM9000 test :nr");
    printf("press q to exitnr");


    while( 1 ) 
    {
        scanf("%c",&c);
        if (c == 'q' || c == 'Q')
        {
            printf("%s line %dnr", __FUNCTION__, __LINE__);
            return ;
        }
        unsigned char tmp;

     //各种初始化...包括串口初始化等等
     //下面是读取一些芯片的出厂信息
        tmp = (unsigned char)ior(0x2c);
        printf("CHIP Revision:%2xnr", tmp);
        tmp = (unsigned char)ior(0x28);
        printf("Vendor ID_L:%2x  nr", tmp);
        tmp = (unsigned char)ior(0x29);
        printf("Vendor ID_H:%2x  nr", tmp);
        tmp = (unsigned char)ior(0x2a);
        printf("Product ID_L:%2x  nr", tmp);
        tmp = (unsigned char)ior(0x2b);
        printf("Product ID_H:%2x  nr", tmp);
      
        printf("%s line %dnr", __FUNCTION__, __LINE__);
        //dm9000_tx( buf, sizeof(buf) );    
        printf("%s line %dnr", __FUNCTION__, __LINE__);
    }    
}

#if 0
#define EXT_INT_0_CON        (volatile unsigned long*)0x7f008900
#define EXT_INT_0_MASK    (volatile unsigned long*)0x7f008920
#define VIC0INTENABLE    (volatile unsigned long*)0x71200010
#define EINT0_VECTADDR (volatile unsigned long*)0x71200100
#define EXT_INT_0_PEND    (volatile unsigned long*)0x7f008924
#define VIC0ADDRESS (volatile unsigned long*)0x71200f00
#endif

#define GPNCON (*((volatile unsigned long*)0x7F008830)) 
#define GPNDAT (*((volatile unsigned long*)0x7F008834)) 

#define EINT0CON0 (*((volatile unsigned long*)0x7F008900)) 
#define EINT0MASK  (*((volatile unsigned long*)0x7F008920))
#define EINT0PEND (*((volatile unsigned long*)0x7F008924)) 
#define VIC0INTENABLE (*((volatile unsigned long*)0x71200010))
#define EINT7_VECTORADDR (*((volatile unsigned long*)0x71200104))
#define EINT0_VECTADDR   (*((volatile unsigned long*)0x71200100))

#define VIC0ADDRESS (*((volatile unsigned long*)0x71200F00)) 
#define VIC1ADDRESS (*((volatile unsigned long*)0x71300F00)) 
 
#include "arp.h"

void key1_handle()
{
    __asm__(

            "sub lr,lr,#4n"
            "stmfd sp!,{r0-r12,lr}n"
            :
            :
            );

    led_rol();

    EINT0PEND = ~0x0;  
    VIC0ADDRESS = 0;

    __asm__(
            "ldmfd sp!,{r0-r12,pc}^ n"
            :
            :
            );

}

void dm9000_int_issue()
{
 
   __asm__(
            "sub lr,lr,#4n"
            "stmfd sp!,{r0-r12,lr}n"
            :
            :
            );
   

    packet_len = dm9000_rx(buffer);
    arp_process();
  
    EINT0PEND = ~0x0;
    VIC0ADDRESS = 0;
    //VIC1ADDRESS = 0; 
    __asm__(
            "ldmfd sp!,{r0-r12,pc}^ n"
            :
            :
            );
}

void init_irq()
{
    EINT0CON0 |= 0B010;
    EINT0MASK = 0;
    VIC0INTENABLE |= 0X01;
      EINT0_VECTADDR = (unsigned long)key1_handle;
    
    //arp
    GPNCON &= (~(0x2<<14));
    GPNCON |= (0x2<<14);
    EINT0CON0 &= (~(0x7<<12));
    EINT0CON0 |= (0x1<<12);
    EINT0MASK = 0;
    VIC0INTENABLE |= (1<<1);
    EINT7_VECTORADDR = (unsigned long)dm9000_int_issue;
    
    __asm__( 
            "mrc p15,0,r0,c1,c0,0n"
            "orr r0,r0,#(1<<24)n"
            "mcr p15,0,r0,c1,c0,0n"

            "mrs r0,cpsrn"
            "bic r0, r0, #0x80n"
            "msr cpsr_c, r0n"            
            : 
            : 
            );
}

6. 参考资料：

http://www.codeforge.cn/read/243433/dm9000.c__html?go_blog_box=1

http://blog.csdn.net/lzjsqn/article/details/42170375