在U-BOOT中添加一个网卡驱动

移植环境

1，主机环境：VMare下CentOS 5.5 ，1G内存。

2，集成开发环境：Elipse IDE

3，编译编译环境：arm-linux-gcc v4.4.3，arm-none-eabi-gcc v4.5.1。

4，开发板：mini2440，2M nor flash，128M nand flash。

5，u-boot版本：u-boot-2009.08

u-boot-2009.08版本已经对CS8900、RTL8019和DM9000X等网卡有比较完善的代码支持(代码在drivers/net/目录下)，而且在S3C24XX系列中默认对CS8900网卡进行配置使用。而mini2440开发板使用的则是DM9000网卡芯片，所以只需在开发板上添加对DM9000的支持即可。还有一点，以前的 U-boot 对于网络延时部分有问题，需要修改许多地方。但是现在的U-boot 网络
部分已经基本不需要怎么修改了，只有在DM9000 的驱动和NFS 的TIMEOUT 参数上需要稍微修改一下。

4.1，DM9000驱动代码修改

【1】修改static int dm9000_init函数中部分代码，如果不修改这一部分，在使用网卡的时候会报“could not establish link”的错误。

打开/drivers/net/dm9000x.c，定位到377行，修改如下：

 /* Activate DM9000 */
 /* RX enable */
 DM9000_iow(DM9000_RCR, RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN);
 /* Enable TX/RX interrupt mask */
 DM9000_iow(DM9000_IMR, IMR_PAR);

 #if 0 //default to link MII interface
 i = 0;
 while (!(phy_read(1) & 0x20)) { /* autonegation complete bit */
  udelay(1000);
  i++;
  if (i == 1650) { 
   //printf("could not establish link\n");
   //return 0;
   break;
  }
 }
#endif

【2】对于NFS，增加了延时，否则会出现“*** ERROR: Cannot mount”的错误。

打开/net/nfs.c，定位到36行，修改如下：

#if defined(CONFIG_CMD_NET) && defined(CONFIG_CMD_NFS)

#define HASHES_PER_LINE 65 /* Number of "loading" hashes per line */
#define NFS_RETRY_COUNT 30
#define NFS_TIMEOUT (CONFIG_SYS_HZ/1000*2000UL) //2000UL

【3】添加网卡芯片（DM9000）的初始化函数

打开board/samsung/mini2440/mini2440.c，定位到194行附近，文件末尾处，修改如下：

int dram_init (void)
{
 gd->bd->bi_dram[0].start = PHYS_SDRAM_1;
 gd->bd->bi_dram[0].size = PHYS_SDRAM_1_SIZE;

 return 0;
}

extern int dm9000_initialize(bd_t *bis);//implicit declaration of function 'dm9000_initialize'
#ifdef CONFIG_DRIVER_DM9000
int board_eth_init(bd_t *bis)
{
 return dm9000_initialize(bis);
}
#endif

【4】添加串口 Xmodem 传输协议（可不修改）

对于使用串口传输数据到内存的操作，有可能会用到Xmodem协议。但是原本的kermit协议传输就挺好用的，速度也比较快，所以可添加此功能。

打开/common/cmd_load.c，定位到37行，修改如下：

#if defined(CONFIG_CMD_LOADB)
#if defined(ENABLE_CMD_LOADB_X)
static ulong load_serial_xmodem (ulong offset);
#endif
static ulong load_serial_ymodem (ulong offset);
#endif

然后再定位到480行附近，修改如下：

 if (load_baudrate != current_baudrate) {
  printf ("## Switch baudrate to %d bps and press ENTER ...\n",
   load_baudrate);
  udelay(50000);
  gd->baudrate = load_baudrate;
  serial_setbrg ();
  udelay(50000);
  for (;;) {
   if (getc() == '\r')
    break;
  }
 }
#if defined(ENABLE_CMD_LOADB_X)
 if (strcmp(argv[0],"loadx")==0) {
  printf ("## Ready for binary (xmodem) download "
   "to 0x%08lX at %d bps...\n",
   offset,
   load_baudrate);

  addr = load_serial_xmodem (offset);

 } else if (strcmp(argv[0],"loady")==0) {
#else
 if (strcmp(argv[0],"loady")==0) {
#endif
  printf ("## Ready for binary (ymodem) download "
   "to 0x%08lX at %d bps...\n",
   offset,
   load_baudrate);

  addr = load_serial_ymodem (offset);

再定位到998行附近，修改如下：

static int getcxmodem(void) {
 if (tstc())
  return (getc());
 return -1;
}
#if defined(ENABLE_CMD_LOADB_X)
static ulong load_serial_xmodem (ulong offset)
{
 int size;
 char buf[32];
 int err;
 int res;
 connection_info_t info;
 char xmodemBuf[1024];
 ulong store_addr = ~0;
 ulong addr = 0;

 size = 0;
 info.mode = xyzModem_xmodem;
 res = xyzModem_stream_open (&info, &err);
 if (!res) {

  while ((res =
   xyzModem_stream_read (xmodemBuf, 1024, &err)) > 0) {
   store_addr = addr + offset;
   size += res;
   addr += res;
#ifndef CFG_NO_FLASH
   if (addr2info (store_addr)) {
    int rc;

    rc = flash_write ((char *) xmodemBuf,
    store_addr, res);
    if (rc != 0) {
    flash_perror (rc);
    return (~0);
    }
   } else
#endif
   {
    memcpy ((char *) (store_addr), xmodemBuf,
     res);
   }

  }
 } else {
  printf ("%s\n", xyzModem_error (err));
 }

 xyzModem_stream_close (&err);
 xyzModem_stream_terminate (false, &getcxmodem);

 flush_cache (offset, size);

 printf ("## Total Size      = 0x%08x = %d Bytes\n", size, size);
 sprintf (buf, "%X", size);
 setenv ("filesize", buf);

 return offset;
}
#endif
static ulong load_serial_ymodem (ulong offset)

再定位到1169行，修改如下：

#if defined(CONFIG_CMD_LOADB)
U_BOOT_CMD(
 loadb, 3, 0, do_load_serial_bin,
 "load binary file over serial line (kermit mode)",
 "[ off ] [ baud ]\n"
 "    - load binary file over serial line"
 " with offset 'off' and baudrate 'baud'"
);
#if defined(ENABLE_CMD_LOADB_X)
U_BOOT_CMD(
 loadx, 3, 0,    do_load_serial_bin,
 "load binary file over serial line (xmodem mode)",
 "[ off ] [ baud ]\n"
 "    - load binary file over serial line"
 " with offset 'off' and baudrate 'baud'"
);
#endif

U_BOOT_CMD(
 loady, 3, 0, do_load_serial_bin,
 "load binary file over serial line (ymodem mode)",
 "[ off ] [ baud ]\n"
 "    - load binary file over serial line"
 " with offset 'off' and baudrate 'baud'"
);

【5】修改配置文件，在mini2440.h中加入相关定义

打开/include/configs/mini2440.h，定位到60行附近，修改如下：

/*
 * Hardware drivers
 */
#if 0
#define CONFIG_DRIVER_CS8900 1 /* we have a CS8900 on-board */
#define CS8900_BASE  0x19000300
#define CS8900_BUS16  1 /* the Linux driver does accesses as shorts */
#endif 
#define CONFIG_NET_MULTI  1
#define CONFIG_DRIVER_DM9000 1
#define CONFIG_DM9000_BASE 0x20000300 //网卡片选地址
#define DM9000_IO CONFIG_DM9000_BASE
#define DM9000_DATA (CONFIG_DM9000_BASE+4) //网卡数据地址
#define CONFIG_DM9000_NO_SROM  1
//#define CONFIG_DM9000_USE_16BIT
#undef CONFIG_DM9000_DEBUG

注意：
u-boot-2009.08 可以自动检测DM9000网卡的位数，根据开发板原理图可知网卡的数据位为16位，并且网卡位
于CPU的BANK4上，所以只需在 board/samsung/mini2440/lowlevel_init.S中设置 #define B4_BWSCON (DW16) 即
可，不需要此处的 #define CONFIG_DM9000_USE_16BIT 1

给u-boot加上ping命令，用来测试网络通不通

/*
 * Command line configuration.
 */
#include <config_cmd_default.h>

#define CONFIG_CMD_CACHE
#define CONFIG_CMD_DATE
#define CONFIG_CMD_ELF
#define CONFIG_CMD_NAND
#define CONFIG_CMD_JFFS2  /* JFFS2 Support*/
#define CONFIG_CMD_PING /*ping command support*/

恢复被注释掉的网卡MAC地址和修改你合适的开发板IP地址以及内核启动参数：

#define CONFIG_BOOTDELAY 3
#define CONFIG_ETHADDR 08:00:3e:26:0a:5b 
#define CONFIG_NETMASK     255.255.255.0
#define CONFIG_IPADDR  10.1.0.129
#define CONFIG_SERVERIP  10.1.0.128
#define CONFIG_GATEWAYIP 10.1.0.1
#define CONFIG_OVERWRITE_ETHADDR_ONCE
/*#define CONFIG_BOOTFILE "elinos-lart" */

定位到139行附近，加入使能串口传输数据到内存的操作：

#define ENABLE_CMD_LOADB_X    1 //使能串口传输数据到内存的操作

#if defined(CONFIG_CMD_KGDB)
#define CONFIG_KGDB_BAUDRATE 115200  /* speed to run kgdb serial port */
/* what's this ? it's not used anywhere */
#define CONFIG_KGDB_SER_INDEX 1  /* which serial port to use */
#endif

4.2，重新编译u-boot，下载到Nand中从Nand启动，查看启动信息和环境变量并使用ping命令测试网卡，操作如下：

Enter your selection: a
USB host is connected. Waiting a download.

Now, Downloading [ADDRESS:30000000h,TOTAL:154934]
RECEIVED FILE SIZE:  154934 (151KB/S, 1S)
Downloaded file at 0x30000000, size = 154924 bytes
Write to flash ok: skipped size = 0x0, size = 0x25d2c

... ...

nand 方式上电重启后：

U-Boot 2009.08 ( 5�?09 2011 - 15:01:04)

DRAM:  64 MB
Flash:  2 MB
NAND:  128 MiB
In:    serial
Out:   serial
Err:   serial
Net:   dm9000
[u-boot@MINI2440]#

显示下环境变量：

[u-boot@MINI2440]# printenv
bootdelay=3
baudrate=115200
netmask=255.255.255.0
stdin=serial
stdout=serial
stderr=serial
ipaddr=10.1.129
serverip=10.1.0.128
ethact=dm9000

Environment size: 141/131068 bytes

ping测试：
[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 00:00:00:00:00:00
operating at 100M full duplex mode
*** ERROR: `ethaddr' not set
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 00:00:00:00:00:00
operating at 100M full duplex mode
ping failed; host 10.1.0.128 is not alive

需要设定IP地址和MAC地址

[u-boot@MINI2440]# setenv ipaddr 10.1.0.129
[u-boot@MINI2440]# setenv serverip 10.1.0.128
[u-boot@MINI2440]# setenv setenv ethaddr 12:34:56:78:9A:BC
[u-boot@MINI2440]# saveenv
Saving Environment to NAND...
Erasing Nand...
Erasing at 0x4000000000002 --   0% complete.
Writing to Nand... done
[u-boot@MINI2440]#

然后再进行ping测试：

[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 12:34:56:78:9a:bc
operating at 100M full duplex mode
Using dm9000 device
ping failed; host 10.1.0.128 is not alive
[u-boot@MINI2440]#

可以看到，启动信息里面显示了Net：dm9000，printenv查看的环境变量也和include/configs/mini2440.h中设置的一致。但是现在有个问题就是ping不能通过。
经过一段时间在网上搜索，原来有很多人都碰到了这种情况。出现问题的地方可能是DM9000网卡驱动中关闭网卡的地方，如是就试着修改代码如下：

打开drivers/net/dm9000x.c ，定位到456行附近，屏蔽掉dm9000_halt函数中的内容：

/*
  Stop the interface.
  The interface is stopped when it is brought.
*/
static void dm9000_halt(struct eth_device *netdev)
{
#if 0 
 DM9000_DBG("%s\n", __func__);

 /* RESET devie */
 phy_write(0, 0x8000); /* PHY RESET */
 DM9000_iow(DM9000_GPR, 0x01); /* Power-Down PHY */
 DM9000_iow(DM9000_IMR, 0x80); /* Disable all interrupt */
 DM9000_iow(DM9000_RCR, 0x00); /* Disable RX */
#endif 
}

重新编译下载，nand启动，运行结果：

[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 00:00:00:00:00:00
operating at unknown: 0 mode
*** ERROR: `ethaddr' not set
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 00:00:00:00:00:00
operating at unknown: 0 mode
ping failed; host 10.1.0.128 is not alive

[u-boot@MINI2440]# setenv gatewayip 10.1.0.1
[u-boot@MINI2440]# setenv ethaddr 12:34:56:78:9a:bc //MAC地址，随便设
[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 12:34:56:78:9a:bc
operating at unknown: 0 mode
Using dm9000 device
host 10.1.0.128 is alive
[u-boot@MINI2440]# saveenv
Saving Environment to NAND...
Erasing Nand...
Erasing at 0x4000000000002 --   0% complete.
Writing to Nand... done

[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 12:34:56:78:9a:bc
operating at unknown: 0 mode
Using dm9000 device
host 10.1.0.128 is alive
[u-boot@MINI2440]#

结果，只是第一次ping不通，以后都是可以ping通的(据网友们说这是正常的)。

4.3，tftp功能测试

首先需要将友善官方移植好的有关mini2440的内核文件zImage_T35复制到linux 宿主机的/tftpboot目录下，因为u-boot默认的此目录，然后执行：

[u-boot@MINI2440]# tftp 0x30008000 zImage_T35
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 12:34:56:78:9a:bc
operating at unknown: 0 mode
Using dm9000 device
TFTP from server 10.1.0.128; our IP address is 10.1.0.129
Filename 'zImage_T35'.
Load address: 0x30008000
Loading: T ################################################T #################
         #############T T ######################T ##############################
T T
         ########
done
Bytes transferred = 2022348 (1edbcc hex)
[u-boot@MINI2440]#

至此DM9000网卡驱动移植成功。但是还发现一个问题："这里之前还是"operating at 100M full duplex mode"，而现在怎么是"operating at unknown: 0 mode"？原来是dm9000的phy_read(int reg)函数延时出了问题，现操作如下：

打开/drivers/net/dm9000x.c，定位到595行附近，修改如下：

/*
   Read a word from phyxcer
*/
static u16
phy_read(int reg)
{
 u16 val;

 /* Fill the phyxcer register into REG_0C */
 DM9000_iow(DM9000_EPAR, DM9000_PHY | reg);
 DM9000_iow(DM9000_EPCR, 0xc); /* Issue phyxcer read command */
 udelay(1000); //udelay(100);   /* Wait read complete */
 DM9000_iow(DM9000_EPCR, 0x0); /* Clear phyxcer read command */
 val = (DM9000_ior(DM9000_EPDRH) << 8) | DM9000_ior(DM9000_EPDRL);

 /* The read data keeps on REG_0D & REG_0E */
 DM9000_DBG("phy_read(0x%x): 0x%x\n", reg, val);
 return val;
}
重新编译下载后：

[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 12:34:56:78:9a:bc
operating at unknown: 15 mode
Using dm9000 device
ping failed; host 10.1.0.128 is not alive
[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 12:34:56:78:9a:bc
operating at 100M full duplex mode
Using dm9000 device
host 10.1.0.128 is alive
[u-boot@MINI2440]#
可以看到"operating at 100M full duplex mode"这样的信息了

上面还有一个问题，就是问什么第一次ping不通呢?经过尝试，操作如下：

打开/drivers/net/dm9000x.c，定位到377行，修改如下：

 /* Activate DM9000 */
 /* RX enable */
 DM9000_iow(DM9000_RCR, RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN);
 /* Enable TX/RX interrupt mask */
 DM9000_iow(DM9000_IMR, IMR_PAR);

 #if 1 //internet delay loop
 i = 0;
 while (!(phy_read(1) & 0x20)) { /* autonegation complete bit */
  udelay(1000);
  i++;
  if (i == 3000) { 
   printf("could not establish link\n");
   return 0;
   //break;
  }
 }
#endif

修改后重新编译下载：

[u-boot@MINI2440]# ping 10.1.0.128
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 12:34:56:78:9a:bc
operating at 100M full duplex mode
Using dm9000 device
host 10.1.0.128 is alive
[u-boot@MINI2440]#

OK! 第一次ping不通的问题解决了！