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鏈?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！
接下来将进入u-boot的第五阶段，为u-boot-2009.08增加yaffs2文件系统。