一，支持下載yaffs2文件系統(tǒng)

1、在include/configs/apple2440.h頭文件中定義一個管理對Yaffs2支持的宏和開啟u-boot中對Nand Flash默認(rèn)分區(qū)的宏，如下：
gedit include/configs/apple2440.h
//定義一個管理對Yaffs2支持的宏
#define CONFIG_MTD_NAND_YAFFS2   1
//開啟Nand Flash默認(rèn)分區(qū)，注意此處的分區(qū)要和你的內(nèi)核中的分區(qū)保持一致
#define MTDIDS_DEFAULT "nand0=nandflash0"
#define MTDPARTS_DEFAULT "mtdparts=nandflash0:256k(bootloader)," \
                                                            "3m(kernel)," \
                                                            "-(root)"
 
2、在原來對Nand操作的命令集列表中添加Yaffs2對Nand的寫命令，如下：
gedit common/cmd_nand.c
在函數(shù)U_BOOT_CMD中添加如下：
//注意：這里只添加了yaffs2的寫命令，因為我們只用u-boot下載(即寫)功能，所以我們沒有添加yaffs2讀的命令
U_BOOT_CMD(nand, CONFIG_SYS_MAXARGS, 1, do_nand,
    "NAND sub-system",
    "info - show available NAND devices\n"
    "nand device [dev] - show or set current device\n"
    "nand read - addr off|partition size\n"
    "nand write - addr off|partition size\n"
    " read/write 'size' bytes starting at offset 'off'\n"
    " to/from memory address 'addr', skipping bad blocks.\n"

//注意：這里只添加了yaffs2的寫命令，因為我們只用u-boot下載(即寫)功能，所以我們沒有添加yaffs2讀的命令
#if defined(CONFIG_MTD_NAND_YAFFS2)
    "nand write[.yaffs2] - addr off|partition size - write `size' byte yaffs image\n"
    " starting at offset off' from memory address addr' (.yaffs2 for 512+16 NAND)\n"
#endif

    "nand erase [clean] [off size] - erase 'size' bytes from\n"
    " offset 'off' (entire device if not specified)\n"
    "nand bad - show bad blocks\n"
    "nand dump[.oob] off - dump page\n"
    "nand scrub - really clean NAND erasing bad blocks (UNSAFE)\n"
    "nand markbad off [...] - mark bad block(s) at offset (UNSAFE)\n"
    "nand biterr off - make a bit error at offset (UNSAFE)"
#ifdef CONFIG_CMD_NAND_LOCK_UNLOCK
    "\n"
    "nand lock [tight] [status]\n"
    " bring nand to lock state or display locked pages\n"
    "nand unlock [offset] [size] - unlock section"
#endif
);
 
3,接著，在該文件中對nand操作的do_nand函數(shù)中添加yaffs2對nand的操作，如下:
 if (strncmp(cmd, "read", 4) == 0 || strncmp(cmd, "write", 5) == 0)
    {
        int read;

        if (argc < 4)
            goto usage;

        addr = (ulong)simple_strtoul(argv[2], NULL, 16);

        read = strncmp(cmd, "read", 4) == 0; /* 1 = read, 0 = write */
        printf("\nNAND %s: ", read ? "read" : "write");
        if (arg_off_size(argc - 3, argv + 3, nand, &off, &size) != 0)
            return 1;

        s = strchr(cmd, '.');
        if (!s || !strcmp(s, ".jffs2") || !strcmp(s, ".e") || !strcmp(s, ".i"))
        {
            if (read)
                ret = nand_read_skip_bad(nand, off, &size, (u_char *)addr);
            else
                ret = nand_write_skip_bad(nand, off, &size, (u_char *)addr);
        }

//添加yaffs2相關(guān)操作，注意該處又關(guān)聯(lián)到nand_write_skip_bad函數(shù)

#if defined(CONFIG_MTD_NAND_YAFFS2)
        else if (s != NULL && (!strcmp(s, ".yaffs2")))
        {
            nand->rw_oob = 1;
            nand->skipfirstblk = 1;
            ret = nand_write_skip_bad(nand,off,&size,(u_char *)addr);
            nand->skipfirstblk = 0;
            nand->rw_oob = 0;
        }
#endif

        else if (!strcmp(s, ".oob"))
        {
            /* out-of-band data */
            mtd_oob_ops_t ops =
            {
                .oobbuf = (u8 *)addr,
                .ooblen = size,
                .mode = MTD_OOB_RAW
            };

            if (read)
                ret = nand->read_oob(nand, off, &ops);
            else
                ret = nand->write_oob(nand, off, &ops);
        }
        else
        {
            printf("Unknown nand command suffix '%s'.\n", s);
            return 1;
        }

        printf(" %zu bytes %s: %s\n", size, read ? "read" : "written", ret ? "ERROR" : "OK");

        return ret == 0 ? 0 : 1;
    }

在include/linux/mtd/mtd.h頭文件的mtd_info結(jié)構(gòu)體中添加上面用到rw_oob和skipfirstblk數(shù)據(jù)成員，如下：
#gedit include/linux/mtd/mtd.h   //在mtd_info結(jié)構(gòu)體中添加
 

#if defined(CONFIG_MTD_NAND_YAFFS2)
    u_char rw_oob;
    u_char skipfirstblk;
#endif
 

 
在第二步關(guān)聯(lián)的nand_write_skip_bad函數(shù)中添加對Nand OOB的相關(guān)操作，如下：
#gedit drivers/mtd/nand/nand_util.c  //在nand_write_skip_bad函數(shù)中添加
 

int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, u_char *buffer)
{
    int rval;
    size_t left_to_write = *length;
    size_t len_incl_bad;
    u_char *p_buffer = buffer;

#if defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support
    if(nand->rw_oob==1)   
    {
        size_t oobsize = nand->oobsize;
        size_t datasize = nand->writesize;
        int datapages = 0;

        if (((*length)%(nand->oobsize+nand->writesize)) != 0)
        {
         printf ("Attempt to write error length data!\n");
         return -EINVAL;
     }

        datapages = *length/(datasize+oobsize);
        *length = datapages*datasize;
        left_to_write = *length;
    }
#endif

    /* Reject writes, which are not page aligned */
    if ((offset & (nand->writesize - 1)) != 0 ||
     (*length & (nand->writesize - 1)) != 0) {
        printf ("Attempt to write non page aligned data\n");
        return -EINVAL;
    }

    len_incl_bad = get_len_incl_bad (nand, offset, *length);

    if ((offset + len_incl_bad) >= nand->size) {
        printf ("Attempt to write outside the flash area\n");
        return -EINVAL;
    }

#if !defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support
    if (len_incl_bad == *length) {
        rval = nand_write (nand, offset, length, buffer);
        if (rval != 0)
            printf ("NAND write to offset %llx failed %d\n",
                offset, rval);

        return rval;
    }
#endif

    while (left_to_write > 0) {
        size_t block_offset = offset & (nand->erasesize - 1);
        size_t write_size;

        WATCHDOG_RESET ();

        if (nand_block_isbad (nand, offset & ~(nand->erasesize - 1))) {
            printf ("Skip bad block 0x%08llx\n",
                offset & ~(nand->erasesize - 1));
            offset += nand->erasesize - block_offset;
            continue;
        }

#if defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support
        if(nand->skipfirstblk==1)   
        {
            nand->skipfirstblk=0;
            printf ("Skip the first good block %llx\n", offset & ~(nand->erasesize - 1));
            offset += nand->erasesize - block_offset;
            continue;
        }
#endif

        if (left_to_write < (nand->erasesize - block_offset))
            write_size = left_to_write;
        else
            write_size = nand->erasesize - block_offset;

        printf("\rWriting at 0x%llx -- ",offset); //add yaffs2 file system support

        rval = nand_write (nand, offset, &write_size, p_buffer);
        if (rval != 0) {
            printf ("NAND write to offset %llx failed %d\n",
                offset, rval);
            *length -= left_to_write;
            return rval;
        }

        left_to_write -= write_size;
        printf("%d%% is complete.",100-(left_to_write/(*length/100)));
        offset += write_size;

#if defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support
        if(nand->rw_oob==1)   
        {
            p_buffer += write_size+(write_size/nand->writesize*nand->oobsize);
        }
        else   
        {
            p_buffer += write_size;
        }
#else
        p_buffer += write_size;
#endif

    }

    return 0;
}
 

在上一步nand_write_skip_bad函數(shù)中我們看到又對nand_write函數(shù)進行了訪問，所以這一步是到nand_write函數(shù)中添加對yaffs2的支持，如下： #gedit drivers/mtd/nand/nand_base.c  //在nand_write函數(shù)中添加
 
static int nand_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const uint8_t *buf)
{
    struct nand_chip *chip = mtd->priv;
    int ret;

#if defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support

    int oldopsmode = 0;

    if(mtd->rw_oob==1)   
    {
        int i = 0;
        int datapages = 0;

        size_t oobsize = mtd->oobsize;
        size_t datasize = mtd->writesize;

        uint8_t oobtemp[oobsize];
        datapages = len / (datasize);

        for(i = 0; i < (datapages); i++)   
        {
            memcpy((void *)oobtemp, (void *)(buf + datasize * (i + 1)), oobsize);
            memmove((void *)(buf + datasize * (i + 1)), (void *)(buf + datasize * (i + 1) + oobsize), (datapages - (i + 1)) * (datasize) + (datapages - 1) * oobsize);
            memcpy((void *)(buf+(datapages) * (datasize + oobsize) - oobsize), (void *)(oobtemp), oobsize);
        }
    }
#endif

    /* Do not allow reads past end of device */
    if ((to + len) > mtd->size)
        return -EINVAL;
    if (!len)
        return 0;

    nand_get_device(chip, mtd, FL_WRITING);

    chip->ops.len = len;
    chip->ops.datbuf = (uint8_t *)buf;

#if defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support

    if(mtd->rw_oob!=1)   
    {
        chip->ops.oobbuf = NULL;
    }
    else   
    {
        chip->ops.oobbuf = (uint8_t *)(buf + len);
        chip->ops.ooblen = mtd->oobsize;
        oldopsmode = chip->ops.mode;
        chip->ops.mode = MTD_OOB_RAW;
    }
#else
    chip->ops.oobbuf = NULL;
#endif

    ret = nand_do_write_ops(mtd, to, &chip->ops);

    *retlen = chip->ops.retlen;

    nand_release_device(mtd);

#if defined(CONFIG_MTD_NAND_YAFFS2) //add yaffs2 file system support

    chip->ops.mode = oldopsmode;
#endif

    return ret;
}
 

OK，對yaffs2支持的代碼已修改完畢，重新編譯u-boot并下載到nand中，啟動開發(fā)板，在u-boot的命令行輸入:nand help查看nand的命令，可以看到多了一個nand write[.yaffs2]的命令，這個就是用來下載yaffs2文件系統(tǒng)到nand中的命令了。

二，TFTP下載菜單制作
1、在common文件夾下添加tftp_menu.c, 內(nèi)容如下：

#include <common.h>
#include <command.h>

static char awaitkey(unsigned long delay, int* error_p)
{
 int i;
 char c;
 if (delay == -1)
 {
  while (1)
  {
   if (tstc()) /* we got a key press */
   return getc();
  }
 }
 else
 {       
  for (i = 0; i < delay; i++)
  {
   if (tstc()) /* we got a key press */
   return getc();
   udelay (10*1000);
  }
 }
 if (error_p)
 *error_p = -1;
 
 return 0;
}

void main_menu_usage(void)
{
 printf("\r\n---u-boot-tftp-menu---\r\n");
 printf("[1] u-boot.bin --> Nand Flash\r\n");
 printf("[2] Linux(uImage) --> Nand Flash\r\n");
 printf("[3] yaffs2 --> Nand Flash\r\n");
 printf("[4] Linux(uImage) --> Ram & Run\r\n");
 printf("[5] System Restart\r\n");
 printf("[q] quite menu\r\n");
}

void menu_shell(void)
{
 char c;
 char cmd_buf[200];

 while (1)
 {
  main_menu_usage();
  c = awaitkey(-1, NULL);
  printf("%c\n", c);
  switch (c)
  {
   case '1':
   {
    strcpy(cmd_buf, "tftp 0x32000000 u-boot.bin; nand erase 0x0 0x40000; nand write 0x32000000 0x0 0x40000");
    run_command(cmd_buf, 0);
    break;
   }
   case '2':
   {
    strcpy(cmd_buf, "tftp 0x32000000 uImage; nand erase 0x200000 0x500000; nand write 0x32000000 0x200000 0x500000");
    run_command(cmd_buf, 0);
    break;
   }
   case '3':
   {
    strcpy(cmd_buf, "tftp 0x32000000 fs.yaffs2; nand erase 0x500000; nand write.yaffs2 0x32000000 0x500000 $(filesize)");
    run_command(cmd_buf, 0);
    break;
   }
   case '4':
   {
    strcpy(cmd_buf, "tftp 0x32000000 uImage; bootm 0x32000000");
    run_command(cmd_buf, 0);
    break;
   }
   case '5':
   {
    strcpy(cmd_buf, "reset");
    run_command(cmd_buf, 0);
    break;
   }
   case 'q':
   {
    return;   
    break;
   }
  }
 }
}

int do_menu (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
    menu_shell();
    return 0;
}

U_BOOT_CMD(
 tftp_menu, 1, 0, do_menu,
 "Download Menu",
 "U-boot Download Menu by Hotips\n"
);

2、修改common下同目錄cmd_menu.c的Makefile文件

vi common/Makefile 添加如下一行

COBJS-y += tftp_menu.o

3、make后下載到板子Nandflash 地址0處

啟動uboot進入控制臺后，輸入命令tftp_menu進入菜單如下

[SMDK2440]# tftp_menu

---u-boot-tftp-menu---

[1] u-boot.bin --> Nand Flash
[2] Linux(uImage) -->Nand Flash
[3] yaffs2 --> Nand Flash
[4] Linux(uImage) --> Ram & Run
[5] System Restart
[q] quite menu

三，支持Xmodem

1、在windows下的SecureCRT只支持Xmodem和Zmodem，為了方便在Windows下載U-Boot，現(xiàn)在修改代碼增加對Xmodem的支

持，即增加一個命令loadx。

vi common/cmd_load.c

在ymodem命令下添加xmodem命令

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'"
);

#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

上面的條件編譯需要在 include/configs/smdk2440.h中添加

#define ENABLE_CMD_LOADB_X     1

2、在do_load_serial_bin函數(shù)中增加對loadx命令的處理分支。也是依照loady來實現(xiàn)的：

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) {
  printf ("## Ready for binary (ymodem) download "
   "to 0x%08lX at %d bps...\n",
   offset,
   load_baudrate);

  addr = load_serial_ymodem (offset);

3、在第2步被調(diào)用的函數(shù)load_serial_xmodem (offset)，它是依照load_serial_ymodem (offset)實現(xiàn)的。添加在

ymodem函數(shù)的上面。

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 CONFIG_SYS_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;
}

注意：在文件頭部聲明一下static ulong load_serial_xmodem (ulong offset)函數(shù)。
#if defined(ENABLE_CMD_LOADB_X)
static ulong load_serial_xmodem (ulong offset)
#endif

至此，u-boot已經(jīng)支持串口xmodem協(xié)議。

用命令 loadx 即可

[SMDK2440]# loadx
## Ready for binary (xmodem) download to 0x32000000 at 115200 bps...
CCC

點擊SecureCRT菜單里Transfer選擇發(fā)送 Xmodem，選擇要下載的文件即可。