yaffs2文件系统制作 .

 

【环境】

1：Ubuntu 10.10

2：u-boot-2010.03

3：优龙FS2410

4：交叉编译器:arm-none-linux-gnueabi-gcc version 4.3.2

第一步：在内核里添加yaffs2的支持

1）下载源码

tony@Ubuntu:~/ win$ sudo apt-get install git
tony@Ubuntu:~/ win$ git clone git://www.aleph1.co.uk/yaffs2 

2）给内核打补丁 

tony@Ubuntu:~/win/yaffs2$./patch-ker.sh c m /home/tony/win/linux-2.6.35      // 这里是内核源码路径 

3）配置内核 （1：没有打过补丁的内核  2：已设置好交叉编译器）

tony@Ubuntu:~/win/linux-2.6.35$ make menuconfig 
File systems  ---> 

[*] Miscellaneous filesystems  ---> 

<*>   YAFFS2 file system support 

-*-     512 byte / page devices

[*]    Lets yaffs do its own ECC 

-*-     2048 byte (or larger) / page devices 

[*]    Autoselect yaffs2 format 

[*]    Enable yaffs2 xattr support 

4）禁用内核NandFlash的ECC校样

tony@Ubuntu:~/win/linux-2.6.35$vim drivers/mtd/nand/s3c2410.c

842行：

修改：chip->eccmode = NAND_ECC_SOFT;

改为：chip->eccmode = NAND_ECC_NONE;

5）重新编译内核 
tony@Ubuntu:~/win/linux-2.6.35$ make uImage 

6）拷贝内核到TFTP目录 
tony@Ubuntu:~/win/linux-2.6.35$ cp arch/arm/boot/uImage /tftpboot 

7）重新启动开发板 
# cat /proc/filesystems  
 nodev sysfs

 nodev rootfs 

 nodev bdev 

 nodev proc 

 nodev tmpfs 

 nodev sockfs 

 nodev usbfs 

 nodev pipefs 

 nodev anon_inodefs 

 nodev rpc_pipefs 

 nodev devpts 

ext3 

ext2 

cramfs 

 nodev ramfs 

vfat 

msdos 

iso9660 

nodev nfs 
nodev jffs2 

romfs 

yaffs 

yaffs2 

nodev mtd_inodefs 

第二步：实现u-boot对Yaffs2文件系统的支持

①、在include/configs/smdk2440.h头文件中定义一个管理对Yaffs2支持的宏和开启u-boot中对Nand Flash默认分区的宏

tony@Ubuntu:~/win/u-boot-2010.03$vim include/configs/fs2410.h

#define CONFIG_MTD_NAND_YAFFS2   1 //定义一个管理对Yaffs2支持的宏

//开启Nand Flash默认分区，注意此处的分区要和你的内核中的分区保持一致

#define MTDIDS_DEFAULT "nand0=nandflash0"

#define MTDPARTS_DEFAULT "mtdparts=nandflash0:1m(bootloader u-boot-2010.03)," \

                     "4m(kernel linux-2.6.35)," \

                     "8m(rootfs busybox-1.17.3)," \

                     "-(usrfs)"

②、在common/cmd_nand.c中，对Nand操作的命令集列表中添加Yaffs2对Nand的写命令（在U_BOOT_CMD中添加）

tony@Ubuntu:~/win/u-boot-2010.03$vim common/cmd_nand.c

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：这里只添加了yaffs2的写命令，因为我们只用u-boot下载(即写)功能，所以我们没有添加yaffs2读的命令
#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
);

接着，在该文件中对nand操作的do_nand函数中添加yaffs2对nand的操作

    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相关操作，注意该处又关联到nand_write_skip_bad函数

#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;
    }

③、在include/linux/mtd/mtd.h头文件的mtd_info结构体中添加上面用到rw_oob和skipfirstblk数据成员

tony@Ubuntu:~/win/u-boot-2010.03$vim include/linux/mtd/mtd.h

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

④、在第二步关联的drivers/mtd/nand/nand_util.c 的nand_write_skip_bad函数中添加对Nand OOB的相关操作

tony@Ubuntu:~/win/u-boot-2010.03$vim drivers/mtd/nand/nand_util.c

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

#if 0

    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;
        //offset        += write_size;
        //p_buffer      += write_size;

        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;
}

⑤、在第四步nand_write_skip_bad函数中我们看到又对nand_write函数进行了访问，所以这一步是到drivers/mtd/nand/nand_base.c  的nand_write函数中添加对yaffs2的支持

tony@Ubuntu:~/win/u-boot-2010.03$vim drivers/mtd/nand/nand_base.c

2095行

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;
    //chip->ops.oobbuf = NULL;

#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，对yaffs2支持的代码已修改完毕，重新编译u-boot并下载到nand中，启动开发板，在u-boot的命令行输入:nand help查看nand的命令，可以看到多了一个nand write[.yaffs2]的命令，这个就是用来下载yaffs2文件系统到nand中的命令了。

第三步：用busybox制作yaffs2根文件系统

1）参看--》根文件系统制作

2）目标板NandFlash是64MB的，所以要使用mkyaffs2image_2这个版本的可执行文件来生成映像

tony@Ubuntu:/opt$ mkyaffsimage_2 filesystem filesystem.yaffs2

tony@Ubuntu:/opt$cp filesystem.yaffs2 /tftpboot/

3）烧录到NandFlash中并测试

tftp 30008000 filesystem.yaffs2

nand erase 500000 800000

nand write.yaffs2 30008000 500000 实际大小

setenv bootargs root=/dev/mtdblock2 init=/linuxrc rootfstype=yaffs2 rw console=ttySAC0,115200