mtd----------嵌入式-------------------

 http://blog.sina.com.cn/s/blog_5d9051c00100ek1j.html

NAND是嵌入式系统一个很重要的部件，而mtd-utilts中包含了很多针对NAND的调试和测试的工具。
 
1. 在http://git.infradead.org/mtd-utils.git上下载最新的mtd-utils代码, 下面是以2009-07-03的代码为例。
2. 解压缩mtd-utils.tgz
3. cd mtd-utils,编辑common.mk: 增加CROSS=arm-linux-
4. 执行make即可。 
 
在mtd-utils中生成的主要工具有：
（1） flash_eraseall, 用于擦除指定的MTD分区， 用法如下：
      ./flash_eraseall /dev/mtd1     擦除MTD1
      ./flash_eraseall -j /dev/mtd1  擦除MTD1并将其格式化为JFFS2
（2）  nanddump,  打印（或保存）NAND中的内容，用法如下：
     ./nanddump -s 0 -l 8024 -f result.dat /dev/mtd1    将mtd1中从地址0开始的8024长度的内容保存到result.dat中，(缺省的，包含OOB的内容)
     注意，用vi或vim查看result.dat的内容时是2进制，在命令模式下，输入%!xxd即可转换为十六进制的可读内容。
（3）  其他的还有nandwrite, nandtest等。
 
 
在mtd-utils/ubi-utils中生成的工具是针对UBIFS的，包含：
（1）mtdinfo: 输出指定的mtd分区的信息, 该命令只对可读的设备分区有效。
用法： ./mtdinfo /dev/mtd1
 
（2）ubinfo:  输出指定的ubi设备的信息，不带参数时，输出系统所有的ubi设备以及ubi控制设备信息。ubi控制设备即/dev/ubi_ctrl是一个字符设备，在后面还将用到。
用法：./ubinfo
      ./ubinfo /dev/ubi0
 
（3）ubiformat:格式化指定的mtd分区, 参数使用的是mtd的字符设备
用法：./ubiformat /dev/mtd1
 
（4）ubiattach:将指定的mtd分区关联到ubi上
用法：./ubiattach /dev/ubi_ctrl -m 1， 将mtd1关连ubi
 
（5）ubidetach:解除mtd与ubi的关联
用法：./ubidetach /dev/ubi_ctrl -m 1
 
（6）ubimkvol:创建一个voluem，volume才是最终用户挂载文件系统的地方。
用法：在ubi2上创建4个olume，每个大小是20M, 名字分别为my_vol_a, my_vol_b, my_vol_c, my_vol_d.
./ubimkvol /dev/ubi2 -s 20Mib -N my_vol_a
./ubimkvol /dev/ubi2 -s 20Mib -N my_vol_b
./ubimkvol /dev/ubi2 -s 20Mib -N my_vol_c
./ubimkvol /dev/ubi2 -s 20Mib -N my_vol_d
 
（7）ubirename: 更改ubi某个olume的名字，或者完成两个volume的互换
用法：
（1）将ubi2上名字为my_vol_a的volume名字改为my_vol_newname
./ubirename /dev/ubi2 my_vol_a my_vol_newname
（2）将ubi2上名字为my_vol_b和my_vol_c的两个volume互换,
./ubirename /dev/ubi2 my_vol_b my_vol_c my_vol_c my_vol_b
 
（8）ubirmvol: 删除某个volume，可以通过名字或id指定具体的volume
用法： ./ubirmvol /dev/ubi2 -n 1
或./ubirmvol /dev/ubi2 -N my_vol_d
 
（9）ubinize: 创建ubi image。
用法: ./ubinize -o myubi.img -p 126976 -m 2048 my.ini
其中， -p, 指定的是目标flash的physical eraseblock的大小
       -s, 指定的是目标flash的minimum input/output unit 的大小， 这两个参数的值可以通过“cat /sys/class/ubi/ubi2/*”得到
       my.ini是配置文件，其中指定了原文件，目标volume的大小、名字等。其格式如小：
[jffs2-volume]
mode=ubi
image=../jffs2.img
vol_id=1
vol_size=30MiB
vol_type=dynamic
vol_name=jffs2_volume
vol_flags=autoresize
vol_alignment=1
（10）ubiupdatevol: 向指定的volume上写数据
用法：./ubiupdatevol /dev/ubi2_0 myubi.img
 

-------------------------------------------------------------------------------------------

  OKC6410使用---30让ubifs作rootfs  2013-08-23 12:29:35

分类： LINUX

                   by wangcong02345

                               欢迎转载,但请注明出处

                               http://blog.chinaunix.net/blog/post/id/3862627.html

一.mtd-utils编译过程
下载:
sun@ubuntu:/work/6410/tools$ git clone git://git.infradead.org/mtd-utils.git
修改Makefile
sun@ubuntu:/work/6410/tools/mtd-utils$ vi common.mk 
  1 CROSS=arm-none-linux-gnueabi-                               ;指定交叉编译器
 25 PREFIX=/tmp/mtd
1.第一次编译

 sun@ubuntu:/work/6410/tools/mtd-utils$ make
   CHK include/version.h
   LD ftl_format
   CC flash_erase.o
   LD flash_erase
   CC nanddump.o
   LD nanddump
   CC doc_loadbios.o
   LD doc_loadbios
   CC ftl_check.o
   LD ftl_check
   CC mkfs.jffs2.o
 mkfs.jffs2.c:70:21: error: sys/acl.h: No such file or directory
 mkfs.jffs2.c: In function 'formalize_posix_acl':
 mkfs.jffs2.c:1024: error: 'ACL_USER_OBJ' undeclared (first use in this function)
 mkfs.jffs2.c:1024: error: (Each undeclared identifier is reported only once
 mkfs.jffs2.c:1024: error: for each function it appears in.)
 mkfs.jffs2.c:1025: error: 'ACL_GROUP_OBJ' undeclared (first use in this function)
 mkfs.jffs2.c:1026: error: 'ACL_MASK' undeclared (first use in this function)
 mkfs.jffs2.c:1027: error: 'ACL_OTHER' undeclared (first use in this function)
 mkfs.jffs2.c:1033: error: 'ACL_USER' undeclared (first use in this function)
 mkfs.jffs2.c:1034: error: 'ACL_GROUP' undeclared (first use in this function)
 make: *** [/work/6410/tools/mtd-utils/arm-none-linux-gnueabi/mkfs.jffs2.o] Error 1

原因:  编译时调用acl.h了而没有调用zlib库
解决方法:指定WITHOUT_XATTR=1 指定编译时要调用zlib库

2.第二次编译

 sun@ubuntu:/work/6410/tools/mtd-utils$ make WITHOUT_XATTR=1
   CHK include/version.h
   CC mkfs.jffs2.o
   CC compr_rtime.o
   CC compr_zlib.o
   CC compr_lzo.o
 compr_lzo.c:31:23: error: lzo/lzo1x.h: No such file or directory
 compr_lzo.c: In function 'jffs2_lzo_cmpr':
 compr_lzo.c:53: error: 'lzo_uint' undeclared (first use in this function)
 compr_lzo.c:53: error: (Each undeclared identifier is reported only once
 compr_lzo.c:53: error: for each function it appears in.)
 compr_lzo.c:53: error: expected ';' before 'compress_size'
 compr_lzo.c:56: warning: implicit declaration of function 'lzo1x_999_compress'
 compr_lzo.c:56: error: 'compress_size' undeclared (first use in this function)
 compr_lzo.c:58: error: 'LZO_E_OK' undeclared (first use in this function)
 compr_lzo.c: In function 'jffs2_lzo_decompress':
 compr_lzo.c:74: error: 'lzo_uint' undeclared (first use in this function)
 compr_lzo.c:74: error: expected ';' before 'dl'
 compr_lzo.c:76: warning: implicit declaration of function 'lzo1x_decompress_safe'
 compr_lzo.c:76: error: 'dl' undeclared (first use in this function)
 compr_lzo.c:78: error: 'LZO_E_OK' undeclared (first use in this function)
 compr_lzo.c: In function 'jffs2_lzo_init':
 compr_lzo.c:97: error: 'LZO1X_999_MEM_COMPRESS' undeclared (first use in this function)
 make: *** [/work/6410/tools/mtd-utils/arm-none-linux-gnueabi/compr_lzo.o] Error 1

原因: 没有lzo库
解决方法:编译lzo库,并添加到交叉编译工具链中

 sun@ubuntu:/work/6410/tools/mtd-utils$ cd ..
 sun@ubuntu:/work/6410/tools$ wget http://www.oberhumer.com/opensource/lzo/download/lzo-2.06.tar.gz   //下载lzo库
 sun@ubuntu:/work/6410/tools$ ls
 lzo-2.06.tar.gz mtd-utils
 //下面的config指定交叉编译器
 sun@ubuntu:/work/6410/tools/lzo-2.06$ CC=arm-none-linux-gnueabi-gcc ./configure --host=arm-linux --prefix=/opt/6410/4.3.2/arm-none-linux-gnueabi/
 //编译
 sun@ubuntu:/work/6410/tools/lzo-2.06$ make && make install
 //确认在工具链目录中是否己经有头文件了
 sun@ubuntu:/work/6410/tools/lzo-2.06$ find /opt/6410/4.3.2/ -name "lzo1x.h"
 /opt/6410/4.3.2/arm-none-linux-gnueabi/include/lzo/lzo1x.h

3.第三次编译

 sun@ubuntu:/work/6410/tools/mtd-utils$ make WITHOUT_XATTR=1
   CHK include/version.h
   LD mkfs.jffs2
 /opt/6410/4.3.2/bin/../lib/gcc/arm-none-linux-gnueabi/4.3.2/../../../../arm-none-linux-gnueabi/bin/ld: cannot find -lz
 collect2: ld returned 1 exit status
 make: *** [/work/6410/tools/mtd-utils/arm-none-linux-gnueabi/mkfs.jffs2] Error 1

原因: 没有libz库
解决方法:编译libz库,并添加到交叉编译工具链中

 sun@ubuntu:/work/6410/tools$ wget http://zlib.net/zlib-1.2.8.tar.gz   //下载lzo库
 sun@ubuntu:/work/6410/tools$ ls
 lzo-2.06 lzo-2.06.tar.gz lzo-2.06.tar.gz.1 mtd-utils zlib-1.2.8.tar.gz
 sun@ubuntu:/work/6410/tools$ tar xf zlib-1.2.8.tar.gz
 sun@ubuntu:/work/6410/tools$ cd zlib-1.2.8/
 //下面的config指定交叉编译器
 sun@ubuntu:/work/6410/tools/zlib-1.2.8$ CC=arm-none-linux-gnueabi-gcc ./configure --shared --prefix=/opt/6410/4.3.2/arm-none-linux-gnueabi/
 //编译并安装到工具链目录中
 sun@ubuntu:/work/6410/tools/zlib-1.2.8$ make && make install
 //确认在工具链目录中是否己经有库了
 sun@ubuntu:/work/6410/tools/zlib-1.2.8$ find /opt/6410/4.3.2/arm-none-linux-gnueabi/ -name "libz*"
 /opt/6410/4.3.2/arm-none-linux-gnueabi/lib/libz.a
 /opt/6410/4.3.2/arm-none-linux-gnueabi/lib/libz.so.1
 /opt/6410/4.3.2/arm-none-linux-gnueabi/lib/libz.so.1.2.8
 /opt/6410/4.3.2/arm-none-linux-gnueabi/lib/libz.so
 /opt/6410/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib/libz.a

4.第四次编译

 sun@ubuntu:/work/6410/tools/mtd-utils$ make WITHOUT_XATTR=1
 In file included from mkfs.ubifs/mkfs.ubifs.c:26:
 mkfs.ubifs/mkfs.ubifs.h:46:23: error: uuid/uuid.h: No such file or directory
 mkfs.ubifs/mkfs.ubifs.c: In function 'write_data':
 mkfs.ubifs/mkfs.ubifs.c:1621: warning: implicit declaration of function 'time'
 mkfs.ubifs/mkfs.ubifs.c: In function 'write_super':
 mkfs.ubifs/mkfs.ubifs.c:1934: warning: implicit declaration of function 'uuid_generate_random'
 mkfs.ubifs/mkfs.ubifs.c:1938: warning: implicit declaration of function 'uuid_unparse_upper'
 make: *** [/work/6410/tools/mtd-utils/arm-none-linux-gnueabi/mkfs.ubifs/mkfs.ubifs.o] Error 1

原因: 找不到头文件uuid
解决方法:

 sun@ubuntu:/opt/6410/4.3.2$ grep "uuid_generate_random" * -R
       arm-none-linux-gnueabi/libc/usr/include/uuid.h:void uuid_generate_random(uuid_t out);
 //搜索发现uuid.h是在include目录下而不是在uuid这个目录下,所以只需要改一下路径就可以了
 sun@ubuntu:/work/6410/tools/mtd-utils$ vi mkfs.ubifs/mkfs.ubifs.h
  46 //#include <uuid/uuid.h>
  47 #include <uuid.h>

5.第五次编译

 sun@ubuntu:/work/6410/tools/mtd-utils$ make WITHOUT_XATTR=1
   CHK include/version.h
   CC mkfs.ubifs/mkfs.ubifs.o
   CC mkfs.ubifs/crc16.o
   CC mkfs.ubifs/lpt.o
   CC mkfs.ubifs/compr.o
   CC mkfs.ubifs/devtable.o
   CC mkfs.ubifs/hashtable/hashtable.o
   CC mkfs.ubifs/hashtable/hashtable_itr.o
   CC ubi-utils/libubi.o
   AR ubi-utils/libubi.a
   LD mkfs.ubifs/mkfs.ubifs
 /opt/6410/4.3.2/bin/../lib/gcc/arm-none-linux-gnueabi/4.3.2/../../../../arm-none-linux-gnueabi/bin/ld: cannot find -luuid
 collect2: ld returned 1 exit status

原因: 找不到库libuuid
解决方法:

 sun@ubuntu:/opt/6410/4.3.2$ find . -name "libuuid*"
 ./arm-none-linux-gnueabi/libc/armv4t/usr/lib/libuuid.so.1
 ./arm-none-linux-gnueabi/libc/armv4t/usr/lib/libuuid.so
 ./arm-none-linux-gnueabi/libc/armv4t/usr/lib/libuuid.so.1.2
 //搜索发现libuuid是在libc/armv4t/usr/lib目录下,arm-none-linux-gnueabi-ld找不到,所以加个软链接
 sun@ubuntu:/opt/6410/4.3.2/arm-none-linux-gnueabi/lib$ ln -s ../libc/armv4t/usr/lib/libuuid.so ./libuuid.so

6.第六次编译
OK,可以了,这样就有了一大串命令

 sun@ubuntu:/work/6410/tools/mtd-utils$ ls /tmp/mtd/sbin/
 docfdisk flash_eraseall flash_otp_lock ftl_format mkfs.ubifs nandtest recv_image sumtool ubiformat ubirename
 doc_loadbios flash_lock flash_otp_write jffs2dump mtd_debug nandwrite rfddump ubiattach ubimkvol ubirmvol
 flashcp flash_otp_dump flash_unlock jffs2reader mtdinfo nftldump rfdformat ubicrc32 ubinfo ubirsvol
 flash_erase flash_otp_info ftl_check mkfs.jffs2 nanddump nftl_format serve_image ubidetach ubinize ubiupdatevol

二. linux中ubifs的使用
在 NFS 启动系统 时 将编译好的mtd-util复制到nfs系统中的/sbin/目录
1. 重新编译内核添加ubi与ubifs的支持

 Device Drivers --->
  <*> Memory Technology Device (MTD) support --->
      <*> Enable UBI - Unsorted block images --->

 File systems --->
  [*] Miscellaneous filesystems --->
      <*> UBIFS file system support

2. 查看分区信息

 root@OK6410:~# mtdinfo -u
 Count of MTD devices: 3
 Present MTD devices: mtd0, mtd1, mtd2
 Sysfs interface supported: yes

或者

 root@OK6410:~# cat /proc/mtd
 dev: size erasesize name
 mtd0: 00100000 00080000 "Bootloader"
 mtd1: 00500000 00080000 "Kernel"
 mtd2: 7fa00000 00080000 "File System"
 root@OK6410:~# mtdinfo /dev/mtd0
 mtd0
 Name: Bootloader
 Type: nand
 Eraseblock size: 524288 bytes, 512.0 KiB
 Amount of eraseblocks: 2 (1048576 bytes, 1024.0 KiB)
 Minimum input/output unit size: 4096 bytes
 Sub-page size: 4096 bytes
 OOB size: 218 bytes
 Character device major/minor: 90:0
 Bad blocks are allowed: true
 Device is writable: false

3. 将文件系统格式化为ubifs
ubiformat: a tool to format MTD devices and flash UBI images

 root@OK6410:~# ubiformat /dev/mtd2
 ubiformat: mtd2 (nand), size 2141192192 bytes (2.0 GiB), 4084 eraseblocks of 524288 bytes (512.0 KiB), min. I/O size 4096 bytes
 libscan: scanning eraseblock 4083 -- 100 % complete
 ubiformat: 4070 eraseblocks are supposedly empty
 ubiformat: 2 bad eraseblocks found, numbers: 3, 121
 ubiformat: 12 of 4082 eraseblocks contain non-ubifs data
 ubiformat: continue? (y/N) y
 ubiformat: only 0 of 4082 eraseblocks have valid erase counter
 ubiformat: erase counter 0 will be used for all eraseblocks
 ubiformat: note, arbitrary erase counter value may be specified using -e option
 ubiformat: continue? (y/N) y
 ubiformat: use erase counter 0 for all eraseblocks
 ubiformat: formatting eraseblock 4083 -- 100 % complete

4. 将文件系统与ubi_ctrl相关联

 root@OK6410:~# ubiattach /dev/ubi_ctrl -m 2
 UBI: attaching mtd2 to ubi0
 UBI: physical eraseblock size: 524288 bytes (512 KiB)
 UBI: logical eraseblock size: 516096 bytes
 UBI: smallest flash I/O unit: 4096
 UBI: VID header offset: 4096 (aligned 4096)
 UBI: data offset: 8192
 UBI: max. sequence number: 0
 UBI: attached mtd2 to ubi0
 UBI: MTD device name: "File System"
 UBI: MTD device size: 2042 MiB
 UBI: number of good PEBs: 4082
 UBI: number of bad PEBs: 2
 UBI: number of corrupted PEBs: 0
 UBI: max. allowed volumes: 128
 UBI: wear-leveling threshold: 4096
 UBI: number of internal volumes: 1
 UBI: number of user volumes: 0
 UBI: available PEBs: 4038
 UBI: total number of reserved PEBs: 44
 UBI: number of PEBs reserved for bad PEB handling: 40
 UBI: max/mean erase counter: 0/0
 UBI: image sequence number: 557638241
 UBI: background thread "ubi_bgt0d" started, PID 96
 UBI device number 0, total 4082 LEBs (2106703872 bytes, 2.0 GiB), available 4038 LEBs (2083995648 bytes, 1.9 GiB), LEB size 516096 bytes (504.0 KiB)

查看ubi信息

 root@OK6410:~# ubinfo -a
 UBI version: 1
 Count of UBI devices: 1
 UBI control device major/minor: 10:63
 Present UBI devices: ubi0
 ubi0
 Volumes count: 0
 Logical eraseblock size: 516096 bytes, 504.0 KiB
 Total amount of logical eraseblocks: 4082 (2106703872 bytes, 2.0 GiB)
 Amount of available logical eraseblocks: 4038 (2083995648 bytes, 1.9 GiB)
 Maximum count of volumes 128
 Count of bad physical eraseblocks: 2
 Count of reserved physical eraseblocks: 40
 Current maximum erase counter value: 0
 Minimum input/output unit size: 4096 bytes
 Character device major/minor: 252:0

5. 创建volume

 root@OK6410:~# ubimkvol /dev/ubi0 -N ubifs -m
 Set volume size to 2083995648
 Volume ID 0, size 4038 LEBs (2083995648 bytes, 1.9 GiB), LEB size 516096 bytes (504.0 KiB), dynamic, name "ubifs", alignment 1
 root@OK6410:~# ubinfo -a
 UBI version: 1
 Count of UBI devices: 1
 UBI control device major/minor: 10:63
 Present UBI devices: ubi0
 ubi0
 Volumes count: 1
 Logical eraseblock size: 516096 bytes, 504.0 KiB
 Total amount of logical eraseblocks: 4082 (2106703872 bytes, 2.0 GiB)
 Amount of available logical eraseblocks: 0 (0 bytes)
 Maximum count of volumes 128
 Count of bad physical eraseblocks: 2
 Count of reserved physical eraseblocks: 40
 Current maximum erase counter value: 1
 Minimum input/output unit size: 4096 bytes
 Character device major/minor: 252:0
 Present volumes: 0
 Volume ID: 0 (on ubi0)
 Type: dynamic
 Alignment: 1
 Size: 4038 LEBs (2083995648 bytes, 1.9 GiB)
 State: OK
 Name: ubifs
 Character device major/minor: 252:1
 root@OK6410:~# mount -t ubifs ubi0_0 /mnt/ubi/
 UBIFS: default file-system created
 UBIFS: mounted UBI device 0, volume 0, name "ubifs"
 UBIFS: file system size: 2078834688 bytes (2030112 KiB, 1982 MiB, 4028 LEBs)
 UBIFS: journal size: 33546240 bytes (32760 KiB, 31 MiB, 65 LEBs)
 UBIFS: media format: w4/r0 (latest is w4/r0)
 UBIFS: default compressor: lzo
 UBIFS: reserved for root: 4952683 bytes (4836 KiB)

6. 挂载ubifs

 //创建挂载目录
 root@OK6410:~# mkdir -p /mnt/ubi
 //挂载
 root@OK6410:~# mount -t ubifs ubi0_0 /mnt/ubi/
 UBIFS: default file-system created
 UBIFS: mounted UBI device 0, volume 0, name "ubifs"
 UBIFS: file system size: 2078834688 bytes (2030112 KiB, 1982 MiB, 4028 LEBs)
 UBIFS: journal size: 33546240 bytes (32760 KiB, 31 MiB, 65 LEBs)
 UBIFS: media format: w4/r0 (latest is w4/r0)
 UBIFS: default compressor: lzo
 UBIFS: reserved for root: 4952683 bytes (4836 KiB)

 //查看
 root@OK6410:~# df -h
 Filesystem Size Used Available Use% Mounted on
 192.168.6.220:/work/6410/yaffs2/
                         147.6G 93.4G 46.8G 67% /
 tmpfs 37.8M 0 37.8M 0% /dev/shm
 ubi0_0 1.8G 28.0K 1.8G 0% /mnt/ubi

三. 在PC上制作ubifs镜像
1. 编译mtd-util的pc版
需要先安装uuid-dev,要不会报以下错误:

 sun@ubuntu:/work/6410/pctools/mtd-utils$ make WITHOUT_XATTR=1
 In file included from mkfs.ubifs/mkfs.ubifs.c:26:0:
 mkfs.ubifs/mkfs.ubifs.h:47:18: fatal error: uuid.h: No such file or directory
 compilation terminated.
 make: *** [/work/6410/pctools/mtd-utils/mkfs.ubifs/mkfs.ubifs.o] Error 1

 sun@ubuntu:/work/6410/pctools/mtd-utils$ sudo apt-get install uuid-dev

2.在PC机上制作ubi的镜像

 sun@ubuntu:/work/6410/test$ sudo /tmp/mtdpc/sbin/mkfs.ubifs -r rootfs -m 4096 -e 516096 -c 4038 -o ubifs.img
 sun@ubuntu:/work/6410/test$ sudo /tmp/mtdpc/sbin/ubinize -o ubi.img -m 4096 -s 4096 -p 512KiB ubifs.conf

参数解析:
-r：制定文件内容的位置                    /work/6410/test/rootfs 目录下
-m：页面大小                                 4096
-e：逻辑擦除块大小                         516096:Logical eraseblock size: 516096 bytes--> ubinfo -a
-p：物理擦除块大小                         512K, 这个参数是datasheet中一个block的大小
-c：最大的逻辑擦除块数量                4038:  Amount of available logical eraseblocks --> ubinfo -a
-s：最小的硬件输入输出页面大小，    Minimum input/output unit size: 4096 bytes

四. 在6410上烧写ubifs镜像,并启动
1. 在6410中将ubi.img写入到nand flash上去
a.查看文件系统的路径,注意这儿是nfs启动的

 root@OK6410:~# cat /proc/mtd
 dev: size erasesize name
 mtd0: 00100000 00080000 "Bootloader"
 mtd1: 00500000 00080000 "Kernel"
 mtd2: 7fa00000 00080000 "File System"

b.格式化为ubifs
从上面可以看出mtd2是nand flash的文件系统,所以要将mtd2格式化成ubifs

 root@OK6410:/work# ubiformat /dev/mtd2 -s 4096 -f /work/ubi.img

这儿用到了ubiformat的-f指令:把ubifs的镜像文件/work/ubi.img烧到/dev/mtd2中
c.下面检查一下是否挂载成功

   root@OK6410 : / work# ubiattach  / dev / ubi_ctrl  - m 2

 root@OK6410:/work# mount -t ubifs ubi0:ubifs /mnt/ubi/
 UBIFS: mounted UBI device 0, volume 0, name "ubifs"
 UBIFS: file system size: 2078834688 bytes (2030112 KiB, 1982 MiB, 4028 LEBs)
 UBIFS: journal size: 10452992 bytes (10208 KiB, 9 MiB, 21 LEBs)
 UBIFS: media format: w4/r0 (latest is w4/r0)
 UBIFS: default compressor: lzo
 UBIFS: reserved for root: 0 bytes (0 KiB)

特别注意: ubi0 : ubifs 中后面这个ubifs是分区name,可以在ubimkvol中设定,我这儿设定的name=ubifs 
ubimkvol /dev/ubi0 -N ubifs -m
d. 设定u-boot中的bootargs

 setenv bootargs "console=ttySAC0,115200 ubi.mtd=2 root=ubi0:ubifs rootfstype=ubifs"

注意:  我试过下面这个就是多加了init=linuxrc

 setenv bootargs "console=ttySAC0,115200 ubi.mtd=2 root=ubi0:ubifs rootfstype=ubifs init=/linuxrc"

但是出现下面这个错误,所以不用加init=/linuxrc

 VFS: Unable to mount root fs via NFS, trying floppy.
 Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)
 [<c003acac>] (unwind_backtrace+0x0/0xfc) from [<c0494430>] (dump_stack+0x18/0x1c)
 [<c0494430>] (dump_stack+0x18/0x1c) from [<c0494494>] (panic+0x60/0x1ac)
 [<c0494494>] (panic+0x60/0x1ac) from [<c0008fb4>] (mount_block_root+0x1bc/0x25c)
 [<c0008fb4>] (mount_block_root+0x1bc/0x25c) from [<c00090dc>] (mount_root+0x88/0xd0)
 [<c00090dc>] (mount_root+0x88/0xd0) from [<c0009230>] (prepare_namespace+0x10c/0x1a8)
 [<c0009230>] (prepare_namespace+0x10c/0x1a8) from [<c00084c4>] (kernel_init+0xf0/0x130)
 [<c00084c4>] (kernel_init+0xf0/0x130) from [<c0035a34>] (kernel_thread_exit+0x0/0x8

下面是成功的mount

 root@OK6410:~# mount
 rootfs on / type rootfs (rw)
 ubi0:ubifs on / type ubifs (rw,relatime)