码迷,mamicode.com
首页 > 其他好文 > 详细

使用ubifs格式的根文件系统

时间:2017-09-21 15:45:34      阅读:336      评论:0      收藏:0      [点我收藏+]

标签:ace   name   date   dynamic   mic   systems   log   文件   write   

  • 配置内核,使其支持ubifs文件系统

    1)Device Drivers  --->Memory Technology Device (MTD) support  --->UBI - Unsorted block images  --->Enable UBI     2)File systems  --->Miscellaneous filesystems  --->UBIFS file system support

  • 制作ubifs格式的根文件系统镜像

先说明一下,板子上既有NorFlash,又有NandFlash,其中根文件系统和应用程序放在NandFlash上,uboot和kernel放在NorFlash上,而根文件系统所在的mtd设备为mtd2,分区大小为34MiB

uboot kernel rootfs=34MiB app

 

  • ./mkfs.ubifs -v -r ./rootfs -o rootfs.img -m 2048 -e 129024 -c 272

   -r:制定文件内容的位置      -m:页面大小      -e:逻辑擦除块大小      -c:最大的逻辑擦除块数量

 

mkfs.ubifs -m 2048 -e 129024 -c 1984 -o rootfs.ubifs -x none

-m 2048   (Minimum input/output unit size: 2048 bytes)
-e 129024 (Default UBI LEB size:           129024 bytes, 126.0 KiB)
-c 1984   (Amount of eraseblocks:          1984 (260046848 bytes, 248.0 MiB))
-o rootfs.ubifs (output file)
-x none   (no compression)

 

 

  • ./ubinize -v -o rootfs.ubi -m 2048 -p 128KiB -s 2048 hi.cfg

     -p:物理擦除块大小 

     -m:页面大小

      -s: 最小的硬件输入输出页面大小,如:k9f1208为256(上下半页访问)

配置文件hi.cfg如下:

 

[ubifs] mode=ubi image=rootfs.img vol_id=0 vol_size=34MiB vol_type=dynamic vol_alignment=1 vol_name=rootfs vol_flag=autoresize

 

 然后修改uboot的环境变量:

setenv bootargs ‘mem=288M console=ttyAMA0,115200 root=ubi0:rootfs rw rootflags=sync rootfstype=ubifs ubi.mtd=2 mtdparts=hi_sfc:5M(boot),1M(picture);hinand:34M(rootfs),8M(config),86M(app)‘;

保存环境变量,执行如下命令

 

setenv ipaddr 192.168.253.132;

setenv serverip 192.168.253.130;

setenv ethaddr 40:61:86:67:33:47;

mw.b 82000000 ff 2200000;

tftp 82000000 rootfs.ubi;

nand erase 0 2200000;

nand write 82000000 0 $(filesize);

sf probe 0;

sf read 0x82000000 0x100000 0x400000;

bootm 0x82000000

 

说明:

其实从上面的烧写命令可以看出,ubifs格式的镜像中是不包含oob信息的。 

参见:http://www.cnblogs.com/pengdonglin137/p/3399071.html

 

出现如下错误信息:

 

UBI: attaching mtd2 to ubi0 UBI: physical eraseblock size: 131072 bytes (128 KiB) UBI: logical eraseblock size: 126976 bytes UBI: smallest flash I/O unit: 2048 UBI: VID header offset: 2048 (aligned 2048) UBI: data offset: 4096 UBI: max. sequence number: 0 UBI error: vtbl_check: volume table check failed: record 0, error 9 UBI error: ubi_init: cannot attach mtd2 Fixed MDIO Bus: probed

 

原因:

参考     http://wiki.linpert.de/index.php?title=UBIFS#record_0.2C_error_9  

             http://lists.infradead.org/pipermail/linux-mtd/2009-April/025127.html

 

But I took a look into the code, and the following is error 9:

                if (reserved_pebs > ubi->good_peb_count) {
                        dbg_err("too large reserved_pebs %d, good PEBs %d",
                                reserved_pebs, ubi->good_peb_count);
                        err = 9;
                        goto bad;
                }

This means you created a too large UBI volume in the image,
and your real flash is smaller.

Try to enable UBI debugging, and type dmesg, then you‘ll see
reserved and real eraseblock numbers.

原因就是:在配置文件中,volume设为34MiB,太大了,因为整个mtd2分区总共才34MiB。

解决办法:将配置文件改为:

[ubifs] mode=ubi image=rootfs.img vol_id=0 vol_size=32MiB vol_type=dynamic vol_alignment=1 vol_name=rootfs vol_flag=autoresize

说明:

vol_id  表示volume的编号,一个ubi设备中可以有多个volume。(这种情况下,/dev下会出现 ubi0 和 ubi0_0)

vol_size 表示ubi0_0的大小,即volume0的大小

vol_type 表示volume0的类型,分为dynamic和static两种,其中dynamic类型的设备表示可以读写,static类型的设备表示只读

vol_name 表示volume0的名称,在挂载ubi分区是会使用到,如在bootargs中的root=ubi0:rootfs

然后重新执行:   ./ubinize -v -o rootfs.ubi -m 2048 -p 128KiB -s 2048 hi.cfg

 

当再次重启后,又出现如下错误信息:

 

UBIFS: parse sync UBIFS error (pid 1): validate_sb: LEB size mismatch: 129024 in superblock, 126976 real UBIFS error (pid 1): validate_sb: bad superblock, error 1

 

原因:

参考:http://www.linux-mtd.infradead.org/faq/ubifs.html#L_lebsz_mismatch

 

I see this UBIFS error: "validate_sb: LEB size mismatch: 129024 in superblock, 126976 real"

 

When you create an UBIFS image using the mkfs.ubifs utility, you specify LEB size using the -e option. This is a very important parameter and you should specify it correctly in order to have working UBIFS image. Indeed, LEB size is the major UBIFS storage unit, e.g., UBIFS nodes never cross LEB boundaries, garbage collection is performed on individual LEBs, etc. See this section for more information.

 

The error message means that LEB size information which is stored in the UBIFS superblock does not match the real LEB size, which UBIFS takes from UBI. The superblock was created by the mkfs.ubifs utility, therefore you failed to pass the correct LEB size to the utility. Fix this by passing correct LEB size via the -e option.

 

原因是:逻辑块的大小与实际的大小不符

解决办法:

将-e选项的值由129024改成126976

重新执行:

 ./mkfs.ubifs -v -r ./rootfs -o rootfs.img -m 2048 -e 126976 -c 272

 ./ubinize -v -o rootfs.ubi -m 2048 -p 128KiB -s 2048 hi.cfg

重新烧写并重启。

还有一个需要注意的问题是,如果将-s选项的值搞错,如将2048写成了512,那么会有如下错误信息

UBI error: validate_ec_hdr: bad VID header offset 512, expected 2048 UBI error: validate_ec_hdr: bad EC header UBI error: ubi_io_read_ec_hdr: validation failed for PEB 0 UBI error: ubi_init: cannot attach mtd2 Fixed MDIO Bus: probed

从错误提示中就可以看到解决方法:将-s选项的值改为2048即可。

参考:http://www.cnblogs.com/pengdonglin137/p/3404685.html

 UBI headers

UBI stores 2 small 64-byte headers at the beginning of each non-bad physical eraseblock:

  • erase counter header (or EC header) which contains the erase counter of the physical eraseblock (PEB) plus some other not so important information;
  • volume identifier header (or VID header) which stores volume ID and logical eraseblock (LEB) number this PEB belongs to (plus some other not so important information).

This is why logical eraseblocks are smaller than physical eraseblock - the headers take some flash space.

 

UBI headers position

The EC header always resides at offset 0 and takes 64 bytes, the VID header resides at the next available min. I/O unit or sub-page, and also takes 64 bytes. For example:

  • in case of NOR flash which has 1 byte min. I/O unit, the VID header resides at offset 64;
  • in case of NAND flash which does not have sub-pages, the VID header resides at the second NAND page;
  • in case of NAND flash which has sub-pages, the VID header resides at the second sub-page.

 

UBI utilizes sub-pages to lessen flash space overhead. The overhead is less if NAND flash supports sub-pages (see here). Indeed, let‘s consider a NAND flash with 128KiB eraseblocks and 2048-byte pages. If it does not have sub-pages, UBI puts the the VID header at physical offset 2048, so LEB size becomes 124KiB (128KiB minus one NAND page which stores the EC header and minus another NAND page which stores the VID header. In opposite, if the NAND flash does have sub-pages, UBI puts the VID header at physical offset 512 (the second sub-page), so LEB size becomes 126KiB (128KiB minus one NAND page which is used for storing both UBI headers). See this section for more information about where the UBI headers are stored.

 

也就是说,对于上面的例子,如果有subpage(可以到/sys/class/mtd/其中的一个目录下使用cat命令去查看某个mtd设备的subpagesize参数),如果是512B,这有如下参数搭配(对于块大小是128KiB,页大小是2KB的NandFlash来说):

 ./mkfs.ubifs -v -r ./rootfs -o rootfs.img -m 2048 -e 129024 -c 272 

 ./ubinize -v -o rootfs.ubi -m 2048 -p 128KiB -s 512 hi.cfg

 

 其中 -e表示的是逻辑块的大小,因为subpagesize大小是512(也就是-s选项的值),第一页的前512存放EC(实际用了前64B),接下来的512B(前64B)存放UBI headers,逻辑块的大小就是128KiB-2KiB=126KiB,转化成十进制就是129024。

 假如没有subpagesize,那么有如下搭配:

 ./mkfs.ubifs -v -r ./rootfs -o rootfs.img -m 2048 -e 126976 -c 272 

 ./ubinize -v -o rootfs.ubi -m 2048 -p 128KiB -s 2048 hi.cfg

 其中,逻辑块的大小:128KiB-2KiB-2KiB=124KiB,转换成10进制就是126976,-s后面的值为页大小,即2048B。

使用ubifs格式的根文件系统

标签:ace   name   date   dynamic   mic   systems   log   文件   write   

原文地址:http://www.cnblogs.com/zxc2man/p/7568731.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!