最近由于工作需求，想做一个ubifs文件系统，但是挂载失败，请大侠帮忙分析一下，错误信息如下：
UBI: attaching mtd2 to ubi0
UBI: physical eraseblock size: 131072 bytes (128 KiB)
UBI: logical eraseblock size: 129024 bytes
UBI: smallest flash I/O unit: 2048
UBI: sub-page size: 512
UBI: VID header offset: 512 (aligned 512)
UBI: data offset: 2048
UBI: attached mtd2 to ubi0
UBI: MTD device name: "nand.rootfs"
UBI: MTD device size: 235 MiB
UBI: number of good PEBs: 1873
UBI: number of bad PEBs: 7
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: 1851
UBI: total number of reserved PEBs: 22
UBI: number of PEBs reserved for bad PEB handling: 18
UBI: max/mean erase counter: 2/1
UBI: image sequence number: 0
UBI: background thread "ubi_bgt0d" started, PID 337
UBIFS error (pid 1): ubifs_get_sb: cannot open "ubi0:rootfs", error -19
VFS: Cannot open root device "ubi0:rootfs" or unknown-block(0,0)
Please append a correct "root=" boot option; here are the available partitions:
1f00 16384 mtdblock0 (driver?)
1f01 5120 mtdblock1 (driver?)
1f02 240640 mtdblock2 (driver?)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[<8002a128>] (unwind_backtrace+0x0/0xe0) from [<8030fb8c>] (panic+0x68/0xdc)
[<8030fb8c>] (panic+0x68/0xdc) from [<80008d58>] (mount_block_root+0x234/0x284)
[<80008d58>] (mount_block_root+0x234/0x284) from [<80008e8c>] (prepare_namespace+0x88/0x174)
[<80008e8c>] (prepare_namespace+0x88/0x174) from [<800089e0>] (kernel_init+0x120/0x160)
[<800089e0>] (kernel_init+0x120/0x160) from [<800268b4>] (kernel_thread_exit+0x0/0x8)
我制作ubifs文件系统步骤如下：
1、在kernel中添加ubifs文件系统相关的选项
2、制作ubifs.img文件并烧写经nand flash，但是就是挂载不上，请大虾帮忙分析，谢谢
------解决方案--------------------
1. 制作ubi image的命令行，reference: https://github.com/voiceshen/scripts4linux/tree/master/ubifs
2. 启动系统的命令行参数。
------解决方案--------------------
1.在uboot里，setenv nand_root ubi0:rootfs rw ubi.mtd=2,2048
2.制作imgae时，mkfs.ubifs -c 这个参数要仔细计算，些参数影响较大，再就是改一下ubinize.cfg这个文件的相关参数
3.再说一个我遇到的，开发用了gpio结果一个复用io被改了，结果造成nand read only，这个是驱动造成的，改一下内核驱动就可以了。
我就遇到这些，希望能帮到你。