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在linux2.6.28后才加入对ubifs的支持 1 查看nand分区 root@ubuntu:~# cat /proc/mtd dev: size erasesize name mtd0: 00020000 00020000 "U-Boot-min" mtd1: 00240000 00020000 "U-Boot" mtd2: 00020000 00020000 "U-Boot Env" mtd3: 00440000 00020000 "Kernel" mtd4: 1f400000 00020000 "File System" mtd5: 00540000 00020000 "Reserved" root@ubuntu:~# cat /proc/partitions major minor #blocks name 31 0 128 mtdblock0 31 1 2304 mtdblock1 31 2 128 mtdblock2 31 3 4352 mtdblock3 31 4 512000 mtdblock4 31 5 5376 mtdblock5 root@ubuntu:~# 2、查看mtd4的信息 root@ubuntu:~# mtdinfo -m 4 -u mtd4 Name: File System Type: nand Eraseblock size: 131072 bytes, 128.0 KiB Amount of eraseblocks: 4000 (524288000 bytes, 500.0 MiB) Minimum input/output unit size: 2048 bytes Sub-page size: 512 bytes OOB size: 64 bytes Character device major/minor: 90:8 Bad blocks are allowed: true Device is writable: true Default UBI VID header offset: 512 Default UBI data offset: 2048 Default UBI LEB size: 129024 bytes, 126.0 KiB Maximum UBI volumes count: 128 root@ubuntu:~# mtdinfo -m 2 -u 或 root@ubuntu:~# mtdinfo /dev/mtd4 mtd2 Name: U-Boot Env Type: nand Eraseblock size: 131072 bytes, 128.0 KiB // FLASH物理擦除块大小 Amount of eraseblocks: 1 (131072 bytes, 128.0 KiB) Minimum input/output unit size: 2048 bytes 1）nor flash:通常是1个字节 2）nand falsh：一个页面 Sub-page size: 512 bytes //对于nand flash来说，子页大小 OOB size: 64 bytes Character device major/minor: 90:4 Bad blocks are allowed: true Device is writable: true Default UBI VID header offset: 512 Default UBI data offset: 2048 Default UBI LEB size: 129024 bytes, 126.0 KiB //逻辑擦除块大小 Maximum UBI volumes count: 128 mtd4大小为500MiB,擦除单元大小(一般即为块大小)为128KiB，名字是"NAND simulator partition 0"。 NandFlash 擦除是以块(block)为单位，读写是以页(page)为单位。 3 root@ubuntu:~# ls -lah /dev/mtd* crw------- 1 root root 90, 0 Jan 1 00:00 /dev/mtd0 //字符设备 crw------- 1 root root 90, 1 Jan 1 00:00 /dev/mtd0ro crw------- 1 root root 90, 2 Jan 1 00:00 /dev/mtd1 crw------- 1 root root 90, 3 Jan 1 00:00 /dev/mtd1ro crw------- 1 root root 90, 4 Jan 1 00:00 /dev/mtd2 crw------- 1 root root 90, 5 Jan 1 00:00 /dev/mtd2ro crw------- 1 root root 90, 6 Jan 1 00:00 /dev/mtd3 crw------- 1 root root 90, 7 Jan 1 00:00 /dev/mtd3ro crw------- 1 root root 90, 8 Jan 1 00:00 /dev/mtd4 crw------- 1 root root 90, 9 Jan 1 00:00 /dev/mtd4ro crw------- 1 root root 90, 10 Jan 1 00:00 /dev/mtd5 crw------- 1 root root 90, 11 Jan 1 00:00 /dev/mtd5ro brw-rw---- 1 root disk 31, 0 Jan 1 00:00 /dev/mtdblock0 //块设备，与mtd0对应 brw-rw---- 1 root disk 31, 1 Jan 1 00:00 /dev/mtdblock1 brw-rw---- 1 root disk 31, 2 Jan 1 00:00 /dev/mtdblock2 brw-rw---- 1 root disk 31, 3 Jan 1 00:00 /dev/mtdblock3 brw-rw---- 1 root disk 31, 4 Jan 1 00:00 /dev/mtdblock4 brw-rw---- 1 root disk 31, 5 Jan 1 00:00 /dev/mtdblock5 root@ubuntu:~# 4. 关于mtd工具集的安装 sudo apt-get install mtd-utils UBI文件系统镜像文件的制作 @ubuntu:~$ sudo mkfs.ubifs -r targetfs -m 2048 -e 129024 -c 3900 -o ubifs.img @ubuntu:~$ sudo ubinize -o ubi.img -m 2048 -p 128KiB -s 512 ubinize.cfg 关于mkfs.ubifs参数的算法 -m minimum I/O unit size -e, --leb-size=SIZE logical erase block size -c maximum logical erase block count -x compression type - "lzo", "favor_lzo", "zlib" or "none" (default: "lzo") -p size of the physical eraseblock of the flash this UBI image is created for in bytes wear_level_reserved_blocks is 1% of total blcoks per device *logical_erase_block_size* is physical erase block size minus 2 pages for UBI Block size = page_size * pages_per_block physical blocks on a partition = partition size / block size Logical blocks on a partition = physical blocks on a partitiion - reserved for wear level File-system volume = Logical blocks in a partition * Logical erase block size 关于参数可以参考attach的命令输出： root@ubuntu:~# ubiattach /dev/ubi_ctrl -m 4 -d 0 UBI device number 0, total 4000 LEBs (516096000 bytes, 492.2 MiB), available 0 LEBs (0 bytes), LEB size 129024 bytes (126.0 KiB) root@ubuntu:~# ubinize.cfg文件 [ubifs] mode=ubi image=ubifs.img vol_id=0 vol_size=450MiB vol_type=dynamic vol_alignment=1 vol_name=rootfs vol_flags=autoresize 5. UBI文件系统镜像在Linux下的烧写 flash_eraseall /dev/mtd4 ubiformat /dev/mtd4 -s 512 -f /xxx/ubi.img 6、 UBI文件系统镜像在U-BOOT下的烧写 //load ubi image to RAM tftp ubi.img //erase MTD4 nand space nand erase 0x6c0000 0xc820000 //write image to nand nand write.i 0x81000000 0x6c0000 0xxxxx(image size) 7. UBI文件系统镜像在Linux下的挂载和卸载 挂载 ubiattach /dev/ubi_ctrl -m 4 -d 0 mount -t ubifs ubi0_0 /mnt/ubi 卸载 umount /mnt/ubi ubidetach -d 0 8、使用ubi做根文件系统 需要在bootargs中设置如下信息：root=ubi0:rootfs ubi.mtd=4 rootfstype=ubifs
配置linux内核
配置的时候选上
1)Device Drivers --->Memory Technology Device (MTD) support --->UBI - Unsorted block images --->Enable UBI
2)File systems --->Miscellaneous filesystems --->UBIFS file system support
这样我们的内核就支持UBIFS文件系统了
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