linux下通过命令格式化SD卡

步骤一：

查看系统中是否有

步骤二：

sudo fdisk /dev/sdb 

输入m会出现命令类表，简洁而强大

Command (m for help): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only) 

输入p查看当前sd卡的分区(partition)信息

Command (m for help): p Disk /dev/sdb: 7948 MB, 7948206080 bytes 245 heads, 62 sectors/track, 1021 cylinders, total 15523840 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdb1 * 2048 1048576 523264+ c W95 FAT32 (LBA) /dev/sdb2 1048577 15523839 7237631+ 83 Linux 

其中，需要记住的是他的容量7948206080 bytes之后会用到。
同时也留意他的heads和setcors/track

删除分区

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输入d删除(delete)所有sd卡分区。因为有2个分区，需要删除2次

Command (m for help): d Partition number (1-4): 1 Command (m for help): d Selected partition 2

建立分区

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输入n新建(new)一个分区

输入p选择新建一个主分区

输入1创建分区1

输入分区1的‘First sector’和‘Last sector’

Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) e extended Select (default p): p Partition number (1-4, default 1): 1 First sector (2048-15523839, default 2048): 2048 Last sector, +sectors or +size{K,M,G} (2048-15523839, default 15523839): Using default value 15523839 

在新建分区时可以根据实际情况设置分区大小，如果不设置，直接进行回车，会使用默认值。

输入w将建立完成对分区表写入sd卡，并退出

Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: If you have created or modified any DOS 6.x partitions, please see the fdisk manual page for additional information. Syncing disks.

步骤三：

sudo mkfs.ext3 /dev/sdb2 -L LABEL2

/dev/sdb2后面的参数根据情况进行设定 mkfs.ext3表示将分区格式化成ext3类型

说明：如果在ARM上进行格式化操作，则mkfs.ext3需要为交叉编译