format

Command Function

This command is used for disk formatting.

Syntax

format <dev_inodename> <sectors> <option> [label]

Parameters

Table 1 Parameter description

Parameter

Description

dev_inodename

Specifies the device name.

sectors

Specifies the size of the allocated memory unit or sector. The value 0 indicates null. (The value must be 0 or a power of 2. For FAT32, the maximum value is 128. If the parameter is set to 0, a proper cluster size is automatically selected. The available cluster size range varies depending on the partition size. If the cluster size is incorrectly specified, the formatting may fail.)

option
Specifies the file system type. The options are as follows:
  • 0x01: FMT_FAT
  • 0x02: FMT_FAT32
  • 0x07: FMT_ANY
  • 0x08: FMT_ERASE (not supported by the USB flash drive)

If an invalid value is specified, the system automatically selects the formatting mode. If the low-level formatting bit is 1 during the formatting of a USB flash drive, an error message is printed.

label

Specifies the volume label name. This parameter is optional, and the value is a string. If null is specified for this parameter, the previously set volume label name is cleared.

Usage

  • The format command is used for disk formatting. You can find the device name in the dev directory. A storage card must be installed before the formatting.
  • The format command can be used to format the USB flash drive, SD card, and MMC, but not the NAND flash or NOR flash.
  • An invalid sectors value may cause exceptions.

Example

Run format /dev/mmcblk0 128 2.

Output

Formatting an MMC:

OHOS # format /dev/mmcblk1 128 2
Format to FAT32, 128 sectors per cluster.
format /dev/mmcblk1 Success