# PX4 SD Card Layout

The PX4 SD Card is used for storing configuration files, flight logs, mission information etc.

:::tip
The SD card should be FAT32 formatted for use with PX4 (this is the default for SD cards).
We recommend that you reformat cards that are using a different file system.
:::

The directory structure/layout is shown below.

| Directory/File(s) | 描述                                                                                       |
| ------------------------------------ | ---------------------------------------------------------------------------------------- |
| `/etc/`                              | Extra config. See [System Startup > Replacing the System Startup][replace system start]. |
| `/log/`                              | Full [flight logs](../dev_log/logging.md)                                                |
| `/mission_log/`                      | Reduced flight logs                                                                      |
| `/fw/`                               | [DroneCAN](../dronecan/index.md) firmware                                                |
| `/uavcan.db/`                        | DroneCAN DNA server DB + logs                                                            |
| `/params`                            | Parameters (if not in FRAM/FLASH)                                     |
| `/dataman`                           | Mission storage file                                                                     |
| `/fault_<datetime>.txt`              | Hardfault files                                                                          |
| `/bootlog.txt`                       | Boot log file                                                                            |

[replace system start]: ../concept/system_startup.md#replacing-the-system-startup