ArduPilot File Systems

ArduPilot uses several files systems to store and retrieve data from non-volatile storage using either external SD cards or autopilot flash memory.

External SD Card

The directory structure is:


and a vehicle backup file (one for each vehicle class that the card has been used) that contains ???

Flash based virtual file systems

Several flash based file systems are setup. Most are for internal, ground station, or developer use only, but one is useful for normal users.

  • @ROMFS: this contains a copy of the bootloader version created with the firmware that is loaded which is used if a bootloader update is commanded from an attached ground station or pc utility. It also contains a copy of the hardware definition file, and font files if OSD support is included.

  • @PARAM: this is a packed version of the firmware’s parameters which can be downloaded from the ground control station.

  • @SYS: which contains several text files that keep statistics of internal operational processes for information and debugging issues (really the only one a normal user may be asked to access to send information when debugging a user issue):
    • threads.text: information on the concurrent process threads during operation

    • tasks.text:

    • dma.text:

    • memory.txt:

    • uarts.txt: