Configfs

Applicable for

STM32MP13x lines, STM32MP15x lines, STM32MP25x lines

1. Introduction[edit | edit source]

Configfs^[1] is a RAM-based filesystem that provides the converse of sysfs functionality.

While sysfs provides a filesystem-based view of kernel objects, configfs is a filesystem-based manager of kernel objects or config_items (every object in configfs is a config_item). This means that kernel objects can be created, managed and destroyed from the user space.

2. Installing configs on your target board[edit | edit source]

Configfs can be enabled and ready to be used in all STM32MPU Embedded Software distribution, via the Linux^® kernel configuration CONFIG_CONFIGFS_FS (set to yes by default):

Symbol: CONFIGFS_FS
Location:
  File systems --->
    Pseudo filesystems -->
      -*- Userspace-driven configuration filesystem

Please refer to Menuconfig or how to configure kernel article for instructions for modifying the configuration and recompiling the Linux kernel image in the Distribution Package context.

3. Getting started[edit | edit source]

3.1. How to mount configfs[edit | edit source]

Use the following command to mount Configfs at /sys/kernel/config:

mount -t configfs none /sys/kernel/config

3.2. How to set and manage configfs from Linux kernel drivers and user space[edit | edit source]

Refer to the Linux documentation^[1] for detailed information.

Configfs is used by the USB framwework. Refer to USB API description for an example.

4. References[edit | edit source]

↑ ^1.0 ^1.1 Documentation/filesystems/configfs.rst

[configfsdoc-1] 1.0 ^1.1 Documentation/filesystems/configfs.rst

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