Where is Configfs?
/sys/kernel/config
Configfs is for creating, managing and destroying kernel objects from user-space, and sysfs for viewing and manipulating objects from user-space which are created and destroyed by kernel space. It is typically mounted at /sys/kernel/config (or more rarely at /config ).
What is configfs in linux?
configfs is a ram-based filesystem that provides the converse of sysfs’s functionality. With sysfs, an object is created in kernel (for example, when a device is discovered) and it is registered with sysfs. Its attributes then appear in sysfs, allowing userspace to read the attributes via readdir(3)/read(2).
What is FunctionFS?
From user space point of view it is a file system which when mounted provides an “ep0” file. Again, FunctionFS takes care of the real numbers and changing of the configuration (which means that “ep1” file may be really mapped to (say) endpoint 3 (and when configuration changes to (say) endpoint 2)).
What is sysfs in Linux?
sysfs is a pseudo file system provided by the Linux kernel that exports information about various kernel subsystems, hardware devices, and associated device drivers from the kernel’s device model to user space through virtual files.
What is LibComposite?
LibComposite solves those problems by putting the configuration into userland (ConfigFS). Keep in mind though, that at the time of writing, no windows drivers are available – you need to use Linux or Mac OS X to connect to your Pi this way.
What is USB gadget?
The term “USB Gadget” will usually refer to the Linux USB gadget framework. This is relevant for those sunxi devices that offer a “On-The-Go” (OTG) port, allowing this USB connector to act in a “dual role” mode. Composite gadgets: Multifunction composite, Ethernet & ACM, ACM & mass storage, Nokia composite.
What is USB controller?
A USB Host Controller is the hardware either on the computer motherboard or PCI card. It provides an interface for transferring streams of data between the host computer and the USB devices. The host computer may have one or multiple USB host controllers with different types of interface.
What is a gadget driver?
Gadget drivers for device classes such as storage, networking, and serial converters. These drivers answer to their class when they receive enumeration requests from host-side software.
How does a config _ item in Configfs work?
A config_item reflects an object in the subsystem. It has attributes that match values on that object. configfs handles the filesystem representation of that object and its attributes, allowing the subsystem to ignore all but the basic show/store interaction. Items are created and destroyed inside a config_group.
Where is the Configfs located in the kernel?
Configfs is for creating, managing and destroying kernel objects from user-space, and sysfs for viewing and manipulating objects from user-space which are created and destroyed by kernel space. It is typically mounted at /sys/kernel/config (or more rarely at /config ).
Is the Configfs tree always in / config?
The configfs tree will be empty unless client modules are also loaded. These are modules that register their item types with configfs as subsystems. Once a client subsystem is loaded, it will appear as a subdirectory (or more than one) under /config. Like sysfs, the configfs tree is always there, whether mounted on /config or not.
What’s the difference between sysfs and Configfs?
Where sysfs is a filesystem-based view of kernel objects, configfs is a filesystem-based manager of kernel objects, or config_items. With sysfs, an object is created in kernel (for example, when a device is discovered) and it is registered with sysfs.