What Are The Main Drivers In Java?

The Java Programming Standard Edition libraries are substantial, and require a great deal of support from the JVM. The kernel environment is limited. The facilities required by kernel extensions are more limited in scope and different from those of user applications.

A device driver will typically loadable in kernel module containing the implementations of the required or called functions. In response to system calls, the kernel locates and calls the appropriate device driver function. For example, when a driver module is first loaded, the driver's_init function is called so that the device driver can perform initializations, such as allocating kernel resources. Conversely, _fini is called before the module is unloaded. This is a  list of  device driver functions:

probe checks that the device is ready
attach is called when a device is attached
detach is called when a device is detached
getinfo gets configuration information from the driver
open opens the device
close closes the device
read reads from the device
write writes to the device

A device driver developer has to implement the each function on device-specific version. Pointers to the functions are passed, encapsulated in a struct dev_ops, to the modinstall function, which installs the driver and is typically called from within the driver's _init function. The device driver interface uses a single object to contain the methods that
would correspond to the functions and the pointers to them within a struct dev_ops.


A driver is written by subclassing the abstract device driver class, Device Driver. Device Driver provides access to different kernel functions and data structures in the form of Java native methods and classes that wrap pointers to structs, as well as abstract method declarations for the driver functions.