dev_t data type

Kernel data type to represent a major / minor number pair

• Also called a device number.

• Defined in <linux/kdev_t.h> Linux 2.6: 32 bit size (major: 12 bits, minor: 20 bits)

• Macro to compose the device number: MKDEV(int major, int minor);

• Macro to extract the minor and major numbers: MAJOR(dev_t dev); MINOR(dev_t dev);