Linux allocated devices in the Linux kernel documentation

Linux Device List, official registry of allocated device numbers and device-node names. Opening notes discuss dynamic allocation. Entry1 distinguishes character memory devices, including minors3 for /dev/null and5 for /dev/zero, from block major1 for RAM disks.

Companion primary API documentation: docs.kernel.org/core-api/kernel-api.html#char-devices . register_chrdev_region reserves a requested range; alloc_chrdev_region dynamically chooses the major and returns the first assigned number. Numerical reservation, cdev registration and /dev naming are distinct operations. The main registry distinguishes character and block assignments, including separate uses of major 1.