Misc Devices: The Short Path to One Device File
Claiming a whole major number is overkill for a driver that only needs one device file, so the kernel offers a shared major number and a tiny registration where you give a name and a set of operations and get a device file back. It is the least-ceremony way to make a driver reachable from user space, and it is what samples and single-device drivers use. The trade-off is that it fits only simple cases; something needing many numbered devices outgrows it.
Questions this Concept answers
- Why does the misc device path exist alongside full character device registration?
Miscellaneous Device Registration in Linux Kernel Driver Development
A miscellaneous device is a simplified character-device registration interface in the Linux kernel that lets a driver expose a single /dev node without allocating and managing a dedicated major numbe…