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Bus Enumeration: How a System Finds Its Devices

Enumeration is the start-up walk in which the system asks a bus what is plugged into it, and each device answers with an identity and a list of the resources it needs. The result is a list of devices the operating system can match drivers against, which is why plugging in a card is usually enough to make it work. Buses that cannot be asked, like the wiring inside a phone chip, need the device list supplied some other way.

Questions this Concept answers

  • Why do the buses inside a system-on-chip need their device list supplied from somewhere else?