HAMs are required to implement automatic hardware detection and driver configuration.
Automatic hardware detection and driver configuration, also known as auto-detect/auto-config, is a feature where the HAM automatically detects its host adapter hardware, if it exists on the server. If the HAM does not detect its adapter, it fails to load. If the HAM detects its adapter (or adapters), it tries to configure the adapter and register the correct options such as ports/slots, interrupts, and DMA channels. After the adapter is configured properly, the HAM is told to scan its buses for attached devices and return information on those devices. The OS then builds a list of these devices and tries to match them with appropriate CDMs via information given in their respective information (.ddi) files. See the Installation Information File Specification (ldi_ddi.pdf) for information to implement this feature.