Creaton and removal of HAL devices

Hardware Abstraction Layer

» HAL Device API

» Creation and removal of devices

Adding devices – from the HAL

Once the OS calls HAL_InitDevices, the HAL is free to register as many devices it wants, whenever it wants. However it’s usually best to register all the devices inside the implementation of HAL_InitDevices, to ensure that they’re made available to the OS as early as possible during initialisation.

RISCOS_AddDevice is the entry point that the HAL should use to register a device with the OS.

Note that it is not possible for the HAL to deregister devices.

Adding devices – from the OS

SWI OS_Hardware 2 should be used to register devices.

Removing devices – from the OS

SWI OS_Hardware 3 should be used to deregister devices.

Enumerating and detecting devices

SWI OS_Hardware 4 can be used to search the device list for devices of a specific type.

Service_Hardware is issued by the OS when devices are registered and deregistered.

Information source: Kernel.Docs.HAL.NewAPI in CVS