Service_USB 8 - Sub host controller removed
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## Name

Service_USB 8 - Sub host controller removed — Used for communications between USB Host Controller drivers. Shows that a sub host controller driver has been removed.

## On Entry

R0 | 8 (reason code)
R1 | &80C00 (USB Service call)
R2 | Pointer to a list of sub driver properties, used as a unique tag.

## On Exit

All registers preserved to pass on, else

R0 | preserved
R1 | 0 to claim.
R2 | preserved

## Use

Some Host controller drivers are split into two parts a generic device type handler and a specific hardware dependent support module. This allows one host controller type to have numerous differing hardware implementations without needless duplication of code.

This service call is issued by a main host class driver before it is removed. This allows any sub drivers to perform any necessary finalisation. The sub driver may claim the service to prevent the host class drivers removal.

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Service_USB 7 - Sub host controller driver has been started. | Home | Service_USB 16 - USB system module started