Subscribe to a registered service by name. This will deliver a notification to the task that registered the service with one end of a newly created channel. The other end of the channel will be returned by this system call, if successful.
See the section on Services for more information about services, how to register a service, and how to subscribe to a service.
a- the length of the name string in bytes. Maximum length is 256. Must be greater than
b- a usermode pointer to the start of the UTF-8 encoded name string.
Returns the standard representation of a
Result<Handle, ServiceError>. Error status codes are:
1if the task does not have the correct capability
2if the usermode pointer to the name is not valid
3if the name is too long, or
4if the supplied name does not correspond to a registered channel.
The returned handle is to one end of a
Channel, the other end of which has been given to the task that supplies
ServiceUser capability is needed to make this system call.