> Services Title: DeviceFS Service calls
Authors: David De Vorchik, Tim Dobson
History:
19-Apr-91 DDV Created.
20-Apr-91 DDV Improved information on Service_DeviceDead (r3).

        29-May-91 TMD Corrected some typos.

INTRODUCTION

DeviceFS will issue several service calls during its time, it issues them to inform the device drivers when it has been installed, it is about to die and when a particular device has been killed.

The following can be generated:

Service_DeviceFSStarting (&70)
Service_DeviceFSDying (&71)
Service_DeviceDead (&79)

Service_DeviceFSStarting

in: r1 = Service_DeviceFSStarting

out: -

This code is issued when the module wants the device drivers to re-register with DeviceFS, the call is issued during the module initialisation. In this case it is actually issued on a callback to ensure that the module has been correctly linked into the module chain.

Service_DeviceFSDying

in: r0 = 0

      r1   = Service_DeviceFSDying
      

This is issued when DeviceFS is about to be killed, the device driver will already have had all of its streams closed and will have received the DeviceFS_DeviceDead service.

Service_DeviceDead

in: r0 = 0

      r1   = Service_DeviceDead
      r2   = handle of device / =0 if all
                if r2 >0 then
                      r3  -> device name (r1 +0 on register) / =0 if parent dead

out: -

This is issued to inform the specified device that it has been killed, this is usually caused when another device of the same name is registered and the original one has been killed to stop duplicates.