[ros-kernel] RE: Bus drivers

[Casper H. <ch...@us...>]

> -----Original Message-----
> From: Phillip Susi [mailto:ps...@cf...] 
> Sent: 2. november 2001 01:23
> To: ros...@re...
> Subject: [ros-kernel] Bus drivers
> 
> 
> What is the status with the bus drivers?  acpi and pci.

All bus drivers need most of the PnP and power IOCTLs implemented
(both for the bus device object and child device objects).
They all scan their busses and reports the devices that
are found to the PnP manager. The PnP manager queries the
bus driver for things like Ids and resource requirements
and stores this in the registry. The information is also
used to build the device tree. Due to a bug in the registry,
ReactOS crashes when too much is stored in the registry.

> What do they do and should I be loading them?

Unless you want to work on the PnP system or converting a
driver to PnP, it won't do you any good to load them.

> I think the purpose of the drivers is to be 
> the root bus driver to enumerate all other devices in the 
> system for the WDM PnP system to load PnP drivers.

In NT, the root bus enumerator is part of the PnP manager. It
enumerates legacy devices by scanning the registry. It also
handles PnP and power IRPs for legacy devices. The primary bus
enumerator (usually PCI) is stored in the registry and is loaded
as a boot driver. It scans it's bus(ses) to locate other busses
and (if the service for the device is specified as a boot driver
in the registry) loads and initializes the driver for the device.
Later when all boot drivers have been initialized, the PnP manager
initializes system start drivers and any child devices if they
exist.

> Are we trying to move to WDM and PnP, 
> and if so, how far are we?

I would like to ;o)

We need to convert a legacy driver to PnP to test the PnP functions.
Virtually all PnP API functions needs to be implemented. Having a
PnP driver would make it easier to test the PnP API. I think
floppy.sys or disk.sys would be a good place to start.

  Casper

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