Removing device driver code in mainboard.c for Tyan boards?

YhLu YhLu at
Thu Nov 4 17:44:00 CET 2004

Then every device will need do scan_static_bus.

Also the debug device need to find his parent....


-----Original Message-----
From: Li-Ta Lo [mailto:ollie at] 
Sent: Thursday, November 04, 2004 3:26 PM
To: YhLu
Cc: LinuxBIOS
Subject: RE: Removing device driver code in mainboard.c for Tyan boards?

On Thu, 2004-11-04 at 15:44, YhLu wrote:
> debug device added
>         chip drivers/generic/debug
>                 device  pnp 0.0 on end
>         end
> debug device will be sibling to PCI_DOMAIN and APIC_CLUSTER...

Cool, that is exactly what I want. Actually by defining different debug 
devices, we can construct different 'probes' into the device space.
We can either probe software data structures or the real hardware and
we can do it at different phases of the device enumeration as we want.
For example, the current debug device (pnp 0.0) dumps the PCI CS 
registers at the end of device enumeration. We can define another
debug device to show the topology of the device tree or just print
the famous .name field ;-).

The best thing about the debug device is it totally extensible and
plug/unplugable. We don't have to add any code to the existing device
driver nor the hardwaremain(). It is decoupled from the rest of 
LinuxBIOS. The operations we need to act on the (normal) devices are 
encapsulated in the debug device.


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