How do i find all the pci devices in the system?

Hi,

I'm new to NetBSD kernel.

I'm planning to list all the PCI devices in the users space.

Modifying the pciconf.c downloaded from FreeBSD to the NetBSD.
In the sys/dev/pci/pci_usrreq.c file i can found the options for
Read/Write on conf buf.
But could not find the option to list all the pci devices found in the system.

Is there any way to search manually all the pci devices and access them?

Please advice.

Thanks,
Gnana