In message: <[EMAIL PROTECTED]> Bruce M Simpson <[EMAIL PROTECTED]> writes: : On Sun, Apr 09, 2006 at 06:48:25PM -0600, M. Warner Losh wrote: : > I though thtis was already supported. We export bus/slot/function : > information devd, which can be used to configure the device. : : If I've read the specs or code incorrectly please do let me know -- : my reading here is based on the PCI code as I understand it to be. : : As I understand things, the bus/slot/function numbers in pci(9), the : *slot* number isn't guaranteed to have any meaning in geographic reality; : it's purely what the PCI logic thinks the bus topology looks like and : hence what the device numbers are. See BUGS in pci(9).
The device number is fixed for a given mother board slot. It will never change unless you change the mother board. However, for stacking topologies the slot is the position in the stack. : It won't tell you that a given card is in a given slot with any degree : of certainty or consistency across the range of backplanes available : from multiple vendors -- although people may like to give PICMG a try : as I hear such boards are consistent about such things. Correct. : In the old Microsoft-specified $PIR tables there was a column which : allowed you to map the bus/device/function tuple we use to a physical : slot number, but this only ran 1-6. With multiple PCI buses and slot : types, as well as multifunction devices, this information quickly became : unusable and unreliable, although src/tools/tools/pirtool will happily : display this information. Correct. : ACPI as you no doubt know does away with the $PIR tables, although many : BIOS still export them to allow legacy DOS programs which use PCI to work. : There is an extension to ACPI which adds geographical slot addressing : to the device tree but I haven't seen any systems which support it. OK. Physical slot information. Warner _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"