the lowest bit set. This isn't any more or less valid according to the PCI
spec, but it deals with lame devices that don't implement all of the top
bits.
values, i.e. 0xfffffffe and 0xffffffff respectively. The changed
definitions were incorrect, according to the PCI Local Bus Specification
(Revision 2.0). Further rationale and a workaround for the broken
devices that instigated the change provided in a message to
current-users@netbsd.org, dated Mon, 05 Aug 1996 22:06:58 -0400,
message ID 16773.839297218@ux2.sp.cs.cmu.edu>.
(soon to be documented on mailing lists; eventually in section 9 manual
pages), most importantly:
(1) support interrupt pin swizzling on non-i386 systems with
PCI-PCI bridges (per PPB spec; done, but meaningless, on i386).
(2) provide pci_{io,mem}_find(), to determine what I/O or memory
space is described by a given PCI configuration space
mapping register.
(3) provide pci_intr_map(), pci_intr_string(), and
pci_intr_{,dis}establish() to manipulate and print info about
PCI interrupts.
(4) make pci functions take as an argument a machine-dependent
cookie, to allow more flexibility in implementation.
to match. (now, comparisons are comparisons, code doing them doesn't
have to mask.) define types for the various parts of the registers'
contents, where practical.
cgd