kconfig

LINUX 2.6.17.4的源码

config PCI
	bool "PCI support"
	help
	  Find out whether you have a PCI motherboard. PCI is the name of a
	  bus system, i.e. the way the CPU talks to the other stuff inside
	  your box. If you have PCI, say Y, otherwise N.

	  The PCI-HOWTO, available from
	  <http://www.tldp.org/docs.html#howto>, contains valuable
	  information about which PCI hardware does work under Linux and which
	  doesn't.

config SH_PCIDMA_NONCOHERENT
	bool "Cache and PCI noncoherent"
	depends on PCI
	default y
	help
	  Enable this option if your platform does not have a CPU cache which
	  remains coherent with PCI DMA. It is safest to say 'Y', although you
	  will see better performance if you can say 'N', because the PCI DMA
	  code will not have to flush the CPU's caches. If you have a PCI host
	  bridge integrated with your SH CPU, refer carefully to the chip specs
	  to see if you can say 'N' here. Otherwise, leave it as 'Y'.

# This is also board-specific
config PCI_AUTO
	bool
	depends on PCI
	default y

config PCI_AUTO_UPDATE_RESOURCES
	bool
	depends on PCI_AUTO
	default y if !SH_DREAMCAST
	help
	  Selecting this option will cause the PCI auto code to leave your
	  BAR values alone. Otherwise they will be updated automatically. If
	  for some reason, you have a board that simply refuses to work
	  with its resources updated beyond what they are when the device
	  is powered up, set this to N. Everyone else will want this as Y.