bootloader. Implement the following routines:
pcibios-device-count count the number of instances of a devid
pcibios-read-config read pci config space
pcibios-write-config write pci config space
pcibios-find-devclass find the nth device with a given devclass
pcibios-find-device find the nth device with a given devid
pcibios-locator convert bus device function ti pcibios locator
These commands are thin wrappers over their PCI BIOS 2.1 counterparts. More
informaiton, such as it is, can be found in the standard.
Export a nunmber of pcibios.X variables into the environment to report
what the PCI IDENTIFY command returned.
Also implmenet a new command line primitive (pci-device-count), but don't
include it by default just yet, since it depends on the recently added
words and any errors here can render a system unbootable.
This is intended to allow the boot loader to do special things based
on the hardware it finds. This could be have special settings that are
optimized for the specific cards, or even loading special drivers. It
goes without saying that writing to pci config space should not be
done without a just cause and a sound mind.
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