TODO

 - 10/16/2001: gather info/settings about board specific
   base addresses / IO elementary routines to one (BSP dependent)
   place. This involves fixing the shared BSP.

    hostbridge: identified reading from PCI config space. Note
               that config space addr/data addresses are pointers
               in the 'pci' static struct which is statically inited
               to symbolic constants; all of these things are defined
               in pci/pci.c
        [shared:] identify raven using ptr_mem_map->io_base + RAVEN_OFFSET to 
               probe for the hostbridge. pci structure is initialized
               to addresses taken from ptr_mem_map (console/polled_io.c,
               console/consoleIo.h

    openpic:   base address 'OpenPIC' is read from
               PCI config space in irq/irq_init.c:BSP_rtems_irq_mng_init()
               (ASSUMPTION: 1:1 PCI<->CPU address space mapping)
	[shared:]
		set in pci/pci.c:detect_host_bridge()
                to PCI_BASE_ADDR_1 (from config space) + PREP_ISA_MEM_BASE.

    console:   console/polled_io.c: redefines 'inb' and 'outb'
                to eieio(); *(SVGM_SERIAL_BASE + port - COM1)
               console/uart.c: uread()/uwrite() are modified to access
                hardcoded SVGM addresses.

    irq/irq.h: must leave a hole in the vector table for ISA IRQS for
               reusing the shared code.