RTEMS-mvme5500 BSP update

[Kate Feng]

Hi,

The stable version of RTEMS-mvme5500 BSP is posted at
http://www.nsls.bnl.gov/facility/expsys/software/EPICS/
The "RTEMS-mvme5500 BSP v1.4.9.1", was tested
under RTEMS 4.9.1, and the "RTEMS-mvme5500 BSP v1.4.8.0"
was tested under RTEMS 4.8.0..

The highlights of the change are :

1)  Use the GT_GPP_Value register (0xf104) instead of the
GT_GPP_Interrupt_Cause register (0xf108) to monitor the cause
of the level sensitive interrupts. See irq/BSP_irq.c.
This is an unique solution which solves part of the bugs in
the BSP, which especially affects the 1GHz network driver.

2) There is no change in the 100 MHz network driver. Thus,
its performance stays the same.  Some bugs were fixed in the
1GHz network drivers (e.g. if_wm.c).

3)Enable "PCI Read Agressive Prefetch", "PCI Read Line Agressive Prefetch",
and "PCI Read Multiple Agressive Prefetch" to improve the performance of
the PCI based applications (e.g. 1GHz network driver). See 
pci/pci_interface.c.
However, performance is driven by applications.

There is no known bug at this point.  Any feedback which is related to
the RTEMS-mvme5500 BSP would be highly appreciated.

Hope this helps,
Kate