Fix for boot issue: Don't disable BARs on AGP devices. In general: Don't disable BARs on any PCI display devices, because doing that can sometimes cause the main memory bus to stop working, causing all memory reads to return nothing but 0xFFFFFFFF, even though the memory location was previously written.  After a while a privileged instruction fault will appear and then nothing more can be debugged. The reason for this behaviour is unknown.
Fix for boot issue: Don't disable BARs on AGP devices. In general:
Don't disable BARs on any PCI display devices, because doing that can
sometimes cause the main memory bus to stop working, causing all
memory reads to return nothing but 0xFFFFFFFF, even though the memory
location was previously written.  After a while a privileged
instruction fault will appear and then nothing more can be debugged.
The reason for this behaviour is unknown.

MFC after:	1 week

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