Hi,

What is the possibility of creating a 16MB RAM "cap" for the
INST* kernels, with the 1.2 release?  Limiting the RAM to
16MB during install would have two benefits:
	1.  Joe User can't get dreaded "DMA beyond range"
	    errors if he has a AHA1542/BT542/U14F, and > 16MB RAM.
	    The latest INST* kernels don't support X, so the
	    average user needs to rebuild a kernel anyway.
	2.  Users with > 16MB, but no ISA busmastering devices
	    still could run into the "PTDI" panic problem if
	    they have somewhere between 32-64MB.  >64MB is
	    not yet detected automatically anyway. (unless
	    the new boot code will be in 1.2?)

This _might_ eliminate scenarios where a custom kernel or kernel
copy floppy has to be created.
Perhaps adding a config option EXTMEM_LIMIT that makes sure
the RAM size is <= EXTMEM_LIMIT.
So in the config file:
options		EXTMEM_LIMIT=15360	# Limit to 16MB (ISA DMA issue)

Maybe: (in sys/arch/i386/i386/machdep.c)
...
#ifdef EXTMEM_LIMIT
	if (biosextmem > EXTMEM_LIMIT)
		biosextmem = EXTMEM_LIMIT;
#endif /* EXTMEM_LIMIT */

Just a thought.

-Andrew