how to logically disable memory

[Danny Braniss]

> Reference:
> > From:		Danny Braniss <danny at cs.huji.ac.il> 
> > Date:		Mon, 09 Aug 2004 12:43:24 +0300 
> > Message-id:	<20040809094325.6F8D443D1F at mx1.FreeBSD.org> 
> 
> Danny Braniss wrote:
> > hi,
> > 	is there an 'easy' way to mark some memory as unusable?
> > thanks,
> > 	danny
> 
> You'll hopefully get a better answer than mine, but in case you don't
> & need to start hacking code ...
> 
> Way back on 2.2.8 I disabled all above 16M 'cos one certain manufacturers
> mboard failed to cache & board went slower with more ram !
> 
> Can't remember much now, & doubtless patch doesnt apply now (& that
> 486 board not in service regularly) but it might give a clue where
> to look, looking at
> 
> http://berklix.com/~jhs/src/bsd/fixes/FreeBSD/src/gen/sys/i386/i386/machdep.c.maxmem.diff.ignore
> 
> back then it seemed to be MAXMEM in sys/i386/i386/machdep.c

Hi,
	The short version: I need to disable 'some' physical memory, it's bad,
and so far can't find it to change it :-).

	The long version: this is an IBM Thinkpad X40, quiet new, that
lost it's warranty because somehow 'some liquid' was spilled on the keyboard.
It seems to have some 512M of memory on the motherboard, which after an
almost total dissasembly could not find. Windows crashes too often, but
FreeBSD is doing fine. So if i can just disable parts of it (memtest has
found the bad memory) then this is a neat notebook.

danny