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From: Tony Sterrett <tony@nlanr.net>
Message-Id: <199702010346.TAA01593@nlanr.net>
Subject: MAXMEM question
To: hackers@freebsd.org
Date: Fri, 31 Jan 1997 19:46:59 +73600 (PST)
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Hi all:

	I am trying to allocate 1Mb bytes of memory for a special
	custom device. I will need to allocate about 16Mb and they
	must occurs in 1Mb contigous blocks. I have three approaches
	and I'd like know your (all of you) opinon(s):

	1. I reduce that amount of memory bsd thinks I have 
	by changing the value in
	vm_init.c

	vm_set_page_size();
        virtual_avail = vm_page_startup(avail_start, avail_end, virtual_avail);
	and reducing the avail_end and then somehow mapping
	this space into user space.

	2. using vm_page_alloc_contig(size, low, high, alignment)
	to get the memory. I've been trying to use this function
	to get the memory  but I've had no luck doing it, maybe
	I'm parameters I'm
addr = (void *) vm_page_alloc_contig (1048576,25165872, 0x1fffffe, 4096) ; 

	is how I did it.

	3. Some change change to locore.s to set aside.

	So what do you dudes
Cheers,
Tony