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Date:      Wed, 9 Aug 2006 14:31:49 -0400
From:      John Baldwin <jhb@freebsd.org>
To:        Krassimir Slavchev <krassi@bulinfo.net>
Cc:        Julian Stacey <jhs@berklix.org>, freebsd-hardware@freebsd.org
Subject:   Re: Real and available memory?
Message-ID:  <200608091431.50183.jhb@freebsd.org>
In-Reply-To: <44D9D8D0.1020704@bulinfo.net>
References:  <200608090908.k79988pY086073@fire.jhs.private> <200608090832.30259.jhb@freebsd.org> <44D9D8D0.1020704@bulinfo.net>

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On Wednesday 09 August 2006 08:45, Krassimir Slavchev wrote:
> John Baldwin wrote:
> > On Wednesday 09 August 2006 06:13, Krassimir Slavchev wrote:
> >   
> >> Julian Stacey wrote:
> >>     
> >>> Reference:
> >>>   
> >>>       
> >>>> From:		Krassimir Slavchev <krassi@bulinfo.net> 
> >>>> Date:		Wed, 09 Aug 2006 11:46:33 +0300 
> >>>> Message-id:	<44D9A0E9.30608@bulinfo.net> 
> >>>>     
> >>>>         
> >>> Krassimir Slavchev wrote:
> >>>   
> >>>       
> >>>> Julian H. Stacey wrote:
> >>>>     
> >>>>         
> >>>>> Krassimir Slavchev wrote:
> >>>>>   
> >>>>>       
> >>>>>           
> >>>>>> Julian H. Stacey wrote:
> >>>>>>     
> >>>>>>         
> >>>>>>             
> >>>>>>> Krassimir Slavchev wrote:
> >>>>>>>   
> >>>>>>>       
> >>>>>>>           
> >>>>>>>               
> >>>>>>>> Hello,
> >>>>>>>>
> >>>>>>>> I have Vortex86-6082 with 128Mb AMI bios.
> >>>>>>>>
> >>>>>>>> Why the kernel reports only 80 MB available memory?
> >>>>>>>> Is this related to BIOS or kernel settings?
> >>>>>>>>
> >>>>>>>> dmesg output:
> >>>>>>>>
> >>>>>>>> Copyright (c) 1992-2006 The FreeBSD Project.
> >>>>>>>> Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
> >>>>>>>>         The Regents of the University of California. All rights reserved.
> >>>>>>>> FreeBSD 6.1-STABLE #0: Wed Jul 26 10:09:06 EEST 2006
> >>>>>>>>     root@krassi:/usr/obj/usr/src/sys/TINYBSD
> >>>>>>>> Timecounter "i8254" frequency 1193182 Hz quality 0
> >>>>>>>> CPU: Pentium (166.61-MHz 586-class CPU)
> >>>>>>>>   Origin = "SiS SiS SiS "  Id = 0x505
> >>>>>>>> real memory  = 125829120 (120 MB)
> >>>>>>>> avail memory = 84332544 (80 MB)
> >>>>>>>> kbd1 at kbdmux0
> >>>>>>>> ...
> >>>>>>>>     
> >>>>>>>>         
> >>>>>>>>             
> >>>>>>>>                 
> >>>>>>> Does the mboard BIOS on monitor at boot recognise all 128 M ? 
> >>>>>>>
> >>>>>>> I've seen boards that only recognised 1/4 of the SIM size.
> >>>>>>> 80 seems a bit of an odd (non hex) number though.
> >>>>>>>
> >>>>>>>   
> >>>>>>>       
> >>>>>>>           
> >>>>>>>               
> >>>>>> Yes, at boot the board recognizes 128Mb. The RAM is embedded on the board.
> >>>>>> The kernel reports real 120 Mb because maybe 8 Mb is used by video card.
> >>>>>> I don't know why exact 80Mb is reported but 80 = 64+16.
> >>>>>>     
> >>>>>>         
> >>>>>>             
> >>>>> Have you tried unplugging every board (inc. ethernet scsi raid etc)
> >>>>> & plugging in a different (modest, old as possible. less demanding)
> >>>>> graphic card ? Maybe that'd give a clue, maybe your graphics card
> >>>>> is taking more than 8M ?
> >>>>>
> >>>>>   
> >>>>>       
> >>>>>           
> >>>> No, I can't unplug anything, see: 
> >>>> http://www.icop.com.tw/products_detail.asp?ProductID=119
> >>>>     
> >>>>         
> >>> Interesting little board, (might be of interest to other freebsd.org
> >>> mail lists eg small, real time ).
> >>>
> >>> That URL specifies
> >>> 	128MB SDRAM
> >>> 	...
> >>> 	AGP Rev.2.0 compliant
> >>> 	Shared system memory up to 64MB (Default 8 MB)
> >>> Maybe BIOS is no longer defaulting to 8 Meg ?
> >>> Checkable / Settable in BIOS ?
> >>>
> >>>   
> >>>       
> >> I can't find anything related to video memory in the BIOS but it seems 
> >> to be correct
> >> real memory = 120 Mb reported by the kernel.
> >> My question is why the available memory  is only 80Mb?
> >>     
> >
> > Are you using an MFS root or a really large kernel?
> >
> >   
> Yes, MFS root is 32 Mb and kernel is ~3.4Mb

Well, that's where the missing 40 meg is. :)  The kernel text (including
any modules and preloaded mfsroot's) aren't include in the 'avail memory'
count.

-- 
John Baldwin



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