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Date:      Wed, 13 Mar 1996 11:58:40 -0500 (EST)
From:      hoek@freenet.hamilton.on.ca
To:        Robin Lunn <robin@is.co.za>
Cc:        doc@freebsd.org
Subject:   Re: Kernel only sees 64Mb of RAM
Message-ID:  <Pine.SOL.3.91.960313115616.11193A-100000@james.freenet.hamilton.on.ca>
In-Reply-To: <199603131458.QAA22752@admin.is.co.za>

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On Wed, 13 Mar 1996, Robin Lunn wrote:

> We've just installed FreeBSD 2.1.0-RELEASE onto a P-100 with 128Mb of ram.
> The kernel (as yet only the GENERIC kernel) only sees 64Mb of memory.  I see
> no special definitions in the GENERIC kernel config file on my development
> system that would cause it to be limited as such.

>From question 8.6 of the FreeBSD-faq,  :-)

     _________________________________________________________________
   
8.6. I have 128 MB of RAM but it seems that the system use only the first 64
MB. What's going on ?

   
   
   Due to the manner in which FreeBSD gets the memory size from the BIOS,
   it can only detect 16 bits worth of Kbytes in size (65535 Kbytes =
   64MB). If you have more than 64MB, FreeBSD will only see the first
   64MB. To work around this problem, you need to use the kernel option
   specified below. There is a way to get complete memory information
   from the BIOS, but we don't have room in the bootblocks to do it.
   Someday when lack of room in the bootblocks is fixed, we'll use the
   extended BIOS functions to get the full memory information...but for
   now we're stuck with the kernel option.
   
   
     _________________________________________________________________
   

            options "MAXMEM=<n>"

   
     _________________________________________________________________
   
   Where n is your memory in Kilobytes. For a 128 MB machine, you'd want
   to use 131072
     _________________________________________________________________
   

--
tIM...HOEk.....Outnumbered, maybe, but outspoken?!  NEVER!



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