Real and availible RAM

Terry Lambert tlambert2 at
Tue May 6 08:05:30 PDT 2003

Eric Anderson wrote:
> I think you missed my point - I wasn't saying that FreeBSD is hiding
> anything, nor was I talking about the "missing 6mb problem" directly.
> You pretty much repeated my point though - "Since the BIOS is where
> FreeBSD obtains the "real memory" number" - which is what I said, that
> the BIOS takes the physical RAM, subtracts what it needs for devices
> like video cards (that "borrow" from physical main memory), then reports
> that result to any OS/Apps/etc that ask for it.  That is why my system
> doesn't show the 256Mb of memory it has in it, it shows something like
> 224Mb (32Mb is set aside for the video card)..
> Unless I am totally missing your point this morning.. :)

You are.  The video memory you are talking about in this case is
accounted for by the AGP or a similar video driver.  It is not
sucked up by the BIOS.  At most, the BIOS will "eat" a few K
(usually, no more than 4K) that is unknown to the OS.

Again, you really need to read the machdep.c code, particularly
the "memsize()" function.

-- Terry

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