How to determine amount of RAM installed?

[John-Mark Gurney]

Stefan Farfeleder wrote this message on Tue, Jul 15, 2003 at 21:21 +0200:
> On Tue, Jul 15, 2003 at 11:27:24AM -0700, David O'Brien wrote:
> > How can one get RAM properties from OBP?  Specifically how much RAM is
> > installed?
> 
> dev /memory
> .properties
> 
> The first value of 'available' should be the start address, the second
> one the number of bytes of installed memory.

Ok, this is a start but not very useful (esspecially wrt 64bit ppc)..

To properly parse the reg or available property, you need to get the
#address-cells and #size-cells property from the parent node.  If the
address-cells doesn't exist, assume it to be 2, and if the size-cells
property doesn't exist, assume it to be 1.

The available property is memory that hasn't been allocated by the OFW,
and reg is the absolute physical memory.

So, on a g3 notebook, you have something like:
0 > dev / ok
0 > .properties
[...]
#address-cells	00000001
#size-cells	00000001
[...]
ok
0 > dev /memory ok
0 > .properties
[...]
reg		00000000  04000000
		04000000  10000000
available	00003000  13dfd000

and a cell is defined as 4 bytes.  So, you can see where the memory is
and the size of it.  The first 0x3000 bytes of memory is currently used
by OFW, with 0x13dfd000 memory available.

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."