reg adjust_total_lowmem

[Kumar Gala]

On Oct 25, 2007, at 10:51 PM, Surya Ravikiran wrote:

> Hi,
>
> I am trying to bootup a Linux kernel, on a FS eval board with 256M.
> I pass the kernel argument mem=252M, and see that the kernel boots up
> fine, but with much less memory, ~192M (the closes 64M multiple), and
> I browsed through the code to see that the adjust_total_lowmem
> function does not add up the residual memory to the total memory.
> I am trying to understand why I cannot do this reserving of higher end
> of the RAM during boot up,
> I would appreciate your comments.

The reason you have 192M is that lowmem is the total amount of memory  
that can be covered by up to three CAM entries.  In the case of  
setting mem=252M that max that three CAM entries can cover is 192M (64 
+64+64).  You should be able to access the other 60M via HIGHMEM.

- k