Re: reserve memory in low physical address - possible?

Paul Mundt
2006-10-31T08:13:16Z

On Mon, Oct 30, 2006 at 11:22:03PM -0800, Jun Sun wrote:
> I understand it is possible to reserve some memory at the end by
> specifying "mem=xxxM" option in kernel command line. I looked into
> "memmap=xxxM" option but it appears not helpful for what I want.
>
memmap takes multiple arguments, including the start address for the
memory map. You could also bump min_low_pfn manually if memmap= isn't
suitable for you, something like:

magic_space = PFN_UP(init_pg_tables_end);
min_low_pfn = magic_space + magic_size;

(assuming magic_size is rounded up already), should work fine. Though
memmap= already takes care of most of this for you, could you explain why
it's unsuitable?