Toshiba 64M limit and slram (was Toshiba ToPIC developer info)
Ryan Underwood
nemesis-lists at icequake.net
Wed Jun 22 15:55:57 EDT 2005
On Wed, Jun 22, 2005 at 10:16:21AM +0100, Russell King wrote:
>
> Unfortunately, the kernel needs to know how much RAM you really have so
> it can properly allocate memory resources. Lying to it (by passing mem=)
> is generally a recipe for disaster.
I was under the impression that using the mem= parameter simply
truncated the high memory area, so the kernel would behave as if you
only had that amount of memory installed.
> However, if slram is making use of some area of memory, it really should
> reserve it. That's a slram bug - please report it to the mtd mailing
> list.
I will do so. However, it seems impossible for slram to reserve i.e.
64M-160M area unless the kernel is disallowed from using it for other
reasons. Surely something would be allocated there already by the
time slram was activated.
> Even with slram fixed, there remains the danger of something trying to
> allocate a resource _before_ slram claims its resource... I just hate
> the entire mem= mess entirely for this very reason. It's completely
> unsafe.
What is the best thing to do then? Ever since slram was designed, it
has assumed that the user would set the mem= option appropriately. I've
had the 'reserve' option pointed to me but not tried it yet.
--
Ryan Underwood, <nemesis at icequake.net>
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