Re: [2.6.6 PATCH] Exposing EFI memory map

Bjorn Helgaas
2004-05-06T15:08:38Z

On Thursday 06 May 2004 7:20 am, Sourav Sen wrote:
> + 1) Why does userspace / humans need to know this? For
> + debugging firmware?
>
> Maybe. But the point I had in mind is, say for example
> memory diagnostics applications/exercisers which reads (Blind
> reads, without caring about contents) memory
> to uncover errors (single bit errors) can use
> this to know the usable ranges and map them thru /dev/mem and
> read those ranges.

For this application, the EFI memory map isn't what you want.
It's a pretty good approximation today, but the day when we'll
be able to hot-add memory is fast approaching, and the EFI map
won't mention anything added after boot. We'll discover all
that via ACPI (on ia64).