Re: patch/option to wipe memory at boot?

[Jeremy Fitzhardinge <jeremy@goop.org>]

David Madore wrote:
> Is there a patch or a boot option or something which wipes all
> available (physical) RAM at boot (or better, fills it with a fixed
> signature like 0xdeadbeef)?  I'm getting phony ECC errors and I'd like
> to test whether they go away when the RAM is properly initialized.
> Also, I'd like to know exactly which parts of RAM are being used and
> which are untouched since boot (hence the 0xdeadbeef signature).
>
> If this patch/option doesn't exist, can anyone give me a hint as to
> where and how it would be best to add this?  (I'm afraid I'm very
> ignorant as to how Linux sets up its RAM mapping.)  I'm concerned
> about x86 and x86_64.
>
> PS: I'm not finicky: it's all right if a couple of megabytes at the
> bottom of RAM are not scrubbed (I'm more interested about the top
> gigabyte-or-so), especially if they're guaranteed to be used by the
> kernel.
>   

Boot memtest86 for a little while before booting the kernel?  And if you
haven't already run it for a while, then that would be your first step
anyway.

    J