Re: [PATCH] ACPI: Implement overriding of arbitrary ACPI tables via initrd

H. Peter Anvin
2012-03-24T04:59:01Z

On 03/23/2012 09:50 PM, Yinghai Lu wrote:
> On Fri, Mar 23, 2012 at 9:43 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>>> Can this be implemented without using dynamic memory allocations?
>>> If not, it's not suitable for early APCI overriding.
>>
>> Yes it can, as long as it is uncompressed. It just becomes a matter of
>> walking the cpio headers which is effectively a linked list.
>
> During checking in reserve_inirtd() (BTW, the name of the function is outdated).
> memblock is ready.
> So dynamical memory allocation is there already.
>
> also could put that headers in the tail, so old intird utilities could
> work as before.
>

We could; I'm not sure if that would be an improvement or not.

However, for the microcode update stuff this needs to happen long before
memblock exists, so it's not really an option. However, it's not a
problem, as the whole initrd blob needs to be reserved for that duration.

-hpa