Subject: [Linaro-acpi] Touching the initrd before paging_init

From: [email-masked] (Jon Masters)
Date: Sun, 13 Dec 2015 17:15:24 -0500

On 12/13/2015 05:02 PM, Jon Masters wrote:
> On 12/13/2015 04:36 PM, Jon Masters wrote:
> 
>> Just thinking from a parity point of view - if you can do it on x86, it should be
>> doable on ARM. But that GRUB module approach I quite like!
> 
> Sorry for top post earlier. Was on my phone. In any case, it looks like
> the "acpi" command in GRUB currently does an all-or-nothing replace of
> all of the tables, not just a named table. We need to be able to
> override e.g. just an DSDT or SSDT with a replacement test one.

I rescind that. Looking at the GRUB source clarifies things. It will
copy all host tables, then update the copied version if there are
additional tables with changes and recalculate checksums/pointers in the
XSDT etc. I seem to recall having looked at this before a couple years
ago or something and it might have grown some of the 64-bit XSDT logic
in that time. Either way, it does seem to do what I wanted. I will
followup. I'll probably still use the initrd approach for now.

Jon.