On 7 December 2015 at 06:05, Mark Rutland mark.rutland@arm.com wrote:
Hi,
On Sun, Dec 13, 2015 at 03:47:12AM -0500, Jon Masters wrote:
Hi Folks,
Just a few notes that might be useful to someone else.
I mentioned before that we'll want to see ACPI_INITRD_TABLE_OVERRIDE support on arm64 in due course for use during bringup of new systems. It is commonly used on x86 to provide handy updated ACPI tables via a prepended initrd cpio that is attached to the regular initrd image, which is infinitely better than respinning firmware each time you want to provide updated tables (yes yes, we all know the "devicetree" directive in GRUB does this with DT and that's great and wonderful). I know that someone is working on it, but I had a need for an interim solution over the weekend for some hardware I am bringing up here.
Which table(s) are you trying to override?
It might be possible to have an EFI application prior to the kernel which override the relevant table, or you may be able to override the tables in the EFI stub. From the PoV of Linux proper, things would then be the same as a normal boot -- nothing special to be done.
If you're able to do this in a separate application prior to the stub (or even prior to the main bootloader), that same override should work for any OS.
grub2 already has a acpi module which should allow this.
Graeme