Re: [Fwd: Overriding ACPI tables]

Quoted 11 lines · Thomas Renninger

Peter: You wrote the syslinux stuff, right? What kind of luck is that :) There currently is a discussion about being able to override ACPI tables via initrd. The discussion is a bit stuck because the data is needed earlier than initrd is unpacked and the hacks to make it work are not accepted by Linus. I thought about adding another binary image to i386 boot protocol, similar to initrd= which contains data for very early kernel boot initialization, but this would be a heavy hammer (but IMO still better than only do it for kexec, another suggestion...) , I better open a separate thread or pre-ask privately whether this makes sense at all. It would be great if you could advise and possibly help to convince so that we finally may find a solution accepted mainline.

We're putting in a mechanism for pushing larger tables already; we need it for other things (in particular, the zones for E820 and EDD in the boot_info_table are simply not big enough.) That gives a generic mechanism for sending arbitrary-sized binary images to the kernel. That would be the mechanism to use.

I believe it's in upstream as this merge window; it's definitely in x86.git already.

Hi Peter,

Thank you for the pointer. You are talking about setup_data, right? I'll try to use it for reading the DSDT table. I have a couple of questions though:
* I can find reference of it only in setup_64.c, is it planned to add support also for 32bit? (That's a must for me)
* From inside the kernel, all I have to do is to add a hook inside parse_setup_data(), allocate memory and I'll be able to copy the data into this safe place, right?
* Is there any bootloader which already has support for this extension?
By chance, would you have a patch for grub?