On Thu, 21 Jul 2022 at 19:13, Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > > On 7/19/22 17:26, Marc Orr wrote: > > - Dave's suggestion to "2. Boot some intermediate thing like a > > bootloader that does acceptance ..." is pretty clever! So if upstream > > thinks this FW-kernel negotiation is not a good direction, maybe we > > (Google) can pursue this idea to avoid introducing yet another tag on > > our images. > > I'm obviously speaking only for myself here and not for "upstream" as a > whole, but I clearly don't like the FW/kernel negotiation thing. It's a > permanent pain in our necks to solve a very temporary problem. EFI is basically our existing embodiment of this fw/kernel negotiation thing, and iff we need it, I have no objection to using it for this purpose, i.e., to allow the firmware to infer whether or not it should accept all available memory on behalf of the OS before exiting boot services. But if we don't need this, even better. What I strongly object to is inventing a new bespoke way for the firmware to make inferences about the capabilities of the image by inspecting fields in the file representation of the image (which is not guaranteed by EFI to be identical to its in-memory representation, as, e.g., the PE/COFF header could be omitted by a loader without violating the spec) As for the intermediate thing: yes, that would be a valuable thing to have in OVMF (and I will gladly take EDK2 patches that implement this). However, I'm not sure how you decide whether or not this thing should be active or not, doesn't that just move the problem around?
