On 6 April 2018 at 16:14, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > On 6 April 2018 at 16:08, Luis R. Rodriguez <mcgrof@xxxxxxxxxx> wrote: >> On Thu, Apr 05, 2018 at 07:43:49AM +0200, Lukas Wunner wrote: >>> On Wed, Apr 04, 2018 at 01:18:36PM -0400, Peter Jones wrote: >>> > > On Tue, Apr 03, 2018 at 08:07:11PM +0200, Lukas Wunner wrote: >>> > > > * Add the EFI Firmware Volume Protocol to include/linux/efi.h: >>> > > > https://www.intel.com/content/dam/doc/reference-guide/efi-firmware-file-volume-specification.pdf >>> > > > >>> > > > * Amend arch/x86/boot/compressed/eboot.c to read the files with the >>> > > > GUIDs you're interested in into memory and pass the files to the >>> > > > kernel as setup_data payloads. >>> > >>> > To be honest, I'm a bit skeptical about the firmware volume approach. >>> > Tools like UEFITool[0] and uefi-firmware-parser[1] have existed for >>> > years, still don't seem to reliably parse firmware images I see in the >>> > wild, and have a fairly regular need for fixes. These are tools >>> > maintained by smart people who are making a real effort, and it still >>> > looks pretty hard to do a good job that applies across a lot of >>> > platforms. >>> > >>> > So I'd rather use Hans's existing patches, at least for now, and if >>> > someone is interested in hacking on making an efi firmware volume parser >>> > for the kernel, switch them to that when such a thing is ready. >>> >>> Hello? As I've written in the above-quoted e-mail the kernel should >>> read the files using EFI_FIRMWARE_VOLUME_PROTOCOL.ReadFile(). >>> >>> *Not* by parsing the firmware volume! >>> >>> Parsing the firmware volume is only necessary to find out the GUIDs >>> of the files you're looking for. You only do that *once*. >> >> How do you get the GUIDs for each driver BTW? >> >> Hans, I do believe we should *try* this approach at the very least. >> >> Why not? >> >> Otherwise it would be wise to provide a technical reason for why >> we'd choose one custom mechanism which would only serve a few tablets >> over a mechanism which could serve more devices. >> > > Because EFI_FIRMWARE_VOLUME_PROTOCOL is not part of the UEFI spec but > of the PI spec, and so we will be adding dependencies on > implementation details of the firmware. I am aware we may already have > done so for the Apple properties support ... or maybe not: I thought Lukas alluded to that in this thread, but I can't actually find any traces of that in the code so I must have misunderstood. , but I think it makes sense > to make an exception there, given that Mac UEFI firmware is 'special' > already. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
