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, 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
