On Mon, Jul 2, 2018 at 5:07 PM, <Mario.Limonciello@xxxxxxxx> wrote: >> >> OK, now the most important question, did you investigate "SMM >> >> Communication ACPI Table"? >> >> Can you utilize information in it? >> >> > Dell BIOS does not provide a "SMM Communication ACPI Table", just the EPS. It >> appears >> > that the "SMM Communication ACPI Table" is deprecated in the UEFI 2.7 spec. >> Also, the >> > dcdbas driver is for Dell systems only. >> >> > The EPS table isn't an ACPI table, >> > it's just a Dell-defined table. >> >> Hmm... It's either strange or has some background why is so. >> OK it has a note that there is no use case, but here it is! >> >> Mario, can we consider this as a BIOS bug which doesn't provide SMM >> Communication ACPI table? >> >> Can it be escalated on UEFI committee? > I don't believe SMM communication ACPI table has ever been implemented by Dell > on server or client BIOS. I do agree this table describes the behavior that DCDBAS driver > has used since before even UEFI BIOS pretty accurately. So, EPS table has been for ages in Dell machines? Can we consider it as a predecessor of that SMM communication ACPI table? > Stuart and I did discuss with server BIOS (who uses this EPS mechanism) to see if its possible > to move EPS to SMM communication ACPI table however since it's been deprecated by > UEFI 2.7 they weren't willing to adopt it. It's pity, but the motivation to deprecate is "lack of use" which is not true. That's why I would suggest to escalate this to UEFI committee. > Stuart, anything else you want to add here? Darren, what's your opinion about this? P.S. I'm not against this approach (just some technical comments I already shared), but on the other hand it would be nice to have undo that deprecation and follow the standard in new firmwares. Would you agree? -- With Best Regards, Andy Shevchenko
