Hi Elliot,
On 14/10/2020 02:37, Elliott Mitchell wrote:
On Tue, Oct 13, 2020 at 06:06:26PM -0700, Stefano Stabellini wrote:
On Mon, 12 Oct 2020, Elliott Mitchell wrote:
I'm on different hardware, but some folks have setup Tianocore for it.
According to Documentation/arm64/acpi_object_usage.rst,
"Required: DSDT, FADT, GTDT, MADT, MCFG, RSDP, SPCR, XSDT". Yet when
booting a Linux kernel directly on the hardware it lists APIC, BGRT,
CSRT, DSDT, DBG2, FACP, GTDT, PPTT, RSDP, and XSDT.
I don't know whether Linux's ACPI code omits mention of some required
tables and merely panics if they're absent. Yet I'm speculating the list
of required tables has shrunk, SPCR is no longer required, and the
documentation is out of date. Perhaps SPCR was required in early Linux
ACPI implementations, but more recent ones removed that requirement?
I have just checked and SPCR is still a mandatory table in the latest
SBBR specification. It is probably one of those cases where the firmware
claims to be SBBR compliant, but it is not, and it happens to work with
Linux.
Is meeting the SBBR specification supposed to be a requirement of running
Xen-ARM?
This is not my goal. We should try to get Xen running everywhere as long
as this doesn't require a lot of extra code. IOW, don't ask me to
review/accept a port of Xen to RPI3 ;).
Cheers,
--
Julien Grall
