Linux requires UEFI support to be enabled on ARM64 devices. While many
ARM64 devices lack ACPI, the writing seems to be on the wall of UEFI/ACPI
potentially taking over. Some common devices may require ACPI table
support to boot.
For devices which can boot in either mode, continue defaulting to
device-tree. Add warnings about using ACPI advising users of present
situation.
Signed-off-by: Elliott Mitchell <ehem+...@m5p.com>
---
Okay, hopefully this is okay. Warning in Kconfig, warning on boot.
Perhaps "default y if ARM_64" is redundant, yet if someone tries to make
it possible to boot aarch32 on a ACPI machine...
I also want a date in the message. Theory is this won't be there
forever, so a date is essential.
---
xen/arch/arm/Kconfig | 7 ++++++-
xen/arch/arm/acpi/boot.c | 9 +++++++++
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 2777388265..29624d03fa 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -32,13 +32,18 @@ menu "Architecture Features"
source "arch/Kconfig"
config ACPI
- bool "ACPI (Advanced Configuration and Power Interface) Support" if
EXPERT
+ bool "ACPI (Advanced Configuration and Power Interface) Support"
depends on ARM_64
+ default y if ARM_64
---help---
Advanced Configuration and Power Interface (ACPI) support for Xen is
an alternative to device tree on ARM64.
+ Note this is presently EXPERIMENTAL. If a given device has both
+ device-tree and ACPI support, it is presently (October 2020)
+ recommended to boot using the device-tree.
+
config GICV3
bool "GICv3 driver"
depends on ARM_64 && !NEW_VGIC
diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
index 30e4bd1bc5..c0e8f85325 100644
--- a/xen/arch/arm/acpi/boot.c
+++ b/xen/arch/arm/acpi/boot.c
@@ -254,6 +254,15 @@ int __init acpi_boot_table_init(void)
dt_scan_depth1_nodes, NULL) )
goto disable;
+ printk("\n"
+"*************************************************************************\n"
+"* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING *\n"
+"* *\n"
+"* Xen-ARM ACPI support is EXPERIMENTAL. It is presently (October 2020) *\n"
+"* recommended you boot your system in device-tree mode if you can. *\n"
+"*************************************************************************\n"
+ "\n");
+
/*
* ACPI is disabled at this point. Enable it in order to parse
* the ACPI tables.
--
2.20.1
--
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