configs: qemu: add config fragment for ACPI

Provide a configuration fragment to enable ACPI on QEMU.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

MAINTAINERS

@@ -53,6 +53,7 @@ Maintainers List (try to look for most precise areas first)
 ACPI:
 M:	Simon Glass <sjg@chromium.org>
 S:	Maintained
+F:	board/emulation/configs/acpi.config
 F:	cmd/acpi.c
 F:	lib/acpi/
 

board/emulation/configs/acpi.config

@@ -0,0 +1,3 @@
+CONFIG_CMD_QFW=y
+CONFIG_ACPI=y
+CONFIG_GENERATE_ACPI_TABLE=y

doc/board/emulation/acpi.rst

@@ -0,0 +1,23 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+ACPI on QEMU
+============
+
+QEMU can provide ACPI tables on ARM, RISC-V (since QEMU v8.0.0), and x86.
+
+The following U-Boot settings are needed for ACPI support::
+
+    CONFIG_CMD_QFW=y
+    CONFIG_ACPI=y
+    CONFIG_GENERATE_ACPI_TABLE=y
+
+On x86 these settings are already included in the defconfig files. ARM and
+RISC-V default to use device-trees.
+
+Instead of updating the configuration manually you can add the configuration
+fragment `acpi.config` to the make command for initializing the configuration.
+E.g.
+
+.. code-block:: bash
+
+    make qemu-riscv64_smode_defconfig acpi.config

doc/board/emulation/index.rst

@@ -6,6 +6,7 @@ Emulation
 .. toctree::
    :maxdepth: 1
 
+   acpi
    blkdev
    ../../usage/semihosting
    qemu-arm