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authorOctavian Purdila <octavian.purdila@intel.com>2016-07-08 19:13:14 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-07-08 21:52:36 +0200
commit612bd01fc6e04c3ce9eb59587b4a7e4ebd6aff35 (patch)
tree00b1df2c43e46b3a7f8dd47cb954b077e19d772e /Documentation/acpi
parent0bf54fcd95042bd178cb25368422cf4474fc8492 (diff)
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ACPI: add support for loading SSDTs via configfs
New tables can be loaded by creating directories under /config/table/ and writing the AML code into the aml table attribute. Various table attributes will be readable once the table is successfully loaded. Unloading tables is not supported at the moment, but it can be easily implemented once ACPI loading functions provide a table handle to be used for unloading. Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/acpi')
-rw-r--r--Documentation/acpi/ssdt-overlays.txt14
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/acpi/ssdt-overlays.txt b/Documentation/acpi/ssdt-overlays.txt
index c4b57badd0b7..5ae13f161ea2 100644
--- a/Documentation/acpi/ssdt-overlays.txt
+++ b/Documentation/acpi/ssdt-overlays.txt
@@ -156,3 +156,17 @@ tmp=$(mktemp)
/bin/echo -ne "\007\000\000\000" | cat - $filename > $tmp
dd if=$tmp of="$EFIVARFS/$name-$guid" bs=$(stat -c %s $tmp)
rm $tmp
+
+== Loading ACPI SSDTs from configfs ==
+
+This option allows loading of user defined SSDTs from userspace via the configfs
+interface. The CONFIG_ACPI_CONFIGFS option must be select and configfs must be
+mounted. In the following examples, we assume that configfs has been mounted in
+/config.
+
+New tables can be loading by creating new directories in /config/acpi/table/ and
+writing the SSDT aml code in the aml attribute:
+
+cd /config/acpi/table
+mkdir my_ssdt
+cat ~/ssdt.aml > my_ssdt/aml