From ca78bcd73b8d97228aa3a46d4cf9eac2a5c515cd Mon Sep 17 00:00:00 2001
From: Takanori Watanabe <takawata@FreeBSD.org>
Date: Fri, 6 Sep 2019 10:12:05 +0000
Subject: [PATCH] Add embedded Managed Object Format blob access to
 acpi_wmi(4). This blob is can be converted to human readable form by bmfdec.
 (http://github.com/pali/bmfdec)

Differential Revision:	https://reviews.freebsd.org/D21529
---
 share/man/man4/acpi_wmi.4       | 28 +++++++++++++++++++++++++++-
 sys/dev/acpi_support/acpi_wmi.c | 27 +++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/share/man/man4/acpi_wmi.4 b/share/man/man4/acpi_wmi.4
index 1eba57553fa9..b6bf0da4f250 100644
--- a/share/man/man4/acpi_wmi.4
+++ b/share/man/man4/acpi_wmi.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 22, 2011
+.Dd Sep 5, 2019
 .Dt ACPI_WMI 4
 .Os
 .Sh NAME
@@ -56,6 +56,15 @@ information about GUIDs found in the system.
 .It Pa /dev/wmistat%d
 WMI status device.
 .El
+.Sh SYSCTLS
+The following sysctl node is currently implemented:
+.Bl -tag 
+.It Va dev.acpi_wmi.%d.bmof
+Managed Object Format (MOF) blob.
+You can obtain human readable output by bmf2mof in bmfdec tool.
+(https://github.com/pali/bmfdec)
+.El
+
 .Sh EXAMPLES
 .Bd -literal
 # cat /dev/wmistat0
@@ -72,6 +81,20 @@ GUID                                  INST EXPE METH STR EVENT OID
 {8232DE3D-663D-4327-A8F4-E293ADB9BF05}   0 NO   NO   NO  NO    BG
 {8F1F6436-9F42-42C8-BADC-0E9424F20C9A}   0 NO   NO   NO  NO    BH
 {8F1F6435-9F42-42C8-BADC-0E9424F20C9A}   0 NO   NO   NO  NO    BI
+# sysctl -b dev.acpi_wmi.0.bmof |bmf2mof
+[abstract]
+class Lenovo_BIOSElement {
+};
+
+[WMI, Dynamic, Provider("WMIProv"), WmiExpense(1), Description("Bios Setting"),
+GUID("{51F5230E-9677-46cd-A1CF-C0B23EE34DB7}"), Locale("MS\\0x409")]
+class Lenovo_BiosSetting : Lenovo_BiosElement {
+  [key, read] String InstanceName;
+    [read] Boolean Active;
+      [WmiDataId(1), Description("BIOS setting")] String CurrentSetting;
+      };
+   ...
+
 .Ed
 .Sh SEE ALSO
 .Xr acpi 4
@@ -92,5 +115,8 @@ Work has been inspired by the Linux acpi-wmi driver written by Carlos Corbacho.
 See http://www.microsoft.com/whdc/system/pnppwr/wmi/wmi-acpi.mspx for
 the specification of ACPI-WMI.
 .Pp
+MOF part has been inspired by the Linux wmi-bmof driver
+written by Andy Lutomirski.
+.Pp
 This manual page was written by
 .An Michael Gmelin Aq Mt freebsd@grem.de .
diff --git a/sys/dev/acpi_support/acpi_wmi.c b/sys/dev/acpi_support/acpi_wmi.c
index bda7137881a7..c614be55ad74 100644
--- a/sys/dev/acpi_support/acpi_wmi.c
+++ b/sys/dev/acpi_support/acpi_wmi.c
@@ -62,6 +62,7 @@ ACPI_MODULE_NAME("ACPI_WMI");
 #define ACPI_WMI_REGFLAG_METHOD		0x2	/* GUID flag: Method call */
 #define ACPI_WMI_REGFLAG_STRING		0x4	/* GUID flag: String */
 #define ACPI_WMI_REGFLAG_EVENT		0x8	/* GUID flag: Event */
+#define ACPI_WMI_BMOF_UUID "05901221-D566-11D1-B2F0-00A0C9062910"
 
 /*
  * acpi_wmi driver private structure
@@ -74,6 +75,8 @@ struct acpi_wmi_softc {
 	struct sbuf	wmistat_sbuf;	/* sbuf for /dev/wmistat output */
 	pid_t		wmistat_open_pid; /* pid operating on /dev/wmistat */
 	int		wmistat_bufptr;	/* /dev/wmistat ptr to buffer position */
+	char 	        *mofbuf;
+	
 	TAILQ_HEAD(wmi_info_list_head, wmi_info) wmi_info_list;
 };
 
@@ -274,6 +277,29 @@ acpi_wmi_attach(device_t dev)
 	}
 	ACPI_SERIAL_END(acpi_wmi);
 
+	if (acpi_wmi_provides_guid_string_method(dev, ACPI_WMI_BMOF_UUID)) {
+		ACPI_BUFFER out = { ACPI_ALLOCATE_BUFFER, NULL };
+		ACPI_OBJECT *obj;
+
+		device_printf(dev, "Embedded MOF found\n");
+		status = acpi_wmi_get_block_method(dev,  ACPI_WMI_BMOF_UUID,
+		    0, &out);
+		if (ACPI_SUCCESS(status)) {
+			obj = out.Pointer;
+			if (obj && obj->Type == ACPI_TYPE_BUFFER) {
+				SYSCTL_ADD_OPAQUE(device_get_sysctl_ctx(dev),
+				    SYSCTL_CHILDREN(
+				        device_get_sysctl_tree(dev)),
+				    OID_AUTO, "bmof", 
+				    CTLFLAG_RD | CTLFLAG_MPSAFE,
+				    obj->Buffer.Pointer,
+				    obj->Buffer.Length,
+				    "A", "MOF Blob");
+			}
+		}
+		sc->mofbuf = out.Pointer;
+	}
+		
 	if (ret == 0) {
 		bus_generic_probe(dev);
 		ret = bus_generic_attach(dev);
@@ -321,6 +347,7 @@ acpi_wmi_detach(device_t dev)
 		sc->wmistat_open_pid = 0;
 		destroy_dev(sc->wmistat_dev_t);
 		ret = 0;
+		AcpiOsFree(sc->mofbuf);
 	}
 	ACPI_SERIAL_END(acpi_wmi);