1 files changed, 20 insertions, 0 deletions
diff --git a/sys/dev/acpica/Osd/OsdTable.c b/sys/dev/acpica/Osd/OsdTable.c
index 58c01cd..f24c5ea 100644
--- a/sys/dev/acpica/Osd/OsdTable.c
+++ b/sys/dev/acpica/Osd/OsdTable.c
@@ -38,6 +38,26 @@
 #undef _COMPONENT
 #define _COMPONENT      ACPI_TABLES
 
+static char acpi_os_name[128];
+
+ACPI_STATUS
+AcpiOsPredefinedOverride (
+    const ACPI_PREDEFINED_NAMES *InitVal,
+    ACPI_STRING                 *NewVal)
+{
+    if (InitVal == NULL || NewVal == NULL)
+        return(AE_BAD_PARAMETER);
+
+    *NewVal = NULL;
+    if (strncmp(InitVal->Name, "_OS_", 4) == 0 &&
+      getenv_string("hw.acpi.os_name", acpi_os_name, sizeof(acpi_os_name))) {
+        printf("ACPI: Overriding _OS definition with \"%s\"\n", acpi_os_name);
+        *NewVal = acpi_os_name;
+    }
+
+    return(AE_OK);
+}
+
 ACPI_STATUS
 AcpiOsTableOverride (
     ACPI_TABLE_HEADER       *ExistingTable,