[ACPI] allow config to specify custom DSDT (Ulf Dambacher)

drivers/acpi/Kconfig

@@ -204,6 +204,23 @@ config ACPI_TOSHIBA
 	  If you have a legacy free Toshiba laptop (such as the Libretto L1
 	  series), say Y.
 
+config ACPI_CUSTOM_DSDT
+	bool "Include Custom DSDT"
+	depends on X86
+	depends on ACPI_INTERPRETER
+	default n 
+	help
+	  Thist option is to load a custom ACPI DSDT
+	  If you don't know what that is, say N.
+
+config ACPI_CUSTOM_DSDT_FILE
+	string "Custom DSDT Table file to include"
+	depends on ACPI_CUSTOM_DSDT
+	default ""
+	help
+	  Enter the full path name to the file wich includes the AmlCode declaration.
+
+
 config ACPI_DEBUG
 	bool "Debug Statements"
 	depends on ACPI_INTERPRETER

drivers/acpi/osl.c

@@ -55,6 +55,9 @@ struct acpi_os_dpc
     void		    *context;
 };
 
+#ifdef CONFIG_ACPI_CUSTOM_DSDT
+#include CONFIG_ACPI_CUSTOM_DSDT_FILE
+#endif
 
 #ifdef ENABLE_DEBUGGER
 #include <linux/kdb.h>
@@ -241,7 +244,14 @@ acpi_os_table_override (struct acpi_table_header *existing_table,
 	if (!existing_table || !new_table)
 		return AE_BAD_PARAMETER;
 
+#ifdef CONFIG_ACPI_CUSTOM_DSDT
+	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
+		*new_table = (struct acpi_table_header*)AmlCode;
+	else
+		*new_table = NULL;
+#else
 	*new_table = NULL;
+#endif
 	return AE_OK;
 }