Version 20131218

18 December 2013. Summary of changes for version 20131218:

This release is available at

Global note: The ACPI 5.0A specification was released this month. There are no changes needed for ACPICA since this release of ACPI is an errata/clarification release.

1) ACPICA kernel-resident subsystem:

Added validation of the XSDT root table if it is present. Some older platforms contain an XSDT that is ill-formed or otherwise invalid (such as containing some or all entries that are NULL pointers). This change adds a new function to validate the XSDT before actually using it. If the XSDT is found to be invalid, ACPICA will now automatically fall back to using the RSDT instead. Original implementation by Zhao Yakui. Ported to ACPICA and enhanced by Lv Zheng and Bob Moore.

Added a runtime option to ignore the XSDT and force the use of the RSDT. This change adds a runtime option that will force ACPICA to use the RSDT instead of the XSDT (AcpiGbl_DoNotUseXsdt). Although the ACPI spec requires that an XSDT be used instead of the RSDT, the XSDT has been found to be corrupt or ill-formed on some machines. Lv Zheng.

Added a runtime option to favor 32-bit FADT register addresses over the 64-bit addresses. This change adds an option to favor 32-bit FADT addresses when there is a conflict between the 32-bit and 64-bit versions of the same register. The default behavior is to use the 64-bit version in accordance with the ACPI specification. This can now be overridden via the AcpiGbl_Use32BitFadtAddresses flag. ACPICA BZ 885. Lv Zheng.

During the change above, the internal "Convert FADT" and "Verify FADT" functions have been merged to simplify the code, making it easier to understand and maintain. ACPICA BZ 933.

Improve exception reporting and handling for GPE block installation. Return an actual status from AcpiEvGetGpeXruptBlock and don't clobber the status when exiting AcpiEvInstallGpeBlock. ACPICA BZ 1019.

Added helper macros to extract bus/segment numbers from the HEST table. This change adds two macros to extract the encoded bus and segment numbers from the HEST Bus field - ACPI_HEST_BUS and ACPI_HEST_SEGMENT. Betty Dall

Removed the unused ACPI_FREE_BUFFER macro. This macro is no longer used by ACPICA. It is not a public macro, so it should have no effect on existing OSV code. Lv Zheng.

Example Code and Data Size: These are the sizes for the OS-independent acpica.lib produced by the Microsoft Visual C++ 9.0 32-bit compiler. The debug version of the code includes the debug output trace mechanism and has a much larger code and data size.

Current Release:
Non-Debug Version: 96.1K Code, 27.0K Data, 123.1K Total
Debug Version: 185.6K Code, 77.3K Data, 262.9K Total
Previous Release:
Non-Debug Version: 95.9K Code, 27.0K Data, 122.9K Total
Debug Version: 185.1K Code, 77.2K Data, 262.3K Total

2) iASL Compiler/Disassembler and Tools:

Disassembler: Improved pathname support for emitted External() statements. This change adds full pathname support for external names that have been resolved internally by the inclusion of additional ACPI tables (via the iASL -e option). Without this change, the disassembler can emit multiple externals for the same object, or it become confused when the Scope() operator is used on an external object. Overall, greatly improves the ability to actually recompile the emitted ASL code when objects a referenced across multiple ACPI tables. Reported by Michael Tsirkin (

Tests/ASLTS: Updated functional control suite to execute with no errors. David Box. Fixed several errors related to the testing of the interpreter slack mode. Lv Zheng.

iASL: Added support to detect names that are declared within a control method, but are unused (these are temporary names that are only valid during the time the method is executing). A remark is issued for these cases. ACPICA BZ 1022.

iASL: Added full support for the DBG2 table. Adds full disassembler, table compiler, and template generator support for the DBG2 table (Debug Port 2 table).

iASL: Added full support for the PCCT table, update the table definition. Updates the PCCT table definition in the actbl3.h header and adds table compiler and template generator support.

iASL: Added an option to emit only error messages (no warnings/remarks). The -ve option will enable only error messages, warnings and remarks are suppressed. This can simplify debugging when only the errors are important, such as when an ACPI table is disassembled and there are many warnings and remarks -- but only the actual errors are of real interest.

Example ACPICA code (source/tools/examples): Updated the example code so that it builds to an actual working program, not just example code. Added ACPI tables and execution of an example control method in the DSDT. Added makefile support for Unix generation.

18 December, 2013