ACPICA version 20100528 released

[Moore, Robert]

28 May 2010. Summary of changes for version 20100528:

This release is available at www.acpica.org/downloads

Note: The ACPI 4.0a specification was released on April 5, 2010 and is available at www.acpi.info. This is primarily an errata release.

1) ACPI CA Core Subsystem:

Undefined ACPI tables: We are looking for the definitions for the following ACPI tables that have been seen in the field: ATKG, IEIT, GSCI.

Implemented support to enable multi-byte transfers for Embedded Controller (EC) operation regions. Previously, the maximum data size passed to the EC operation region handler was a single byte. There are often EC Fields larger than one byte that need to be transferred, and it is useful for the EC driver to lock these as a single transaction. This change enables single transfers larger than 8 bits. This effectively changes the access to the EC space from ByteAcc to AnyAcc, and will probably require changes to the host OS Embedded Controller driver to enable 16/32/64/256-bit transfers in addition to 8-bit transfers. Alexey Starikovskiy, Lin Ming

Implemented a performance enhancement for namespace search and access. This change enhances the performance of namespace searches and walks by adding a backpointer to the parent in each namespace node. On large namespaces, this change can improve overall ACPI performance by up to 9X. Adding a pointer to each namespace node increases the overall size of the internal namespace by about 5%, since each namespace entry usually consists of both a namespace node and an ACPI operand object. However, this is the first growth of the namespace in ten years. ACPICA bugzilla 817. Alexey Starikovskiy.

Implemented a performance optimization that reduces the number of namespace walks. On control method exit, only walk the namespace if the method is known to have created namespace objects outside of its local scope. Previously, the entire namespace was traversed on each control method exit. This change can improve overall ACPI performance by up to 3X. Alexey Starikovskiy, Bob Moore.

Added support to truncate I/O addresses to 16 bits for Windows compatibility. Some ASL code has been seen in the field that inadvertently has bits set above bit 15. This feature is optional and is enabled if the BIOS requests any Windows OSI strings. It can also be enabled by the host OS. Matthew Garrett, Bob Moore.

Added support to limit the maximum time for the ASL Sleep() operator. To prevent accidental deep sleeps, limit the maximum time that Sleep() will actually sleep. Configurable, the default maximum is two seconds. ACPICA bugzilla 854.

Added run-time validation support for the _WDG and_WED Microsoft predefined methods. These objects are defined by "Windows Instrumentation", and are not part of the ACPI spec. ACPICA BZ 860.

Expanded all statistic counters used during namespace and device initialization from 16 to 32 bits in order to support very large namespaces.

Replaced all instances of %d in printf format specifiers with %u since nearly all integers in ACPICA are unsigned.

Fixed the exception namestring for AE_WAKE_ONLY_GPE. Was incorrectly returned as AE_NO_HANDLER.

Example Code and Data Size: These are the sizes for the OS-independent acpica.lib produced by the Microsoft Visual C++ 6.0 32-bit compiler. The debug version of the code includes the debug output trace mechanism and has a much larger code and data size.

  Previous Release:
    Non-Debug Version:  88.4K Code, 18.8K Data, 107.2K Total
    Debug Version:     164.2K Code, 51.5K Data, 215.7K Total
  Current Release:
    Non-Debug Version:  88.3K Code, 18.8K Data, 107.1K Total
    Debug Version:     164.1K Code, 51.5K Data, 215.6K Total

2) iASL Compiler/Disassembler and Tools:

iASL: Added compiler support for the _WDG and_WED Microsoft predefined methods. These objects are defined by "Windows Instrumentation", and are not part of the ACPI spec. ACPICA BZ 860.

AcpiExec: added option to disable the memory tracking mechanism. The -dt option will disable the tracking mechanism, which improves performance considerably.

AcpiExec: Restructured the command line options into -d (disable) and -e (enable) options.