Lai (Lux ACPI Implementation): AML for Lux, a Unix-like OS

Lux is a new Unix-like operating written for the PC, aiming for high performance with minimal requirements. Lai, the Lux ACPI Implementation, is an implementation of ACPI’s Machine Language (AML) written for use with lux, but with portability in mind. As such, lai is portable and OS-independent. It depends on a few OS-specific functions, and so a small layer is written for each OS lai is to be used with, and this requires no changes to the core code of lai.




AHCI BIOS Security Extension

This software is useful if:
* you have a (probably self-encrypting) hard disk / solid state drive that supports the (S)ATA SECURITY command set

* you want to boot from this drive.
* your motherboard’s BIOS does not support asking the user for a hard disk password at startup
* you don’t want to buy a new motherboard.
* the hard disk controller of your motherboard supports AHCI.




Linux ACPI Time and Alarm Device (TAD) driver

Rafael J. Wysocki of Intel submitted a patch to Linux ACPI for a ACPI Time and Alarm Device (TAD) driver:

Introduce a driver for the ACPI Time and Alarm Device (TAD) based on Section 9.18 of ACPI 6.2. This driver only supports the system wakeup capabilities of the TAD which are mandatory. Support for the RTC capabilities of the TAD will be added to it in the future. This driver is entirely sysfs-based. It provides attributes (under the TAD platform device) to allow user space to manage the AC and DC wakeup timers of the TAD: set and read their values, set and check their expire timer wake policies, check and clear their status and check the capabilities of the TAD reported by AML. The DC timer attributes are only present if the TAD supports a separate DC alarm timer. The wakeup events handling and power management of the TAD is expected to be taken care of by the ACPI PM domain attached to its platform device.

The ACPI Time and Alarm (TAD) device is an alternative to the Real Time Clock (RTC). Its wake timers allow the system to transition from the S3 (or optionally S4/S5) state to S0 state after a time period elapses. In comparison with the RTC Alarm, the TAD provides a larger scale of flexibility in the wake timers. The time capabilities of the TAD maintain the time of day information across platform power transitions, and keep track of time even when the platform is turned off.

More info: linux-acpi list archives, http://vger.kernel.org/majordomo-info.html




ARM Dynamic Tables Framework

ARM has submitted a patch to UEFI’s Tianocore which adds a “Dynamic Tables” framework that abstracts ACPI amongst other things…  Readme excerpt of patch below:

This patch introduces a branch for implementing Dynamic Tables Framework.

To reduce the amount of effort required in porting firmware to new platforms, we propose this “Dynamic Tables” framework. The aim is to provide an example implementation capable of generating the firmware tables from an external source. This is potentially a management node, either local or remote, or, where suitable, a file that might be generated from the system construction. This initial “proof of concept” release does not fully implement that – the configuration is held in local UEFI modules.

The dynamic tables framework is designed to generate standardised firmware tables that describe the hardware information at run-time. A goal of standardised firmware is to have a common firmware for a platform capable of booting both Windows and Linux operating systems.

Traditionally the firmware tables are handcrafted using ACPI Source Language (ASL), Table Definition Language (TDL) and C-code. This approach can be error prone and involves time consuming debugging. In addition, it may be desirable to configure platform hardware at runtime such as: configuring the number of cores available for use by the OS, or turning SoC features ON or OFF.

The dynamic tables framework simplifies this by providing a set of standard table generators, that are implemented as libraries. These generators query a platform specific component, the ‘Configuration Manager’, to collate the information required for generating the tables at run-time.

The framework also provides the ability to implement custom/OEM generators; thereby facilitating support for custom tables. The custom generators can also utilize the existing standard generators and override any functionality if needed.

The framework currently implements a set of standard ACPI table generators for ARM architecture, that can generate Server Base Boot Requirement (SBBR) compliant tables. Although, the set of standard generators implement the functionality required for ARM architecture; the framework is extensible, and support for other architectures can be added easily.

The framework currently supports the following table generators for ARM:
* DBG2 – Debug Port Table 2
* DSDT – Differentiated system description table. This is essentially a RAW table generator.
* FADT – Fixed ACPI Description Table
* GTDT – Generic Timer Description Table
* IORT – IO Remapping Table
* MADT – Multiple APIC Description Table
* MCFG – PCI Express memory mapped configuration space base address Description Table
* SPCR – Serial Port Console Redirection Table
* SSDT – Secondary System Description Table. This is essentially a RAW table generator.

[…]Please create a branch called ‘dynamictables’ in edk2-staging.[…]

More info: see the “[PATCH] Branch to implement Dynamic Tables Framework” thread on the edk2-devel list by Sami Mujawar. And look for above branch to be created.

Hmm, it appears the links to the archives on the URL provided in the mailing list posts is not valid:

V1 from Oct2017:



Firmware Test Suite 18.02.00 is released

New Features:
* ACPICA: Update to version 20180209
* uefirtvariable: add test for EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS attribute

See full announcement for list of bugfixes.

In related news, LUV has picked up the latest FWTS.



DPTFExtract – Linux DPTF Extract Utility

This is a companion tool to Linux Thermal Daemon (thermald). This tool tries to reuse some of the tables used by “Intel ® Dynamic Platform and Thermal Framework (Intel® DPTF)” by converting to the thermal_conf.xml format used by thermald.