cbrune/apd-tools

ACPI Platform Description Tools

apd-tools (ACPI Platform Description)

Overview

apd-tools is a set of tools to help encode network switch platform details using ACPI. The project consists of a set of guidelines and tools to help developers create and evaluate ACPI table modifications on network switch platforms.

Quick Start

See the apd-tools Wiki for complete getting started documentation.

Prerequisites

1. The iasl compiler from ACPICA
2. An OS with APD kernel changes

ACPI Table Override on Cumulus Linux

Development of ACPI tables on Linux is typically done by overriding the BIOS tables during early kernel initialization. The mechanism is documented in the Linux kernel tree. Cumulus Linux provides convienence script that to automate those instructions. To override the built-in ACPI tables, place a file for each table in:

SLOT=1
/boot/acpi-slot-$SLOT/kernel/firmware/acpi

then run update-dsdt

For example, to replace the DSDT for the Cumulus Linux image in install slot 1:

mkdir -p /boot/acpi-slot-1/kernel/firmware/acpi
cp dsdt.aml /boot/acpi-slot-1/kernel/firmware/acpi
update-dsdt

This will create grub menu entries to boot Cumulus Linux with the updated DSDT.

Reboot and select the "ACPI override" grub menu option. It's a good idea to attempt the _PRT "hello world" example from initrd_table_override.txt to prove the mechanism is working.