[GSoC WIP] liblua: ACPICA Lua bindings #1819

kpowkitty · 2025-08-21T08:54:20Z

GSoC WIP under @bsdimp

Follows #1843 and #1818 in that order.

Description:
Lua bindings for ACPICA in loader to provide an interface for users to
print the ACPI namespace, attach/detach/get data off of device nodes,
and evaluate objects.

Please see man page commit for acpi.lua for more information

lacpi_object.c

Module for evaluating ACPI objects.
This module also provides the ability to convert pathnames into
their opaque pointer using get_handle.

lacpi_walk.c

Allows users to walk the namespace in the loader.
Currently works by walking the entire namespace and
storing each node in a 2D table of nodes.

Use case:
nodes = lacpi.walk.namespace()
for _, node in ipairs(nodes) do
print(node.path, node.lvl, node.hid, node.uid)
end

Future plans:
(1) better representation of nodes for the user when printed
(2) strategy patterns for how to receive the namespace

lacpi_data.c

Allows a user to post ACPI_OBJECTs onto namespace nodes.
See actypes.h for all possible ACPI_OBJECTs.

Sponsored by: Google Summer of Code 2025
Signed-off-by: Kayla Powell (AKA Kat) [email protected]

stand/efi/loader/Makefile

stand/liblua/Makefile

stand/liblua/acpi/lacpi.h

stand/liblua/acpi/lacpi_object.c

stand/efi/loader/Makefile

stand/liblua/lutils.c

github-actions · 2025-09-05T23:31:52Z

Thank you for taking the time to contribute to FreeBSD!
There is an issue that needs to be fixed:

Missing Signed-off-by lines^{b5d71ae, 1a20a35, b8fb47d, e90f340, a53ebc2}

Please review CONTRIBUTING.md, then update and push your branch again.

Description: Continuation of freebsd#1819. [WIP] Needs to be tested.

Description: Refactored ACPICA for partial initialization in the loader. This work is the final preface for Lua bindings. Work on this commit involves: Subset ACPICA for loader land: For our Lua bindings, we need to be able to walk the ACPI namespace and evaluate objects. To do so, we need AcpiInitializeSubsystem, AcpiInitializeTables, AcpiEnableSubsystem, and AcpiLoadTables. Notes: -acpi_detect() moved into libacpi. -Libacpi conditionally compiles ACPICA and glue code on amd64. (arm64 will be addressed in a future update) -AcpiEnableSubsystem is initialized in reduced hardware mode, but with events enabled. This is so that we do not need to pull in all of ACPI_HARDWARE, but can evaluate objects. -Stubbed out Osd functions required for this limited initialization. -Conditionally exclude functions to make a minimal subset designed around loader's/lua binding's needs: --Exclude AcpiInitializeObjects, as we do not need this for walking the namespace and evaluating objects. (utxfinit.c) --Exclude notify handlers or fixed event handlers. (evxface.c) --Stub out print functions, as the loader does not have standard output. (osunixxf.c) --Stub out AcpiOsSleep and AcpiOsGetTimer, as the loader is not multi-threaded and does not implement timers. (osunixxf.c)

These bindings have two conditions: (1) Must be built on `amd64` (2) Must be building `loader_lua` If these conditions are met: - Add liblua as a subdir in EFI - Include liblua/acpi/include in loader/Makefile - Add set_lua_acpi_modules to the loader compile set - Add 'lacpi.h' to loader/main.c and reference the bindings

kpowkitty requested a review from bsdimp as a code owner August 21, 2025 08:54