Load custom ACPI tables

custom_acpi_tables.md

ACPI DSDT/SSDT patching

These instructions are meant for a system with EFI, systemd-boot and deb based packages. Adjust them to your needs.

Reference: https://www.kernel.org/doc/Documentation/acpi/initrd_table_override.txt

See also https://github.com/lbschenkel/acer-sf314_43-acpi-patch

ACPICA tools: https://acpica.org/downloads

sudo apt install acpica-tools

Option 1: DSDT, extract and modify the tables

Extract the acpi tables

mkdir acpi && cd acpi
sudo acpidump -b

Disassemble the tables

iasl -d dsdt.dat

Modify or patch the tables

vim dsdt.dsl

Assemble the custom tables

iasl -sa dsdt.dsl

Generate the cpio file for initrd

cd ..
mkdir -p kernel/firmware/acpi
cp acpi/dsdt.aml kernel/firmware/acpi/
find kernel | cpio -H newc --create > patched_acpi_tables.cpio

Grub does not require a cpio file, you can directly provide the dsl file.

Option 2: SSDT, create the tables

SSDT tables add missing features to the existing ACPI, without requiring disassembling. They are created using the same tools and procedure.

Assemble the custom tables

iasl -sa ssdt.dsl

Generate the cpio file for initrd

cd ..
mkdir -p kernel/firmware/acpi
cp acpi/ssdt.aml kernel/firmware/acpi/
find kernel | cpio -H newc --create > patched_acpi_tables.cpio

Install the tables (systemd-boot)

Copy the cpio file with the custom tables where it can be addressed by the EFI boot

sudo mkdir /boot/efi/EFI/acpi
sudo cp patched_acpi_tables.cpio /boot/efi/EFI/acpi/

Edit the entry sudo vim /boot/efi/loader/entries/Pop_OS-current.conf

linux /EFI/...
initrd /EFI/acpi/patched_acpi_tables.cpio
initrd /EFI/Pop_OS-.../initrd.img
options ...

Anyone having done this patch notice that when the system volume is low the sound is more bass than treble and the reverse when the volume is high? Somewhere around 75% sounds pretty good. Wondering if it's just an issue on my end.

Let's go. My sound works perfectly.
For NixOS people, I made a module that is very easy to integrate into your NixOS configuration :
https://github.com/mrnossiom/dotfiles/blob/nixos/modules/nixos/asus-zenbook-ux3402za-sound.nix

Let's go. My sound works perfectly. For NixOS people, I made a module that is very easy to integrate into your NixOS configuration : https://github.com/mrnossiom/dotfiles/blob/nixos/modules/nixos/asus-zenbook-ux3402za-sound.nix

THANK YOU! I couldn't figure out how to nixify the instructions to work with systemd-boot, but your config just worked!