Caution
this is really sketchy. only install it if you know what you are doing. it was only tested on my exact hw and install. so be carefull when installing. the consquences can reach from not having audio in your os to bricking something. NEVER INSTALL this on a laptop where security is essential since you need to disable secureboot for the module to load.
Grubsound is the ultimate larp grub module. Its only purpose is playing a wav file while booting. Primarily used for ricing your thinkpad. Best served with a cool looking grub theme. Adjust the sound to taste.
On a serious note it is a from scratch async intal hda driver as a grub module. It resets the controller, sets up corb and cirb, discovers codecs wiget graph, routes a dac to speaker pins, and streams the samples over cyclic bdl dma. Its written for and only tested on MY ThinkPad X1 Carbon Gen 11 (Realtek ALC287, Intel 8086:51ca). It will still probably work on other Itel HDA hardware. If you test it on your HW and it works make sure to create a issue.
make # build module + test image (fetches grub on first run)
make && sudo make try # boot it once via one shot entry... changes noting on disk
make && sudo make install # install it into running grub
sudo make uninstall # revert
secure boot needs to be off... the module is unsigned and secure boot grub refuses to load it. you can probably sign it and enroll your keys on your device. but if you really need secure boot you should pretty much just not install it.
try puts a self contained efi image on the efi system partition and arms a one shot uefi entry
use make GRUB_SRC=/path/to/grub2-src to use your own grub source tree instead of downloading it
sudo make install SOUND=sound/chime.wav TIMEOUT=6 VOLUME=70
the audio file needs to be 16 bit pcm mono or stereo 44.1 or 48khz. volume 100 = 0dB on the codecs amp. 50 about -6dB. and timeout is the timeout before your os boots automatically
when you press s while booting the sound will be silent. enther the grub console and run hda_status to print debug info. install creates a grub backup under /boot/grub/grubsound-backup
GPLv3+ as required for a grub module. full text in LICENSE