Serg Podtynnyi shtirlic

Index

Gummiboot
Silent Grub
Turn off Mitigations
Disable Watchdog
Kernel Parameters
Fstab Modification
Optimizing Boot
Fix bad font rendering
Getting rid of unnecessary packages

Here is the best setup (I think so :D) for K-series Keychron keyboards on Linux.

Note: many newer Keychron keyboards use QMK as firmware and most tips here do not apply to them. Maybe the ones related to Bluetooth can be useful, but everything related to Apple's keyboard module (hid_apple) on Linux, won't work. As far as I know, all QMK-based boards use the hid_generic module instead. Examples of QMK-based boards are: Q, Q-Pro, V, K-Pro, etc.

Most of these commands have been tested on Ubuntu 20.04 and should also work on most Debian-based distributions. If a command happens not to work for you, take a look in the comment section.

Make Fn + F-keys work (NOT FOR QMK-BASED BOARDS)

Older Keychron keyboards (those not based on QMK) use the hid_apple driver on Linux, even in the Windows/Android mode, both in Bluetooth and Wired modes.

Migrating from Ubuntu on WSL to ArchLinux on WSL2

Obsolete notice

This document was created back in 2020 and might not be actual nowadays. It is not supported anymore, so use thise information at your own risk.

Upgrading to WSL 2

Download WSL2 Kernel
run wsl --set-default-version 2 in windows command line, so that all future WSL machine will use WSL2.

TL;DR

Create a backup:

sudo -Hiu postgres pg_dumpall > mybackup.sql

Install Postgres 11, and then:

How to setup a practically free CDN using Backblaze B2 and Cloudflare

⚠️ Note 2023-01-21
Some things have changed since I originally wrote this in 2016. I have updated a few minor details, and the advice is still broadly the same, but there are some new Cloudflare features you can (and should) take advantage of. In particular, pay attention to Trevor Stevens' comment here from 22 January 2022, and Matt Stenson's useful caching advice. In addition, Backblaze, with whom Cloudflare are a Bandwidth Alliance partner, have published their own guide detailing how to use Cloudflare's Web Workers to cache content from B2 private buckets. That is worth reading,

Encoding high-quality HEVC content with FFmpeg - based NVENC encoder on supported hardware:

If you've built ffmpeg as instructed here on Linux and the ffmpeg binary is in your path, you can do fast HEVC encodes as shown below, using NVIDIA's NPP's libraries to vastly speed up the process.

Now, to do a simple NVENC encode in 1080p, (that will even work for Maxwell Gen 2 (GM200x) series), start with:

ffmpeg  -i <inputfile>  \
-filter:v hwupload_cuda,scale_npp=w=1920:h=1080:format=nv12:interp_algo=lanczos,hwdownload \

-c:v hevc_nvenc -profile main -preset slow -rc vbr_hq \

	#!/bin/bash
	sudo stty -F /dev/ttyACM0 1200
	echo waiting
	while [ ! -d /media/pi/RPI-RP2 ]; do sleep 0.1; done
	sleep 0.5
	if [ "$*" = "" ]; then echo rebooting; sudo picotool reboot; exit; fi
	echo copying
	cp $1 /media/pi/RPI-RP2
	echo done

	#define _GNU_SOURCE
	#include <errno.h>
	#include <sched.h>
	#include <signal.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/mount.h>
	#include <sys/stat.h>
	#include <sys/syscall.h>
	#include <sys/types.h>

	# permanent apple keyboard keyswap
	echo "options hid_apple swap_opt_cmd=1" \| sudo tee -a /etc/modprobe.d/hid_apple.conf
	update-initramfs -u -k all

	# Temporary & instant apple keyboard keyswap
	echo '1' \| sudo tee -a /sys/module/hid_apple/parameters/swap_opt_cmd

	# Windows and Mac keyboards - GUI (Physical Alt is Ctrl, Physical Super is Alt, Physical Ctrl is Super)
	setxkbmap -option;setxkbmap -option altwin:ctrl_alt_win

	# Download new packages but don't install them
	# Save in /etc/systemd/system/

	[Unit]
	Description=Pacman Automatic Download (no install) service
	After=network-online.target

	[Service]
	# Wait time if process hangs
	TimeoutStopSec=5m