Gabriele Baldoni gabrik

2022 Zephyrus G14 Fedora Silverblue Setup

GPU Naming

Most applications in Linux will report the names of the two GPUs as follows.

Dimgrey Cavefish is dGPU
Yellow Carp is iGPU

Boot Hotkeys

Doing import std_msgs.msg.String or from std_msgs.msg import String imports a generated Python class.

Type support

The typesupport for the String type exists on a metaclass: String.__class__._TYPE_SUPPORT. This value starts as None. It later becomes a pycapsule (with no name) when someone calls String.__class__.__import_type_support__(). This is done in rclpy by check_for_type_support(msg_type). It's called by the Node in create_...(). Afterwards inside C code the function rclpy_common_get_type_support(pymsg_type). blindly assumes _TYPE_SUPPORT is a pycapsule.

Connecting to an Android device over SSH

Initial Setup

Install Android App Termux from APKPure or AppStore. If the app exists, just delete and re-install it to get the latest version, The APK can be downloaded from https://apkpure.com/termux/com.termux/ Install the APK using by running

adb install ~/Downloads/Termux_v0.73_apkpure.com.apk

Cloud images in Proxmox

A script which automates these steps for multiple distros incl. CoreOS, CentOS, Arch and ALpine

create-cloud-template.sh

Steps for creating an Ubuntu 18.04 cloud template

Using a ready-to-use Ubuntu image

QEMU arm64 cloud server emulation

This is basically a rehash of an original post on CNXSoft - all credit (particularly for the Virtio device arguments used below) belongs to the author of that piece.

Download the latest uefi1.img image. E.g. ubuntu-16.04-server-cloudimg-arm64-uefi1.img from https://cloud-images.ubuntu.com/releases/16.04/release/

Download the UEFI firmware image QEMU_EFI.fd from https://releases.linaro.org/components/kernel/uefi-linaro/latest/release/qemu64/

Determine your current username and get your current ssh public key:

	from io import BytesIO

	from geometry_msgs.msg import Point

	p = Point(x=2, y=4)
	print(p)
	buff = BytesIO()
	p.serialize(buff)
	serialized_bytes = buff.getvalue()

	variable "bucket_name" {
	default = "max-bucket-for-testing"
	}

	provider "aws" {
	region = var.aws_region
	profile = var.aws_profile
	}

	resource "aws_s3_bucket" "artifacts" {

	// GeneratedClient here is codegen-ed

	#[tonic::async_trait]
	impl TonicClient for GeneratedClient<Channel> {
	async fn try_connect(
	dest: tonic::transport::Endpoint,
	) -> Result<Self, tonic::transport::Error> {
	GeneratedClient::connect(dest).await
	}
	}

	import cv2
	import time

	CONFIDENCE_THRESHOLD = 0.2
	NMS_THRESHOLD = 0.4
	COLORS = [(0, 255, 255), (255, 255, 0), (0, 255, 0), (255, 0, 0)]

	class_names = []
	with open("classes.txt", "r") as f:
	class_names = [cname.strip() for cname in f.readlines()]

	$ sudo nano /etc/systemd/system/startup.service

	[Unit]
	Description=Startup

	[Service]
	ExecStart=/usr/local/bin/startup.sh

	[Install]
	WantedBy=default.target