kasetty

Emulating Raspberry Pi 4 with Qemu

Just a quick update before we dive in: what we're actually doing here is running Raspberry Pi OS (64-bit) on a QEMU virtual ARM setup. This isn't full-blown hardware emulation of the Raspberry Pi 4, but more about creating a virtual environment for the OS. It doesn't mimic all the specific hardware features of the Pi 4, but it's pretty useful and great for general testing. I turned to this solution mainly to extract a modified sysroot from the Raspberry Pi OS, something not readily available in other resources. For those looking into detailed emulation of the actual Raspberry Pi 4's hardware in QEMU, check out this link for the latest updates: https://gitlab.com/qemu-project/qemu/-/issues/1208.

Hope it helps! :D

Shortcomings: No GUI yet, only console.

Steps

VM Running Raspberry Pi OS Desktop or Lite with GUI

Here's a script that creates and runs a virtual machine running Raspberry Pi OS Desktop or Lite with a GUI. It is based on cGandom's guide on setting up a Raspberry Pi OS Lite VM without a GUI. Quoting that guide:
"This isn't full-blown hardware emulation of the Raspberry Pi 4, but more about creating a virtual environment for the OS."

The main improvements made by this script over that guide are:

working GUI (tested with Raspberry Pi OS Desktop, as well as frame-buffer and X-Server on Raspberry Pi OS lite)

You probably don't know how to do Prompt Engineering

(This post could also be titled "Features missing from most LLM front-ends that should exist")

Apologies for the snarky title, but there has been a huge amount of discussion around so called "Prompt Engineering" these past few months on all kinds of platforms. Much of it is coming from individuals who are peddling around an awful lot of "Prompting" and very little "Engineering".

Most of these discussions are little more than users finding that writing more creative and complicated prompts can help them solve a task that a more simple prompt was unable to help with. I claim this is not Prompt Engineering. This is not to say that crafting good prompts is not a difficult task, but it does not involve doing any kind of sophisticated modifications to general "template" of a prompt.

Others, who I think do deserve to call themselves "Prompt Engineers" (and an awful lot more than that), have been writing about and utilizing the rich new eco-system

What do Etcd, Consul, and Zookeeper do?
- Service Registration:
  - Host, port number, and sometimes authentication credentials, protocols, versions numbers, and/or environment details.
- Service Discovery:
  - Ability for client application to query the central registry to learn of service location.
- Consistent and durable general-purpose K/V store across distributed system.
  - Some solutions support this better than others.
  - Based on Paxos or some derivative (i.e. Raft) algorithm to quickly converge to a consistent state.
Centralized locking can be based on this K/V store.

macOS 10.12 Sierra Setup

Custom recipe to get macOS 10.12 Sierra running from scratch, setup applications and developer environment. This is very similar (and currently mostly the same) as my 10.11 El Capitan setup recipe and 10.10 Yosemite setup recipe. I am currently tweaking this for 10.12 Sierra and expect to refine this gist over the next few weeks.

I use this gist to keep track of the important software and steps required to have a functioning system after a semi-annual fresh install. I generally reinstall each computer from scratch every 6 months, and I do not perform upgrades between releases.

This keeps the system performing at top speeds, clean of trojans, spyware, and ensures that I maintain good organizational practices for my content and backups. I highly recommend this.

You are encouraged to fork this and modify it to your heart's content to match your o

Two ways to do it, but only worked for me so I'll put it first and the second for reference:

$ openssl pkcs12 -export -in hostname.crt -inkey hsotname.key -out hostname.p12
$ openssl pkcs12 -in hostname.p12 -nodes -out hostname.pem

Other options for this method in comments below:

# Note, the -certfile root.crt appends all CA certs to the export, I've never needed these so it's optional for my personal steps
$ openssl pkcs12 -export -in hostname.crt -inkey hsotname.key -certfile root.crt -out hostname.p12

Note, I've always had my hostname.crt as part of my .pem, so I keep my certs but apparently you may not have to, hence the nocerts flag being an extra option in this sample

	#!/bin/bash

	if [ $# -lt 2 ]; then
	echo "usage:$0 dev output_dir [iodepth]"
	echo "example 1: Testing the whole block device. Attention: That will destory the filesystem on the target block device"
	echo "./run_fio.sh /dev/sdb fio_test"
	echo ""
	echo "example 2: Testing a file, but not destory filesystem. Suppose the target device mount on /data"
	echo "fallocate -l 1G /data/test.dat"
	echo "./run_fio.sh /data/test.dat fio_test"

	package main

	import (
	"fmt"
	"log"
	"net/http"
	"sync"
	"time"
	)