Youfu Zhang zhangyoufu

LLM Wiki

A pattern for building personal knowledge bases using LLMs.

This is an idea file, it is designed to be copy pasted to your own LLM Agent (e.g. OpenAI Codex, Claude Code, OpenCode / Pi, or etc.). Its goal is to communicate the high level idea, but your agent will build out the specifics in collaboration with you.

The core idea

Most people's experience with LLMs and documents looks like RAG: you upload a collection of files, the LLM retrieves relevant chunks at query time, and generates an answer. This works, but the LLM is rediscovering knowledge from scratch on every question. There's no accumulation. Ask a subtle question that requires synthesizing five documents, and the LLM has to find and piece together the relevant fragments every time. Nothing is built up. NotebookLM, ChatGPT file uploads, and most RAG systems work this way.

↓ on →	CPU	OpenGL	OpenGLES	D3D9	D3D11	D3D12	Vulkan	Metal
OpenGL	[llvmpipe][]	-	[gl4es][]	[TitaniumGL][]		[d3d12][]	[zink][]
OpenGLES	[llvmpipe][] [SwiftShader][slegacy]	[ANGLE][]	-	[ANGLE][]	[ANGLE][]	[d3d12][] [ANGLE][]	[zink][] [ANGLE][]	[ANGLE][] [MoltenGL][]
D3D9	[SwiftShader][slegacy]	[wined3d][]		-		[D3D9on12][]	[DXVK][]
D3D11	[WARP][]	[wined3d][]

This downloads standalone MSVC compiler, linker & other tools, also headers/libraries from Windows SDK into portable folder, without installing Visual Studio. Has bare minimum components - no UWP/Store/WindowsRT stuff, just files & tools for native desktop app development.

Run py.exe portable-msvc.py and it will download output into msvc folder. By default it will download latest available MSVC & Windows SDK from newest Visual Studio.

You can list available versions with py.exe portable-msvc.py --show-versions and then pass versions you want with --msvc-version and --sdk-version arguments.

To use cl.exe/link.exe first run setup_TARGET.bat - after that PATH/INCLUDE/LIB env variables will be updated to use all the tools as usual. You can also use clang-cl.exe with these includes & libraries.

To use clang-cl.exe without running setup.bat, pass extra /winsysroot msvc argument (msvc is folder name where output is stored).

❯ brew install blacktop/tap/ipsw

❯ ipsw download ota -V --macos --device Macmini9,1 --model J274AP

❯ unzip -l 8093b01ee46664b82427188ff61334501fd1b0d8.zip | grep DeviceTree

"What the heck is a Yubikey and why did I buy one?": A user guide

(EDIT: Besides Reddit, I've also put this up on Github Gist)

So while looking for information on security keys before getting one myself, I got very confused reading about all the different modes and advertised features of Yubikeys and other similar dongles. The official documentation tends to be surprisingly convoluted at times, weirdly organized and oddly shy about a few of the limitations of these keys (which I'm making a point of putting front and center). Now that I have one, I decided to write down everything I figured out in order to help myself (and hopefully some other people reading this) make sense of all this.

Since I'm partly writing these notes for myself, there might be some back and forth between "exp

	package main

	import (
	"debug/buildinfo"
	"encoding/json"
	"flag"
	"fmt"
	"log"
	)

	import base64
	import hashlib
	import hmac
	import locale
	import plistlib as plist
	from datetime import datetime
	import logging
	import requests
	import srp._pysrp as srp
	import urllib3

	### Unofficial Dump of UniFi system.cfg Properties
	###
	### WARNINGS:
	### - This list is undocumented, unsupported, and incomplete.
	### - Some options may be deprecated and ignored.
	### - Some options WILL break your setup.
	### - Some options work now but WILL break you in a future firmware update.
	###
	### USING THESE:
	### See https://help.ui.com/hc/articles/205146040#2

	{
	"iOS": {
	"iOS release": "01c1d682-6e8f-4908-b724-5501fe3f5e5c",
	"iOS alternate": "c724cb61-e974-42d3-a911-ffd4dce11eda",
	"iOS generic": "0c88076f-c292-4dad-95e7-304db9d29d34",
	"iOS 11 developer beta": "b7580fda-59d3-43ae-9488-a81b825e3c73",
	"iOS 11 AppleSeed beta": "f23050eb-bdfa-4b23-9eca-453e3b1a247c",
	"iOS 11 public beta": "5839f7cf-9610-483a-980f-6c4266a22f17",
	"iOS 12 developer beta": "ef473147-b8e7-4004-988e-0ae20e2532ef",
	"iOS 12 public beta": "94bf0742-38e6-4379-adf9-ec9995dde586",

	```bash
	sudo rm -rf /Users/p.xing/Library/Application\ Support/iMazing/Prefs/.sets
	```