Welcome

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Contents

GitHub Actions
- Components of GitHub Actions
- Workflow YAML file
  - Using Variables
  - Using Scripts and Shell Commands
  - Sharing Data Between Jobs
  - Workflow Triggers - Events
- Actions Files
  - Adding Actions
  - Action Release Management
  - Action Inputs and Outputs
  - Action File Fields
- Running Scripts
- Expressions
  - Examples
  - Literals
  - Operators
  - Functions
- Contexts
- Variables
  - Single Workflow Variables
  - Configuration Variables across multiple workflows
- Example Commenting on PR
- GitHub Actions Security
- Triggering Actions in another Repo
- Calling Reusable Workflow
- Job flow control
- Workflow inputs
- If-Else
- Setting Github Actions step output
- Writing to Github Actions Output from python
- Debugging in Github Actions
- Evaluation of inputs
- Matrix Jobs:
- Format for Json inputs
- Sources
Docker
- Useful Terms
- Commands
- Dockerfiles
- Docker Volumes
- Docker Compose
- Example Dockerfile
- Exporting an image to file
- Multi-architecture Targets
  - Building with QEMU
  - Building with Native machines
- Sources
PyTest
- Basic Test Example
- Test Subsets
- Test Classes
- Fixtures
  - Using fixtures for setup and teardown
  - Choosing fixtures at run-time
- conftest.py
- Running Tests in Parallel
- Markers
- Test Execution Results
- PyTest Hooks
- Options
- Running multiple instances of pytest on the same code
- Output Parsing
- Command line arguments
- Sources
Yocto
- Nomenclature
- Bitbake Commands
- Adding a custom C program/application
- Appending to a Recipe
- Tasks / Adding Custom Tasks
- Package Groups
  - Adding a package group
- Making your own Distro
- SystemD
  - Adding a Service
- Patch Files
  - Patching the Kernel
  - Patching Device Tree
- Editing Bitbake Files
- Creating an SDK
- Recipe Naming
- Updating Bitbake Syntax
U-Boot
- Some U-Boot Commands
- Booting using TFTP
- Booting using a FIT image
SystemD
- Service Files
- SystemD Management
- Example adding a custom service
🐍 Python
- Lambda
- Map
- Filter
- Set
- String formatting
- Checking for a type
- Equality vs Identity
- Range Length Looping
- Zip
- Timing code
- Logging
  - Logger Hierarchy
  - Text Attributes
- Exceptions
  - Handling Signals
- List comprehension
- Iterator
- Generator
- Pass Statement
- Calling C Functions from Python
- Working with Paths
- Pickle - Saving objects to files
- Environment variables
- Named Tuple
- Python Packages
  - Making a package
- Multithreading
- Decorators
  - Decorate functions
  - Decorate classes
- Context Managers
  - Exception Handling
- Virtual Environment
- Pydantic
  - Schemas
  - Validation
  - Type Management
- dis - Disassembler
- Argument Parsing with argparse
- http Server and Client
  - Client
  - Server
    - Using Gunicorn
- match
- Docker package
- Generating sheilds for Github
Linux Commands
SSH
- Authentication
  - Forwarding Credentials
- SSH Keys
- Basic Connections
- Configurations
  - Client Side Configurations
  - Server Side Configurations
- SSH Tunnels
  - Configure Local Tunnelling to a Server
  - Configure Remote Tunnelling to a Server
- SSH Escape Codes
- SSH Agent
- Sources
Multiple GitHub Accounts
- Step 1: Create Two SSH Keys
- Step 2: Configure SSH (~/.ssh/config)
- Step 3: Upload Public Keys to GitHub
- Step 4: Configure Git
- Step 5: Create Personal Folder
- Step 6: Set Up Shell Hook (~/.bashrc)
- How It Works
Bash
- Executing Scripts
- Comments
- Variables
- Input and Output
- Conditional Statements
- Looping and Branching
- Scheduling with cron
- Debugging
- Executing Shell Commands in bash
- Bash Trap
- Comparison Operators
- File Testing
- Functions
- Select
- Single and Double Quotes
- Let keyword
- Redirecting STD streans
- exec command
- Bash eval statement
- Print Colour to the console
- Environment File
- bashrc file
  - Git Branch Label
Git
- Git Hooks
- Commit Messages
🥷 Jinja
- Installation
- Basic Usage
  - Comments
- Flow Control
  - if statements
  - for loops
- Nesting templates
- Including Templates
- Whitespace
- Built-in Filters
- Macros
  - Macros in separate file
🧜‍♀️ Mermaid
- Usage
- Examples
  - Pie chart
Rust
- Installing Rust
  - Updating rust
- Basic Hello World
- Cargo
  - Release build
- Programming Concepts
- Guessing Game Example - Misc.
- Ownership
- Structures
- Enums
- Packages and Crates
- Collections
- Error Handling
- Generic Types, Traits, Lifetimes
- Automated Tests
- Command Line Program - Notes
- Iterators and Closures
  - Closures
  - Iterators
- Smart Pointers
AI tools
- Claude Code
  - Commands
  - Shortcuts
  - Instruction Files
  - MCP server
  - Hooks
  - Misc
Ansible
- Getting Started
- Playbooks
  - Using Variables
- Modules
MCP Servers
- Writing a Server
  - Testing a Server
- Clients
- Resources
  - Templated Resources
- Prompts
- Sampling
- Logs and Progress
- Roots
- Transports
MQTT
- Overview
- Packets
  - Packet Structure
- Connecting to the Broker
- Topics and Subscriptions
- Quality of Service (QoS)
- Retained Messages
- Quick Reference
- MQTT 5.0
- Security
- Broker Topology
⚔️ OpenViking
- How Embedding Models Work
  - Cosine Similarity
  - Document Summarization
- How Retrieval Works
- Self-Evolving Memory
- Use Cases
- Configuration
🤖 ROS2
- Remapping
- Topics
- Services
- Parameters
- Actions
- Logs
- Launching Nodes
- Recording and Playing Back Data
- Workspaces
- Packages
- Interfacing Between Packages
- Composable Nodes
- Testing
- RViz
- Debug
- Plugins
✏️ Prompt Engineering
- General Principles
- Examples
- Long Context Prompts
- Output Format
- Performance Tips
- Further Reading
🔌 udev Rules
- When Rules Are Checked
- File Numbering
- Anatomy of a Rule Line
- Example: ThinkPad Keyboard Backlight
📦 Python Build Tools
- Poetry
  - Common Commands
  - pyproject.toml
- uv
- Comparison
- Sources
🚗 CAN Bus
- Overview
  - Physical Layer
- Node Communication
- Frame Types
- Arbitration
- Bit Stuffing
- Frame Structure (Classical CAN)
  - CAN FD
- Synchronization
- Error Handling
- CAN Database
C++
- Visibility and Scoping
  - Inheritance Visibility
  - Structs vs Classes
- Static vs Non-static
- The << Operator
- Pointers and References
- Lvalues and Rvalues
- The this Pointer
- Move and Copy Semantics
- Unique Pointers
- Dynamic Memory Allocation
- Exceptions
- Namespaces
- Const Methods
- Templates
- Function Overloading
- Virtual Methods
- Strings and Characters
- Command Line Arguments
- Compilation Notes
- Best Practices
- Pimpl Pattern
- Shared Pointers
  - What is shared_ptr?
  - The Control Block
  - weak_ptr
  - Modifying the Data
  - Thread Safety
  - Sharing Between Threads
  - Key Mental Models
🖥️ tmux
- Core Concepts
- Sessions
- Windows
- Panes
- Configuration
- Scripting
⚡ Zephyr RTOS
- Kconfig & Build System
- Devicetree
  - Labels and Aliases
  - Node Bindings
  - Bus Disambiguation
  - Custom I2C Device
  - The chosen Node
  - Deleting Properties in Overlays
- Bare-Metal vs. RTOS
- Kernel Initialisation
- Threads
  - System Threads
  - User-Created Threads
  - Thread Lifecycle
  - Meta-IRQ Threads
  - Workqueue Threads
- Scheduler
  - Priority System
  - Cooperative Threads (priority < 0)
  - Preemptive Threads (priority ≥ 0)
  - ISRs and Thread Preemption
  - Time-Slicing
  - Earliest Deadline First (EDF)
- ISRs
- Synchronisation
  - Semaphores
  - Mutexes
  - Condition Variables
  - Events
  - Polling API
  - Busy Wait
- Data Passing
  - Queues / FIFO / LIFO
  - Stacks
  - Message Queues
  - Mailboxes
  - Pipes
- Memory Management
  - Heap
  - Memory Slabs
  - Memory Blocks Allocator
  - Demand Paging
- Timing
  - Kernel Timing
  - Timers
- Multiple Processors
- Other Kernel Services
  - Atomic Operations
  - Logging
  - Dictionary Logging
  - Fatal Errors
  - Kernel Version
- Driver Model & Device API
  - API Struct (Table of Function Pointers)
  - Dispatch Pattern
  - Three Common Patterns
  - Exposing Public Functions from a Driver
  - Writing a Custom Driver
  - Supporting Multiple Bus Types
  - Sensor Triggers
  - Power Management in Drivers
  - PM Device Actions
  - Power Domains
  - System Power Management
- Filesystems
  - Virtual Filesystem Switch (VFS)
  - Mount Points
  - Comparison to Linux
  - Embedded Constraints
  - Key Terms
  - Typical Use Cases
- User Space
  - User Space Threads
  - ARM CPU Modes and the MPU
  - Memory Domains and Partitions
  - Syscalls
  - TrustZone
  - TrustZone vs Zephyr User Space
  - Vendor / Customer Architecture
  - Enabling the gpio-leds Driver: a Kconfig Dependency Gotcha
- Debugging
  - Useful Kconfig Options
  - Breakpoints in VS Code
  - Halt Mode vs Monitor Mode
  - addr2line
  - Core Dumps
- Shell
  - Key Kconfig Symbols
  - Architecture
  - Line Redraw
  - Shell vs Logging on Same UART
  - Splitting Shell and Logging onto Different UARTs
  - Registering Shell Commands
  - Debug-Only Shell
- nRF Platform Notes
  - Pin Control and UART Power Management
  - DPPI / PPI — Peripheral-to-Peripheral Connections
- SYS_INIT
⏱️ FreeRTOS
- Task States
- Synchronisation Primitives
- Task Notifications
- Stream Buffers and Message Buffers
- Software Timers
- How an Interrupt Is Handled
  - The Ready-List Bitmap
  - Selecting the Task Within a Priority
- The Tick Interrupt
  - Tickless Idle Mode
  - SysTick and PendSV: Division of Responsibility
- Pausing the Scheduler
  - Suspend the Scheduler
  - Disable Interrupts (Critical Section)
- The Cortex-M Interrupt Priority Detail
- Memory Allocation
  - Heap Management Schemes
- Stack Size Analysis
  - Runtime Memory Checks
  - Stack Overflow Detection
- Hooks
🔨 CMake
- Command Reference
- Notes
🧠 ARM Cortex-M Memory Model
- Volatile
- Hardware Features That Affect Memory Ordering
- Barrier Instructions (CMSIS)
- Memory Types (ARM Memory Model)
- MPU and Cache Relationship
- Cache Coherency and Shared Memory
- Non-Cacheable MPU Region
Linux Driver Development
- Kernel Mechanisms
- Waiting, Sleeping and Delay Mechanisms
- Work Deferring Mechanisms
- Character Device Drivers
  - Device File Operations
  - Device Nodes
- Device Tree
- I2C Drivers
- Industrial IO Drivers
- SPI Drivers
- Resources
- Practical Reference
Cybersecurity
- Overview
- Asymmetric Cryptography
- TLS & Certificates
- Hardware Security & Device Provisioning
- Encryption Algorithms
WSL (Windows Subsystem for Linux)
- Attaching a USB Device
Debugging
- RTT — Segger Real-Time Transfer
- Compressed / Deferred Logging
  - Segger SystemView
  - Zephyr Dictionary Logging
Low Power Design
- Batteries
- Nordic Online Power Profiler
- Power Management ICs (PMICs)
- Power Analysis
  - Shunt Resistor Measurement
- Peripheral Power Domains
- Port Sense vs GPIOTE