Embedded Linux · Kernel · FPGA · 5G/6G

An Engineer's Notebook: Embedded, Kernel, 5G/6G

Personal technical notes and short research articles on embedded Linux, the Linux kernel, programming, FPGA and wireless networking (5G/6G), written in both Vietnamese and English.

Vu Tang · Firmware Team Leader, 5G/6G Project at Viettel High Tech

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341 notes10 topicssince 2019updated 2026-11-11

Quote by Paulo Coelho, the author of "The Alchemist"

Latest articles

Đổi kernel không cần reboot: kmorph, multikernel và cuộc đua live update2026-11-11Linux Kernel

Thay kernel Linux mà máy vẫn chạy, không mất dịch vụ, đang dần thành hiện thực. Năm 2025–2026 có hai hướng cùng dựa trên kexec. Hướng tuần tự (KHO/LUO) đã vào mainline…

O-RAN Release từ R001 đến R006: lịch sử, hiện trạng và lộ trình2026-11-11Wireless / RAN

Khi bắt đầu một dự án O-RAN Radio Unit (O-RU) hoặc O-RAN Distributed Unit (O-DU) mới, câu hỏi thường gặp là nên implement CUS v18 hay R005. Câu trả lời đúng là cả hai…

Bản đồ CPU Intel: từ Core Ultra đến Xeon 6+2026-11-09Chip & SoC

Cùng mang tên Xeon 6700, hai chip có thể khác nhau về kiến trúc lõi và tập lệnh. Bài viết giới thiệu ba trục để định vị mọi CPU Intel (thị trường, loại lõi, tiến trình)…

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Topics

EmbeddedBoards, boot (U-Boot, GRUB), storage, build system (Yocto, Buildroot, Petalinux), edge AI, OTA update, networking, time sync (GNSS, PTP), IoT, BMC and Linux system usage.

• Linux Embedded Overview
• Linux System
  • Overview
  • Command line và filesystem
  • User, quyền và package
  • SSH: điều khiển từ xa
  • Init system
  • Serial console
  • Tiện ích trên host
• Hardware Platforms
  • HW Platforms
  • Zynq
    • Zynq Overview
    • Zedboard
    • ZC706
    • Picozed
  • i.MX6 (DART-MX6)
  • IMX8 WIP
  • Raspberry Pi 3B
  • Rockchip (RK3399)
• MCU
  • Overview
  • Các dòng MCU phổ biến WIP
  • MCU trong hệ thống Linux WIP
• Storage
  • Chọn bộ nhớ non-volatile
  • EEPROM
• Boot
  • Bootloader Overview
  • U-Boot
  • U-Boot on Zynq
  • BIOS (Legacy)
  • EDK2 (UEFI)
  • GRUB
• Board Bring-up & Debug
  • Porting Linux lên board tùy biến
  • Log boot và earlycon
  • Debug ứng dụng user space
• FPGA SoC
  • Nạp bitstream FPGA từ Linux (Zynq)
• Build System
  • Yocto
  • Buildroot
  • Buildroot: package và BR2_EXTERNAL
  • Xilinx Petalinux
  • Root filesystem cho thiết bị
• Product Lifecycle
  • OTA Update
  • Provisioning & Device Identity WIP
• Networking
  • Overview
  • Fundamentals
  • Linux Networking Stack
  • Link Layer & Hardware
  • Tools & Debug
  • DPDK
  • Network Block Device
• Time & Sync
  • GNSS
    • GNSS Overview
    • Các hệ thống GNSS
    • GNSS trên Linux (gpsd, NMEA, 1PPS)
    • NMEA 0183
  • Linux PTP
  • Clock
    • Thạch anh và bộ dao động
    • Clock synthesizer và jitter cleaner
    • DPLL và đồng bộ mạng
• Edge AI
  • Overview
  • Edge AI trên Linux SoC có NPU
  • TinyML trên MCU
• IoT
  • IoT Overview
  • Kiến trúc Device–Gateway–Cloud
  • MCU Node & RTOS WIP
  • Connectivity
    • So sánh công nghệ kết nối
    • BLE trên Linux WIP
    • Thread, Zigbee & Matter WIP
    • LoRa / LoRaWAN WIP
    • Cellular modem WIP
    • Wi-Fi provisioning WIP
  • Protocols
    • MQTT
    • CoAP & LwM2M WIP
    • Industrial WIP
  • Edge Gateway WIP
  • Lab: Pi 3B IoT Gateway WIP
• Open Source Packages
  • Overview
  • Web Server
    • Overview & So sánh
    • lighttpd WIP
    • Nginx WIP
    • Mongoose / CivetWeb WIP
    • Backend
      • PHP WIP
• Platform Management (BMC)
  • BMC Overview
  • IPMI
  • Redfish WIP
  • OpenBMC WIP

Linux KernelDevice drivers (I2C, SPI, GPIO, UART, ALSA) and kernel debugging.

• Linux Kernel Overview
• Kernel Basics
  • Kernel Release Process
  • Kernel Boot Process
  • Kernel Command Line
  • Kernel Build (Kconfig, Kbuild) WIP
  • Kernel Module
  • Kernel Data Structure
  • Kernel Space, User Space Interfaces WIP
    • Overview
    • System Call
    • Device File & ioctl
    • Pseudo Filesystem
    • mmap, UIO, dma-buf
    • Async Notification
    • Netlink
    • Advanced Interfaces
    • ABI & Security
    • Lab
• Driver Model & Device Tree
  • Linux Device Driver Overview
  • Driver Core (kobject, sysfs, devres) WIP
  • Device Tree
  • Platform Device
  • Character Device
• Tracing & Debug
  • Overview
  • Log & Tracing
    • printk & Kernel Log
    • Dynamic Debug
    • FTrace
    • Tracepoint & Trace Events
    • eBPF & bpftrace WIP
    • perf trong kernel WIP
    • Đo độ trễ bằng tracing WIP
  • Chẩn đoán lỗi
    • Đọc Oops và Panic
    • Bộ phát hiện lỗi WIP
    • Debug bộ nhớ kernel WIP
    • Fault injection WIP
    • debugfs & truy cập thanh ghi WIP
  • Live Debug
    • KGDB & kdb
    • KGDB trên QEMU (Lab)
    • JTAG Debug (OpenOCD)
  • Post-mortem
    • Kernel Crash Dump (kdump)
• Interrupt, Memory & Concurrency
  • Interrupt & Bottom Half
  • Đồng bộ hóa (Locking)
  • Quản lý bộ nhớ trong driver
  • DMA
  • Timer & Delay WIP
• Bus Drivers
  • I2C Subsystem
  • SPI Subsystem
  • SPI Subsystem (Advanced)
  • PCIe
  • JESD204
• Hardware Frameworks
  • GPIO
  • Common Clock Framework
  • Pin Control (pinctrl)
  • Regulator
  • Power Management
  • UART
  • Audio
  • FPGA Manager
• Storage
  • Flash Storage (MTD, MMC)
• Kernel Internals
  • Process & Thread WIP
  • Scheduler WIP
  • Virtual Memory WIP
  • VFS & Page Cache WIP
  • Security Subsystem WIP
• Real-time & CPU Isolation
  • Real-time Linux (PREEMPT_RT)
  • isolcpus
  • nohz_full
  • IRQ Affinity & irqbalance

VirtualizationHypervisors (KVM, Hyper-V, Jailhouse), containers (Docker) and embedded use cases.

• Overview
• Foundations
  • CPU Virtualization
  • Memory Virtualization
  • I/O Virtualization
• Hypervisor
  • Hypervisor & Hyper-V
  • KVM & QEMU
  • Partitioning Hypervisor
• Container
  • Container Internals
  • Docker
  • Docker Compose
• Sandbox & micro-VM
• Real-time & vRAN
  • Real-time KVM tuning
  • vRAN trên VM
• Embedded Use Cases
  • Docker cho môi trường build
  • QEMU cross-arch

Wireless / RAN5G/6G RAN: CU/DU/RU and splits, Open Fronthaul, PTP synchronization, L1 acceleration and the 6G roadmap.

• Overview
• Mobile Generations
  • Generations (1G-5G)
  • 5G Usage Scenarios & Slicing
• Standards Bodies
  • ITU
  • 3GPP
  • IEEE
• O-RAN
  • Overview
  • WG1 (Architecture & Use Cases)
  • WG2 (Non-RT RIC & A1)
  • WG3 (Near-RT RIC & E2)
  • WG4 (Open Fronthaul)
  • WG6 (Cloudification & Orchestration)
  • WG11 (Security)
• Spectrum
  • Frequency Bands
  • RF Bandwidth (IBW, OBW)
  • RF Requirements (ACLR, EVM)
  • Carrier Aggregation
  • Dual Connectivity
  • DSS và Refarming
• Physical Layer (PHY)
  • OFDM
  • NR Numerology
  • Channel Coding (LDPC, Polar)
  • Physical Channels
  • Reference Signals & CSI
  • MIMO & Beamforming
• Air Interface & Procedures
  • Protocol Stack & States
  • Frame Structure & Resource Grid
  • Initial Access
  • Attach / Registration & Session
  • Connected Mode & Mobility
  • MAC Scheduler
• Architecture & Transport
  • RAN Architecture & Splits
  • RAN Deployment Models
  • Open Fronthaul
  • Synchronization
• RAN Equipment
  • RU Architecture
  • RF Transceiver & Front-end
  • DFE: CFR & DPD
  • DU/CU Architecture
  • L1 & Acceleration
• RAN Control & Automation
  • RAN Intelligent Controller
• Emerging Technologies
  • NTN Overview
  • ISAC Overview
  • AI-RAN Overview
  • 6G Roadmap

SecurityThreat model, CVE management, TLS / SSH, secure boot, TrustZone, security testing, IoT security and device compliance & certification.

• Overview
• Vulnerability Management
  • CVE
  • InsightVM (Rapid7)
• Cryptography & Transport Security
  • RSA
  • TLS
  • HTTPS
  • SSH
  • IPsec
• Secure Boot & Trusted Execution
  • Secure boot và TrustZone
• Compliance & Certification
  • Overview
  • CE Marking & RED
  • Consumer IoT
  • Telecom & RAN
• Security Testing
  • Overview
  • OWASP WSTG
  • Checkmarx và Klocwork (SAST)
• IoT
  • IoT Security WIP

ProgrammingC, build tools (Make, CMake, Git), data structures, design patterns, perf, multi-threading, shell script and Python.

• Overview
• C
  • C introduction WIP
  • C language
    • Kiểu dữ liệu và biểu thức
  • C toolchain
    • Overview
    • Build pipeline
    • Object file và ELF
    • Linking
    • Từ executable đến process
    • Build nhiều file
    • Cross compile
    • Debug và phân tích
• Build & Dev Tools
  • Makefile
  • CMake
  • Git
  • Phân tích tĩnh mã nguồn
• Coding Convention
  • Overview
  • Linux Kernel Coding Style
• Linux System Programming
  • Linux Programming Interfaces WIP
  • Multi-threading WIP
  • Ứng dụng real-time trên Linux
• Testing & Performance
  • Perf
• Design
  • Design Patterns
  • UML
• DSA
  • Overview
  • Linked List
  • Queue WIP
• Scripting
  • Shell Script
  • Python WIP
• SQL WIP
• Software Engineering
  • Development Process
  • CI/CD

Chip & SoCComputer architecture (ISA, microarchitecture, storage, SoC) and IC design (RTL, FPGA, timing analysis, verification).

• Overview
• Computer Architecture
  • Overview
  • ISA
    • Overview
    • RISC-V
    • Arm
    • x86
  • Microarchitecture
    • Overview
    • Pipeline
    • Cache
    • Memory Hierarchy
  • Storage
    • Flash (NOR, NAND, eMMC)
    • HDD & SSD
    • RAID
  • High-speed I/O
    • Line Coding (NRZ, PAM4, 8b/10b)
    • SerDes
    • PCIe
  • SoC / System
    • Overview
    • DMA Controller
    • RISC-V Server SoC Spec
• IC Design
  • Overview
  • RTL / HDL
    • Overview
    • Clock domain crossing
  • FPGA
    • Overview
    • Xilinx IPCore
  • Static Timing Analysis
  • Verification
    • Overview

Hardware DesignBoard-level hardware: passives (resistors, capacitors), power, PCB layout, SMT manufacturing and board bring-up.

• Overview
• Product Development
• Passives
• Power
• PCB Design
  • Overview
  • Differential Pair
• Form Factor
  • PCIe Add-in Card (CEM)
• Manufacturing
  • SMT
  • Quality Control (IQC, IPQC, OQC) WIP
• Bring-up & Debug

NotesBook notes, bookmarks, Mkdocs and Markdown.

• Book & Materials
  • C Programming
  • Linux Programming
  • Linux Device Driver
  • Linux Kernel
  • Linux Embedded
  • Data Structure & Algorithms
  • Others
• Math & Physics WIP
  • Overview
  • Linear Algebra
  • Probability & Statistics
  • Calculus & Fourier
  • Signals & Systems
  • Discrete Math & Boolean
  • Circuits & Electromagnetics
  • Semiconductor Physics
• Bookmarks
• Mkdocs Tool
• Markdown Language
• Đơn vị đo lường
• What's next

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