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4. BSP Development Guide

• 4.1. Setting Up the Development Environment and Compilation Instructions
  • 4.1.1. Overview
  • 4.1.2. Setting Up the Development Environment
    • 4.1.2.1. Host Machine Specifications
    • 4.1.2.2. Configuring the Host Build Environment
      • Installing Ubuntu Packages (Recommended Method)
      • Installing Python Packages (Required)
      • Manual Installation of Ubuntu Packages (Optional Method)
    • 4.1.2.3. Installing the Cross-Compilation Toolchain (GCC)
  • 4.1.3. BSP Source Code Directory Structure
    • 4.1.3.1. Top-Level Directory Structure
    • 4.1.3.2. bd.sh File
    • 4.1.3.3. device Directory
    • 4.1.3.4. build Directory
    • 4.1.3.5. out Directory
  • 4.1.4. Compilation Process and Commands
    • 4.1.4.1. Compilation Process
    • 4.1.4.2. Using the lunch Command to Select Board Configuration
      • Configuration Flow
      • Usage Methods
      • Examples
    • 4.1.4.3. Compilation Commands
      • Full Command Mode
      • Shortcut Command Mode
    • 4.1.4.4. Full Build
    • 4.1.4.5. Modular Build
    • 4.1.4.6. Non-secure Firmware
      • Overview
      • Build
      • Boot log information
    • 4.1.4.7. Clean Functions
      • clean
      • distclean
      • Help Information
  • 4.1.5. Building BSP Using Docker
    • 4.1.5.1. Install Docker
      • Step 1: Install Docker
      • Step 2: Add User to Docker Group
      • Step 3: Configure Docker Proxy Settings
      • Step 4: Verify Docker Installation
    • 4.1.5.2. Build Container Image
    • 4.1.5.3. Start Container
    • 4.1.5.4. Remove Container
    • 4.1.5.5. start_docker.sh Usage Guide
      • Usage
      • Options
      • Example
  • 4.1.6. Use Podman to compile BSP
    • 4.1.6.1. Podman Introduction
    • 4.1.6.2. Podman installation
    • 4.1.6.3. Configure Podman basic environment
      • policy.json
      • registries.conf
      • registries.conf.d/999-mirror.conf
    • 4.1.6.4. Use Podman to build container images
    • 4.1.6.5. Start the Podman container
    • 4.1.6.6. Delete Podman container
    • 4.1.6.7. start_podman.sh Instructions for use
    • 4.1.6.8. Podman FAQ
      • Reporting alias related errors when building the container
      • Missing cache file
• 4.2. Hardware Bring-Up Guide
  • 4.2.1. Hardware Bring-Up Basic Process
    • 4.2.1.1. Minimal System Preparation
    • 4.2.1.2. Hardware Board Inspection and Debugging
    • 4.2.1.3. Troubleshooting Boot Failures
    • 4.2.1.4. System Functionality Verification
    • 4.2.1.5. System Stability Testing
  • 4.2.2. Adding Board-Level Configuration
    • 4.2.2.1. Key Configuration Items Explained
    • 4.2.2.2. Partition Configuration
      • Partition Table File Description
    • 4.2.2.3. U-Boot Option Configuration
    • 4.2.2.4. Kernel Option Configuration
  • 4.2.3. Adding New Hardware in U-Boot
    • 4.2.3.1. Hardware Board ID Overview
    • 4.2.3.2. Adding a New U-Boot Configuration File
    • 4.2.3.3. Adding a New Software Board ID Definition
      • Modify Kconfig File
      • Modify Board ID Macro Definitions
      • Avoid Software Board ID Conflicts
      • Verify Added Content
      • Relationship Between Hardware Board ID and Software Board ID
    • 4.2.3.4. Adding Device Tree in U-Boot
      • Create Device Tree File
      • Include New File in Main Device Tree
      • Modify board_type Configuration
      • Notes
    • 4.2.3.5. Applying Board ID in U-Boot Configuration
      • Use the New Configuration File
      • Save Configuration
  • 4.2.4. Adding Hardware Support in Kernel
    • 4.2.4.1. Add Kernel Configuration File
    • 4.2.4.2. Add Device Tree
    • 4.2.4.3. Default Module States
    • 4.2.4.4. Edit Board-Level Device Tree
    • 4.2.4.5. Matching Software Board ID with Device Tree (DTB)
      • Configure its File to Add Device Tree
      • Notes
      • U-Boot Kernel Boot Process
  • 4.2.5. Debugging Minimal System
    • 4.2.5.1. Serial Log in Blank Chip State
    • 4.2.5.2. System Flashing
    • 4.2.5.3. Debugging Boot Stages
      • 1. miniboot boot failure
      • 2. U-Boot boot failure
      • 3. Kernel boot failure
  • 4.2.6. System Stability and Stress Testing
• 4.3. Driver Development Guide
  • 4.3.1. Address space mapping
    • 4.3.1.1. Overview
    • 4.3.1.2. Memory address space
      • SRAM and DDR address spaces
        • SRAM address space
        • DDR address space
      • SRAM and DDR address space usage
        • Linux System Memory Usage
        • Default ION Reserved Memory
  • 4.3.2. Configure U-Boot and Kernel Option Parameters
    • 4.3.2.1. Configuring U-Boot Option Parameters
      • Configuring Using the xbuild Command
      • Manual Configuration
    • 4.3.2.2. Configuring Kernel Option Parameters
      • Configuring Using the xbuild Command
      • Manual Configuration
  • 4.3.3. UART Driver Debug Guide
    • 4.3.3.1. Overview
    • 4.3.3.2. Functional Description
      • Typical Applications
      • Functional Principle
      • Operation Modes
    • 4.3.3.3. Driver Code
      • U-Boot Driver Code
      • Kernel Driver Code, Configuration, and Device Tree
        • Code Paths
        • Kernel Configuration
        • Device Tree Node Configuration
          • DTS Configuration for DMA Binding
    • 4.3.3.4. Functional Usage
      • Usage in U-Boot Stage
      • Usage in Kernel Stage
      • Usage in User Space Stage
        • Common Tool: microcom
        • Software API (Example: Loopback Test)
    • 4.3.3.5. Common Issues
  • 4.3.4. GPIO Debug Guide
    • 4.3.4.1. Overview
    • 4.3.4.2. Features
    • 4.3.4.3. Functional Description
      • Typical Application
      • Functional Principle
      • Working Mode
    • 4.3.4.4. Driver Code
      • Kernel Space
        • Kernel Configuration
        • DTS Configuration
        • Driver Code Interface
    • 4.3.4.5. Function Usage
      • U-Boot Space
        • Code Location
        • Usage Example
        • Corresponding Pins
      • User Space
        • Control Interface
        • API Usage
        • Usage Example
        • Debug Interface
        • Mapping between GPIO Number and GPIO Number in sysfs
        • Mapping between Linux GPIO Numbers and Chip Pin Numbers
        • Introduction to the hb_gpioinfo Tool
          • hb_gpioinfo Usage Example
      • Using GPIO IRQ Functionality
        • Driver Code
        • DTS Configuration
        • Driver API Interfaces
        • Driver Usage Example
        • Build Script Example
        • Usage Example
        • Experimental Results
      • FAQ
        • Makefile Compilation Path Lost
        • Makefile Compilation Version Error
        • Driver Loading Error
  • 4.3.5. Pinctrl Debug Guide
    • 4.3.5.1. Overview
    • 4.3.5.2. Features
    • 4.3.5.3. Functional Description
      • Typical Applications of Pinctrl
      • Pinctrl Functional Principle
      • Pinctrl Working Mechanism
        • Pinctrl and the GPIO Subsystem
        • Pinctrl Subsystem Architecture
      • Driver Code
        • Kernel Space
        • Kernel Configuration
        • Pinctrl DTS Configuration
    • 4.3.5.4. Using Pinctrl
      • Driver DTS Configuration
        • Pinctrl Device Tree Parsing
      • Driver Invocation Code
      • User Space Debugging
        • U-Boot Space
        • Kernel Space
  • 4.3.6. IO-Domain Debug Guide
    • 4.3.6.1. IO-Domain Overview
    • 4.3.6.2. IO-Domain Characteristics
    • 4.3.6.3. Functional Description
      • Typical IO-Domain Applications
      • IO-Domain Functional Principle
      • IO-Domain Operation Flow
    • 4.3.6.4. Driver Code
      • Kernel Space
        • Code Location
        • IO-Domain DTS
        • Driver Call Example Code
    • 4.3.6.5. Functional Usage
      • User Space
      • Uboot Space
        • Code Location
        • IO-Domain DTS
      • DTS Configuration During Driver Call
      • Command Query and Usage
    • 4.3.6.6. FAQ
  • 4.3.7. ADC Debug Guide
    • 4.3.7.1. Overview
    • 4.3.7.2. Features
    • 4.3.7.3. Functional Description
      • Typical Applications
      • Functional Principle
      • Operation Modes
    • 4.3.7.4. Driver Code
      • U-Boot
      • Kernel
    • 4.3.7.5. Functional Usage
      • U-Boot
      • User-Space Usage
        • Non-Continuous Sampling
          • Single Channel
          • Multiple Channels
        • Continuous Sampling - Scan Mode
          • DMA Mode
            • Single Channel
            • Multiple Channels
          • CPU Mode
            • Single Channel
            • Multiple Channels
    • 4.3.7.6. Common Issues
  • 4.3.8. SPI Debug Guide
    • 4.3.8.1. SPI Overview
    • 4.3.8.2. Features
      • Hardware Description
    • 4.3.8.3. Functional Description
      • Typical Application
      • Functional Principle
        • Communication Mode
        • Signal Line Description
        • Data Transfer Description
        • Communication Flow Summary
        • Clock Polarity and Phase Description
      • Operation Modes
    • 4.3.8.4. Driver Code
      • Introduction to Linux SPI Driver Framework
      • SPI Driver Code Location
      • SPI DTS Configuration Description
        • DTS Configuration for SPI Using DMA
    • 4.3.8.5. Functional Usage
      • Configuration for Using SPI1 Dual Chip Select
      • Clock Polarity and Phase Settings
      • SPI Multi-CS User Guide
        • Scenario 1: One Hardware CS + Multiple GPIO CS
        • Scenario 2: Two Hardware CS + Multiple GPIO CS
        • Scenario 3: Pure GPIO Chip Select
      • User-Space Usage
        • SPI Internal Loopback Test
        • SPI External Loopback Test
        • SPI Communication Example
        • Test Case Source Code: spidev_tc.c
        • How to Compile the Test Case Source Code:
    • 4.3.8.6. Common SPI Communication Errors and Troubleshooting Methods
      • Issues Caused by Incorrect Clock Polarity or Phase Settings
      • Common Causes of Unstable Data Transmission
      • How to Use Debugging Tools to Resolve SPI Communication Issues
  • 4.3.9. I2C Debug Guide
    • 4.3.9.1. Overview
    • 4.3.9.2. Features
      • Typical Applications
      • Functional Principle
    • 4.3.9.3. Driver Code
      • Kernel Configuration Location
      • Kernel DTS Node Configuration
    • 4.3.9.4. I2C Usage
      • I2C Usage in U-Boot Stage
      • I2C Usage in Kernel Stage
        • I2C Speed Configuration
      • I2C Slave Mode Usage
        • Overview
        • Configuration
        • Functional Test
      • User Space
        • Open-source Tool: i2c-tools
        • I2C Sysfs Frequency Control Nodes
    • 4.3.9.5. Common I2C Issues
      • Insufficient Drive Strength
      • Abnormal Device Power-Up Sequence
  • 4.3.10. LPWM Driver Debug Guide
    • 4.3.10.1. Overview
    • 4.3.10.2. Features
    • 4.3.10.3. Functional Description
      • Typical Applications
      • Functional Principle
    • 4.3.10.4. Driver Code
      • LPWM Code Path
      • Kernel Configuration
      • DTS Node Configuration
    • 4.3.10.5. Function Usage
      • Kernel Space
        • LPWM Probe Driver Source Code
        • Driver Source Code Interfaces
      • User Space
        • LPWM Configuration and Usage Instructions
        • LPWM Triggering Methods
        • LPWM Mapping Relationships
        • Sysfs Node Debugging
        • Hardware Debugging
    • 4.3.10.6. Common Issues
      • Q: If the source trigger stops after some time, will LPWM continue to output square waves?
      • Q: LPWM trigger and interrupt mechanism
  • 4.3.11. PWM Driver Debug Guide
    • 4.3.11.1. Overview
    • 4.3.11.2. Features
    • 4.3.11.3. Functional Description
      • Typical Application
      • Functional Principle
      • Operation Mode
    • 4.3.11.4. Driver Code
      • PWM Code Description
      • Kernel Configuration
      • DTS Node Configuration
    • 4.3.11.5. Function Usage
      • Kernel Space
        • Key Interfaces in Driver Code
      • User Space
        • Sysfs Node Debugging
  • 4.3.12. RTC Debug Guide
    • 4.3.12.1. RTC Overview
      • RTC Features
        • Time and Date Recording
        • Alarm and Interrupt
        • Periodic Wake-up
        • Time Update
        • Low-Power Mode
        • Hardware Interface
      • RTC Functional Principles
      • RTC Typical Applications
        • RTC Time Retention
        • RTC Periodic Wake-up
    • 4.3.12.2. RTC Driver Code
      • Linux RTC Driver Framework
      • RTC Driver Code Explanation
        • RTC Driver Layer Code Explanation
        • RTC Core Code Explanation
        • User Space Interface Code Explanation
    • 4.3.12.3. Kernel Configuration
    • 4.3.12.4. RTC Usage Overview
      • RTC Testing Methods
      • RTC Test Interfaces
        • set_rtc_time Function
        • read_rtc_time Function
        • alm_set_rtc Function
        • alm_read_rtc Function
        • alm_rtc_enable Function
        • alm_rtc_disable Function
        • RTC Test Case
    • 4.3.12.5. Common RTC Issues
  • 4.3.13. Watchdog Driver Debug Guide
    • 4.3.13.1. Watchdog Overview
    • 4.3.13.2. Watchdog Features
    • 4.3.13.3. Functional Description
      • Typical Applications of Watchdog
      • Watchdog Functional Principle
      • Watchdog Operation Modes
        • Basic Workflow of Watchdog
        • Details of Watchdog Operation
    • 4.3.13.4. Watchdog Driver Code Description
      • Watchdog Related Code Paths
      • Watchdog DTS Configuration
      • Watchdog Kernel Configuration
    • 4.3.13.5. Watchdog Function Usage
      • Watchdog Register Description
      • Watchdog Driver Key Structure Descriptions
      • Watchdog Driver Interface Functions
      • Watchdog Testing
        • Watchdog debugfs
        • Watchdog Test Example
    • 4.3.13.6. Common Issues
  • 4.3.14. Thermal System
    • 4.3.14.1. Overview of the Thermal System
    • 4.3.14.2. Functional Description of the Thermal System
      • Typical Applications of the Thermal System
      • Principle of Thermal System Functionality
      • Operation of the Thermal System
    • 4.3.14.3. Thermal Driver Code
      • Thermal-Related Code Paths
      • Thermal Device Tree Configuration
      • Thermal Kernel Configuration
    • 4.3.14.4. Functions and Usage of the Thermal System
      • Explanation of Key Structures in Thermal Driver
        • thermal_zone_device
        • thermal_governor
        • thermal_bind_params (Cooling Device)
        • thermal_instance
      • Key Function Interfaces of Thermal Subsystem
        • thermal_set_governor Function
        • thermal_register_governor Function
        • thermal_unregister_governor Function
        • update_temperature Function
        • thermal_zone_device_update Function
        • thermal_zone_device_check Function
        • thermal_zone_bind_cooling_device Function
        • thermal_zone_unbind_cooling_device Function
        • thermal_cooling_device_unregister Function
        • bind_tz Function
        • thermal_zone_device_register_with_trips Function
        • thermal_zone_device_unregister function
        • thermal_init function
    • 4.3.14.5. Thermal system debugging guide for driver platform
    • 4.3.14.6. Thermal reference documentation
  • 4.3.15. Ethernet Driver Debug Guide
    • 4.3.15.1. Overview
      • Main Functions of MAC
      • Main Functions of PHY
    • 4.3.15.2. Features
    • 4.3.15.3. Functional Description
      • Typical Application
      • Functional Principles
        • RMII
        • RGMII
        • MDIO
    • 4.3.15.4. Driver Code
      • U-Boot Driver Description
        • U-Boot Device Tree
        • U-Boot Driver Source Code
          • Typical Method to Add a New PHY Vendor Driver
      • Kernel Driver Description
        • Kernel Device Tree
        • Kernel Driver Source Code
          • Enable PHY Driver
          • Match PHY ID
          • PHY Driver Matching Check
    • 4.3.15.5. Usage
      • U-Boot Usage
        • U-Boot Set Static IP
        • U-Boot Dynamic IP Acquisition
        • U-Boot Verify PHY Connectivity
        • U-Boot Read/Write PHY Registers
      • Kernel Usage
        • Set IP Parameters
          • Set Static IP
          • Set Dynamic IP
        • Common System Commands
          • View Network Interface Status
          • Enable/Disable eth0
          • Configure eth0 Parameters
        • ethtool
          • View Network Interface Status
          • Network Interface Statistics
          • Set Network Interface Speed and Duplex Mode
        • Network Interface Speed Testing
    • 4.3.15.6. Common Issues
      • Quick Network Interface Troubleshooting
      • “Cannot attach to PHY” When Loading Network Interface
      • “MAC Reset Failed”
      • Auto-negotiation Failure
      • Unable to Ping in U-Boot / Kernel
      • Severe Packet Loss or High Number of Transmit/Receive Errors
  • 4.3.16. PMIC Driver Debugging Guide
    • 4.3.16.1. PMIC Overview
    • 4.3.16.2. PMIC Functional Description
      • Typical Applications of PMIC
        • Introduction to Typical PMIC Applications
        • Introduction to HPU3501 Typical Applications
      • PMIC Functional Principles
    • 4.3.16.3. PMIC Driver Code
      • PMIC Driver Framework
        • Introduction to the MFD Framework
        • Introduction to the Regulator Framework
        • Introduction to the Regmap Framework
        • Explanation of the PMIC Driver Framework
      • Introduction to MFD Driver Code
        • MFD Config Switch
        • MFD Code Path
        • Key MFD Code Introduction
      • Introduction to Regulator Driver Code
        • Regulator Config Switch
        • Regulator Code Path
        • Introduction to Key Regulator Code
      • Introduction to Regmap Driver Code
        • Regmap Config Options
        • Regmap Code Paths
        • Introduction to Key Regmap Code
    • 4.3.16.4. PMIC Usage Guide
      • hpu3501 MFD Layer Driver Code
        • Code Path
        • Config Switch
        • MFD Device Tree Description
        • Key Functions of hpu3501 MFD
      • hpu3501 Regulator Layer Driver Code
        • hpu3501 Regulator Code Path
        • hpu3501 Regulator CONFIG
        • Regulator Device Tree Description
        • hpu3501 Regulator Driver Code Explanation
      • hpu3501 RTC Function Overview
        • hpu3501 RTC Code Path
        • hpu3501 RTC CONFIG Switch
        • Brief Introduction to hpu3501 RTC Key Code
    • 4.3.16.5. PMIC Testing
    • 4.3.16.6. Common PMIC Issues
      • Abnormal Voltage Output
      • Communication Failure
      • Noise Interference or Power Quality Issues
    • 4.3.16.7. Reference Documents
  • 4.3.17. LCD Driver Debug Guide
    • 4.3.17.1. LCD Overview
    • 4.3.17.2. Interface Description
    • 4.3.17.3. Specifications
    • 4.3.17.4. Functional Principles
      • MIPI DSI
        • Initialization Phase (Command Mode)
        • Video Data Transmission Phase (Video Mode)
      • Touch
      • Backlight Control
    • 4.3.17.5. Debugging Procedure
      • Obtain Screen Information
      • Kernel Driver Level
      • Kernel Device Tree Level
      • Compilation
      • Testing
  • 4.3.18. USB/USB Gadget Debug Guide
    • 4.3.18.1. Overview
      • USB 2.0 OTG
      • USB 3.0 OTG
      • Related Terms
    • 4.3.18.2. Functional Description
      • Typical Applications
      • Functional Principles
    • 4.3.18.3. Code Analysis
      • USB Gadget Driver
        • Kernel Options
        • Driver Code
      • USB Gadget Scripts
      • usb-gadget.sh Script Configuration Flow
    • 4.3.18.4. USB Gadget Function Usage
      • ADB (Android Debug Bridge)
        • Code Analysis
        • Usage
      • Rndis Network Interface
        • Code Analysis
        • Usage
      • ECM Network Interface
        • Code Analysis
        • Usage
      • MSD (Mass Storage Device)
        • Code Analysis
        • Usage
      • HID (Human Interface Device)
        • Code Analysis
        • Usage
      • ACM Serial Port
        • Code Analysis
        • Usage
      • UAC (USB Audio Class)
        • Code Analysis
        • Usage
      • UVC (USB Video Class)
        • Code Analysis
        • Usage
    • 4.3.18.5. Common Issues
      • Which interfaces correspond to USB 2.0 and USB 3.0 on the X5 EVB board?
      • When using USB 2.0 to emulate a device, getting error: “usb-gadget is already running”
      • How to use USB 3.0 Gadget
      • How to switch USB 3.0 between Host and Device modes
  • 4.3.19. Audio Development and Debugging Guide
    • 4.3.19.1. Overview
    • 4.3.19.2. Features
    • 4.3.19.3. Functional Description
      • Typical Applications
      • Functional Principles
      • Operating Modes
    • 4.3.19.4. Driver Code
      • Kernel Driver Code, Configuration, and Device Tree
    • 4.3.19.5. Function Usage
      • Kernel Phase Usage
      • User-Space Usage
    • 4.3.19.6. Common Issues
      • Q1: How to troubleshoot silence issues?
      • Q2: Few LOGs, unable to locate the problem, what to do?
      • Q3: How to determine sound card registration success and PCM device correspondence?
      • Q4: What is an xrun issue, and how to locate and resolve it when encountered?
      • Q5: Errors related to opening device nodes:
  • 4.3.20. SDIO Usage Guide
    • 4.3.20.1. Overview
    • 4.3.20.2. Features
    • 4.3.20.3. Functional Description
      • Typical Applications
      • Functional Principles
    • 4.3.20.4. Driver Code
      • Kernel Driver
        • Driver Interface Description
        • Device Tree Configuration Guide
          • Notes for Peripheral Adaptation
          • eMMC
          • SD Card
          • Other SDIO Devices (e.g., Wi-Fi)
      • Kernel SDIO Framework Debugging
        • Dynamic Debug Usage Guide
        • Ftrace Usage Guide
        • MMC Controller Configuration and Runtime Parameters
      • SDIO Device Debugging
    • 4.3.20.5. Common Issues
      • 1. Unable to Recognize SDIO Device
      • 2. Card Operating Mode Does Not Match Expectation
      • 3. Controller Not Initialized
        • Notes
  • 4.3.21. Wi-Fi Driver Debug Guide
    • 4.3.21.1. Overview
    • 4.3.21.2. RealTek RTL8852BS Porting
      • Schematic Confirmation
      • Adding Source Code
        • Function Testing and Debugging
      • Kernel Configuration
        • Configuration Command
        • Configuration Options
      • DTS Configuration
        • Controller Confirmation
        • Confirm DTS Configuration
      • Build and Flash
      • Driver Loading and Debugging
      • RTL8852BS WOW Feature Verification
    • 4.3.21.3. FCS960K Porting
      • Schematic Confirmation
      • Driver Porting
        • Adding Source Code
        • Kernel Configuration
        • DTS Configuration
        • Adding Firmware
      • Build and Flash
      • Driver Debugging
    • 4.3.21.4. Wi-Fi Usage
      • Wi-Fi STA Mode Testing
        • Status Confirmation
        • Network Connection Test
      • Wi-Fi AP Mode Test
        • Switch to AP Mode
        • Status Confirmation
        • Connect to AP Hotspot
        • Test Device Connectivity
    • 4.3.21.5. Wi-Fi Performance Test
    • 4.3.21.6. Common Issues
      • Wi-Fi Interface Name Change
      • Communication Failure Error Codes
        • -110 Error Caused by CMD52
        • -110 Error Caused by CMD53
        • SDIO Enumeration Failure
  • 4.3.22. Bluetooth Driver Debug Guide
    • 4.3.22.1. Overview
    • 4.3.22.2. RealTek RTL8852BS Porting
      • Schematic Confirmation
      • Kernel Configuration
        • Configuration Command
        • Configuration Options
      • DTS Configuration
        • Confirm DTS Configuration
      • Compile and Flash
      • Driver Loading and Debugging
        • 1. Confirm Pin Multiplexing Configuration
        • 2. Load Drivers
      • Initialization Program Compilation and Firmware Configuration
        • Program Compilation
    • 4.3.22.3. FCS960K Porting
      • Schematic and Compile/Flash
      • Initialization Program
    • 4.3.22.4. Bluetooth Usage
      • Status Confirmation
      • Initialization
      • Pairing and Connection
        • 1. Enter Bluetooth Configuration Interface
        • 2. Enable Bluetooth Function
        • 3. Set Bluetooth to Discoverable Mode
        • 4. Scan Nearby Bluetooth Devices
        • 5. Pair with Other Bluetooth Devices
        • 6. Test Bluetooth Device Connection
      • Summary
    • 4.3.22.5. Common Issues
      • Bluetooth initialization fails when executing /etc/init.d/bt_init.sh
        • 1. Initialization failure due to unloaded driver
        • 2. Initialization failure due to incorrect firmware
      • Default Bluetooth Name and Modification Method
  • 4.3.23. QoS Debug Guide
    • 4.3.23.1. Overview
    • 4.3.23.2. Features
    • 4.3.23.3. Functional Description
      • Typical Applications
      • Functional Principles
        • Fixed Mode
        • Limiter Mode
        • Regulator Mode
        • Bypass Mode
    • 4.3.23.4. QoS Register Default Configuration
      • Bandwidth, BW, F Register Values
      • Mode, P1, P0 Registers
        • Notes
    • 4.3.23.5. Usage Methods
      • Common Mode
        • Reading and Writing the Priority Register
      • Advanced Mode
        • Configuring Advanced Mode
        • Configuring Priority
      • QoS Module Parameter Display Script
        • Without parameters (only read/write priorities displayed)
        • With -a parameter (all register values displayed)
      • QoS Configuration Tool qos_tool.sh
        • Module Aliases and Frequencies
        • Script Usage
        • Parameter Reference
        • Usage Examples
        • Profile File Format
        • Mode Selection Guidelines
        • Notes
  • 4.3.24. AXI-Monitor Debug Guide
    • 4.3.24.1. Overview
      • Typical Applications
      • Functional Principle
    • 4.3.24.2. Function Usage
      • Parameter Description
      • Log Description
    • 4.3.24.3. Common Issues
  • 4.3.25. X5 USB User Manual
    • 4.3.25.1. Introduction
    • 4.3.25.2. Role Switching (Host/Device)
    • 4.3.25.3. Host Mode
    • 4.3.25.4. Device Mode
      • Common Gadget Configuration Commands
    • 4.3.25.5. USB Compliance Testing
      • USB 2.0
        • Hardware Connection
        • Software Configuration
      • USB 3.0
        • Hardware Connection
        • Software Configuration
      • USB Eye Diagram Test
  • 4.3.26. boardinfo Debug Guide
    • 4.3.26.1. Overview
    • 4.3.26.2. Functional Description
    • 4.3.26.3. Driver Code
    • 4.3.26.4. Usage
      • sysfs Interface
      • Userspace API Interface
    • 4.3.26.5. Common Issues
  • 4.3.27. Time Synchronization Debugging Guide
    • 4.3.27.1. Overview
    • 4.3.27.2. Characteristics
    • 4.3.27.3. Functional Description
      • Typical Applications
      • Functional Principles
      • Working Methods
        • Hardware Layer
        • Kernel Layer
        • User-Space Layer
    • 4.3.27.4. Driver Code
    • 4.3.27.5. Function Usage
    • 4.3.27.6. Common Issues
  • 4.3.28. bootloader Usage instructions
    • 4.3.28.1. Bootloader User Guide
      • Introduction to Bootloader
        • Bootloader Configuration and Compilation
        • Key Bootloader Files
          • Configuration Files
          • Device Tree Files
          • Platform-Specific Files
      • Bootloader Boot Process
        • Analysis of Bootloader Boot Flow
        • Key Function Analysis in Bootloader Boot Flow
          • Entry Function _start
        • _main
          • board_init_f
          • board_init_r
      • Introduction to Secure Boot Process
        • BootROM Stage
        • BL2 Stage
        • U-Boot Stage
        • Linux Kernel Stage
        • Summary of Security Configuration
      • U-Boot Dynamic Configuration of Kernel ION Reserved Memory Size Usage Guide
      • U-Boot Usage Guide for dtb overlay
        • General Rules
        • Retrieve Overlay File from Fixed Location
        • Complete Configuration of Overlay File Location
      • U-Boot Configuration of Watchdog
      • U-Boot Configuration of PHY
      • U-Boot Configuration of UART
      • U-Boot Configuration of IO-Domain
      • Description of Commonly Used Commands in U-Boot
        • Environment Management Commands
          • setenv
          • printenv
          • saveenv
        • md Command
          • md Command Format
          • md Parameter Explanation
          • md Examples
          • Use Cases for md Command
          • Notes on md Command
        • mw Command
          • mw Command Format
          • mw Parameter Explanation
          • mw Examples
          • Use Cases for mw Command
          • Notes on mw Command
        • nm Command
          • nm Command Format
          • nm Parameter Explanation
          • nm Command Example
        • mm Command
          • mm Command Format
          • mm Command Parameter Explanation
          • mm Command Example
          • Differences Among Memory Modification Commands
        • I2C Command
        • gpio Command
        • dm Command
          • dm Command Format
          • dm Parameter Explanation
          • dm Command Examples
        • mii Command
          • mii Command Format
          • mii Parameter Explanation
          • mii Command Examples
        • mdio Commands
          • mdio Command Format
          • mdio Parameter Explanation
          • mdio Command Examples
      • Bootloader Glossary
    • 4.3.28.2. BL2 Configuration File Description
      • BL2 Feature Configuration
        • BL2 Watchdog Configuration
        • BL2 GPIO Configuration
          • Single Pin Configuration
          • Continuous Pin Configuration
      • DDR Configuration
        • Remapping ADC Levels and DDR Profiles
        • Enabling DDR Digital Eye Diagram
      • eFUSE Configuration
  • 4.3.29. HIFI5 Guidelines for use
    • 4.3.29.1. HIFI5 User Guide
      • Overview
        • Hardware Architecture
        • Software Architecture
      • Quick Start
        • Source Code Directory Structure
        • Compilation
        • Automatic Environment Deployment
        • Manual Environment Deployment
    • 4.3.29.2. Voice Wake-up and Sleep Example
      • Example Function Overview
      • Example Source Code Structure
      • Compilation Dependencies
      • Voice Wake-up Procedure
        • Environment Configuration
        • Test Commands
        • Algorithm Debugging Instructions
        • Runtime Result Demonstration
    • 4.3.29.3. SSF Middleware Development Guide
      • Basic Concepts
        • SGF
        • SMF
        • SIPC
      • Routing Configuration
        • Component Configuration Description
        • Link Relationship Description
        • Example
      • Algorithm Porting Guide
        • Writing a Module
        • Define MTID (Module Type ID)
        • Add Files to Makefile
        • Define CUID/MUID
        • Configure Graph
      • Communication Between A-core and DSP
      • Debugging Guide
        • Log
        • Backtrace
    • 4.3.29.4. HIFI5 Interface Documentation
      • Modules API
        • Control Interface
        • Data Interface
        • Create/Destroy Hook Interface
        • Get Module Memory Size Interface
        • Get Stack Memory Size Interface
      • ARM-side IPC Call API
      • Return Value Description
• 4.4. System Component Development
  • 4.4.1. Auto-start Configuration
    • 4.4.1.1. Overview and Introduction
    • 4.4.1.2. Detailed Functionality
      • System Boot Process
        • From Kernel to init
      • Analysis of the init Process
      • /etc/init.d/rcS
    • 4.4.1.3. Porting and Development
      • Example: Creating an Initialization Script
        • Step 1: Create the Script File
        • Step 2: Edit the Script
        • Step 3: Set Permissions
    • 4.4.1.4. Common Issues
  • 4.4.2. Integrating User Software into System Image
    • 4.4.2.1. Adding Files to the system Partition of the Root File System
    • 4.4.2.2. Creating a Dedicated Partition for Custom Files
      • Notes
      • Implementation Steps
        • 1. Modify the Partition Table
        • 2. Prepare Partition Content
        • 3. Verify and Generate Partition Image
        • 4. Integrate Build Script
        • 5. Automatically Mount the New Partition
        • 6. Package the Partition into the System Image
      • Verification
  • 4.4.3. Root Filesystem Adaptation Guide
    • 4.4.3.1. Creating Root Filesystem with Buildroot
      • Buildroot Source Code
      • Prebuilt Root Filesystems
      • Building system
      • Building initramfs
      • Building QT Support Package
    • 4.4.3.2. Use Multistrap to create Ubuntu root file system
      • Precompiled root file system
      • Make system
    • 4.4.3.3. Using APPSDK for Application Development
      • Prerequisites
        • SDK Packager (developers producing the SDK)
        • SDK User (application developers)
      • Packaging the SDK
      • Installing the SDK
        • Mode 1: sudo mode (recommended)
        • Mode 2: no-sudo mode
      • Upgrade and Uninstall
        • Upgrade
        • Uninstall
        • dpkg -r vs dpkg -P Detailed Comparison
      • Compiling Applications with the SDK
        • Method 1: Compile directly with gcc
        • Method 2: CMake projects
        • Method 3: autotools projects
        • Method 4: Build X5 projects with make (platform_samples / hbre modules)
          • Install behavior of bare make for hbre modules
      • Verifying the SDK
      • SDK Directory Structure
      • version File
      • FAQ
        • source environment-setup reports “must be sourced, not executed”
        • Using sh to source reports “requires bash, not sh”
        • Linking hbre libraries reports “cannot find -lxxx”
        • Old version residue after SDK upgrade
        • SDK does not work after moving to another path
        • environment-setup still present after dpkg -r
        • dpkg asks how to handle environment-setup during reinstall/upgrade (conffile conflict)
        • Need to re-source after upgrading the SDK
      • Notes
  • 4.4.4. System Miniaturization and Trimming
    • 4.4.4.1. Overview
    • 4.4.4.2. Introduction to System Trimming
    • 4.4.4.3. System Trimming Methods
      • U-Boot Trimming
      • Linux Kernel Trimming
        • Disable Kernel Features and Drivers
        • Modify Kernel Source Code
        • Other Trimming Directions
      • Root Filesystem Trimming
    • 4.4.4.4. Basic Principles of System Trimming
    • 4.4.4.5. System Trimming Examples
      • Minimal System Configuration
      • Minimal Kernel Configuration
      • Build and Test
        • Build New Image
        • Test the New Image
    • 4.4.4.6. Common Issues
      • Loss or Unavailability of Functionality
      • System Instability or Crashes
      • Dependency Issues
      • Performance Degradation
      • Compatibility Issues
    • 4.4.4.7. References
  • 4.4.5. Quickstart Guide
    • 4.4.5.1. Overview
      • Prerequisites
    • 4.4.5.2. Image Preparation and Flashing
    • 4.4.5.3. Boot Time Comparison Before and After Optimization
      • Measurement Tools
    • 4.4.5.4. Integrating User Software into the Quickstart Image
      • Built-in User Software
      • Adding Boot-Time Startup Scripts
    • 4.4.5.5. Quickstart Boot Chain Optimization
      • U-Boot Optimization
        • Overview
        • U-Boot Quickstart Boot Flow Diagram
        • Key Boot Chain Changes
        • Quickstart Parameter Configuration
        • Redundant Feature and Boot Path Trimming
      • Kernel Optimization
        • Overview
        • Compression Algorithm and Compiler Optimization
      • System Optimization
        • Overview
        • Main Changes
        • Lightweight init
        • Parallel boot service startup
        • Driver module load script optimization
        • Root filesystem trimming
      • Display Application Optimization
        • Overview
        • Code Location and Directory Structure
        • Display Application Startup Flow
        • Running the Application
    • 4.4.5.6. FAQ
      • How to load custom kernel modules
      • How to enable OTA (A/B partition) configuration
  • 4.4.6. ION System Debugging Guide
    • 4.4.6.1. Overview
      • ION Memory Regions
      • Characteristics of ION Memory
      • ION Region Allocation Rules
        • ION Region Adjustment Method
    • 4.4.6.2. ION Usage Methods
      • ION Region Size Adjustment Method
        • Method to Adjust ION Regions in Linux Device Tree
        • Method to Adjust ION Regions in U-Boot
      • ION Debugging Methods
        • View Statistics of Each ION Region
        • View Statistics of Clients Allocated ION Memory
      • ION Region Name Mapping Table
    • 4.4.6.3. Adjusting ION Region Size Based on Application Scenarios
      • Theoretical Calculation of ION Resource Usage
        • Camera-related Modules
          • HBN Framework
          • Background Service Programs
        • VPU
          • H.264 Encoding
          • H.265 Encoding
        • BPU
      • Validating Theoretical Values
        • Camera Modules
        • BPU Module
        • Other Modules
      • Modify and Apply ION Region Configuration
  • 4.4.7. Log System Introduction
    • 4.4.7.1. Introduction to Linux Log System
      • Log Buffer
      • Log Writing Interfaces
        • printk Function
        • Common Logging Interfaces in Drivers
        • Interfaces for Use Without a Device Structure
        • Application-Level Log Interfaces
      • Log Extraction
        • Console
        • /dev/kmsg
        • syslogd
    • 4.4.7.2. Log Directory Structure
      • Log Partition
      • Log Partition Content Description
    • 4.4.7.3. Log Management
      • Log Processes
        • Log Process Information Explanation
        • Log Process Startup Order Explanation
      • Log Management Methods
        • hobot-log Script Overview
        • Customizing the Log System for Users
      • pstore
        • Pstore Mechanism
        • Configuring pstore
        • pstore Log Archiving
        • pstore usage example
    • 4.4.7.4. log debug
      • log debugging notes
      • How to preserve effective logs during system hang
      • How to effectively obtain logs from the time of issue
    • 4.4.7.5. Recording AB/BAK abnormal switch reasons
      • Introduction
      • hrut_switch_reason tool usage
        • On-device tool
        • PC tool
        • Usage examples
        • Test case construction
          • mmc
          • flash
      • View via cmdline
      • View via system log
  • 4.4.8. Information Security Development Guide
    • 4.4.8.1. Introduction to security hardware
      • Overview
        • Introduction
        • Security Algorithms
      • Hardware Security Driver
        • Driver Source Code
        • Enabling Hardware Security
          • Kernel Configuration
          • DTS Configuration
          • Loading the Driver
      • Notes
    • 4.4.8.2. FDE Full disk encryption
      • Overview
        • Introduction
        • FDE Principle
        • Terminology
      • FDE Tools
        • cryptsetup
          • Working Principle
        • dm-crypt
          • Working Principle
      • X5 FDE User Password Management
      • X5 FDE Usage
        • System Partition Encryption
          • Solution Principle
          • Usage Method
            • Change the system partition verification method to crypt
            • Create system FDE image
            • User root key
            • Build and Boot
        • User Partition Encryption: key-hobot Solution
          • Add New Partition
          • Add FDE Configuration in hb-crypttab
          • Create Mount Point Directory in Root Filesystem
          • Build and Boot
        • User Partition Encryption: key-file Solution
          • Solution Principle
          • Usage Method
            • 1. Add Partition and Build Script
            • 2. Encryption/Decryption Key File
            • 3. Add Encryption Partition Build Script
            • 4. Source Files for User Encrypted Partition
            • 5. Build
          • Boot Verification
    • 4.4.8.3. FBE File encryption
      • FBE File Encryption
        • Overview
        • X5-FBE Usage
          • Using External Key
          • Using X5 Derived Key
    • 4.4.8.4. Safe start
      • X5 Secure Boot Overview
      • Uboot & BL2 CFG Verification
        • Process Overview
          • PC-side Signing Process
          • Board-side Verification Process
        • Key Management
          • Generation and Programming of Uboot and BL2 CFG Keys
      • Kernel & Rootfs Verification
        • Overview of AVB and dm-verity
        • AVB and dm-verity Verification Process
        • Key Management
          • Generation and Programming of User Keys
      • Software Version Anti-Rollback
        • Introduction
        • Enabling Anti-Rollback Function
        • Setting and Updating Anti-Rollback Version
        • Limitations
      • Enabling Secure Boot
        • Configuring eFuse
        • Checking if Secure Boot is Enabled
        • Configuring System Image
        • Enabling dm-verity on OEM Partition
          • Add OEM Partition in Partition Table
          • Add Mount Point
          • Configure Auto-mount
          • Packaging OEM Image
          • Notes on oem Partition Upgrade
      • Verifying Secure Boot
    • 4.4.8.5. boot encrypt
      • boot encryption introduction
      • boot encryption usage
        • boot encryption principle
        • Enabling boot encryption
      • boot key storage
        • boot encryption key storage
        • U-Boot retrieving the key
          • Method 1: Retrieve via DTS
            • Usage
          • Method 2: Retrieve via RPMB
            • RPMB Introduction
            • Usage
    • 4.4.8.6. TEE
      • ARM TrustZone
        • System Architecture
        • CPU Privilege Levels
        • Glossary
      • About X5 TEE
        • Implementation Mechanism
        • Firmware Acquisition
        • Version Information
          • BL31
          • OP-TEE
      • TA Development
        • Overview
        • Building TA
        • TA Signing and Encryption
          • TA Signing
            • Generate a New Private Key File
            • Replace Public Key in OP-TEE OS
            • Compile TA
          • TA Encryption
            • Enable TA Encryption
            • Modify Key File
            • Compile TA
            • Notes
        • Building TA Separately
        • Deploying TA
    • 4.4.8.7. eFuse Burning
      • X5 eFuse Introduction
        • Overview
        • X5 eFuse Features
      • BL2 eFuse Programming
        • eFuse Configuration File
        • eFuse Power Control and Programming Status
          • eFuse Programming Status
          • eFuse Power Control
          • Usage Example
      • U-Boot Read/Write eFuse
        • Read eFuse
          • Read Specific eFuse Bank Value
        • Write eFuse
        • Notes
      • Linux Read/Write eFuse
        • API Reference
        • Data Structures
          • efuse_type
          • efuse_info
        • Interface Descriptions
          • drobot_efuse_read
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
          • drobot_efuse_write
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
      • Notes
        • Procedure for Enabling Secure Boot
        • Forcibly Enabling Debug Port
      • X5 Customer Root RSA Key Hash Burning and Usage
        • Introduction
        • Replacement of Customer Root RSA Private Key
        • Burning Customer Root Public Key Hash
          • BL2_CFG Burning
          • hbre libefuse Burning
            • Example of Official Interface Usage
            • Debug Interface Example
          • Dump eFuse Burn Status
        • Image Compilation
        • Notes
    • 4.4.8.8. secure storage
      • X5 Secure Storage Introduction
      • KEY Management
        • File Encryption/Decryption Key Management
          • SSK (Secure Storage Key)
          • TSK (Trusted Application Storage Key)
          • FEK (File Encryption Key)
        • RPMB KEY Management
      • Secure Storage Operation Interfaces
        • Basic Information
        • Return Value Description
        • API Reference
        • Interface Descriptions
          • drobot_st_file_load
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
          • drobot_st_file_store
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
          • drobot_force_rpmb_key_ready
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
          • drobot_is_st_file_exist
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
          • drobot_st_file_delete
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
          • drobot_st_file_rename
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
          • drobot_get_device_unlock
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
          • drobot_set_device_unlock
            • 【Function Declaration】
            • 【Function Description】
            • 【Parameter Description】
            • 【Return Value】
            • 【Notes】
            • 【Compatibility】
            • 【Example Code】
      • Secure Storage Operation Commands
        • Basic Information
        • Usage
  • 4.4.9. OTA
    • 4.4.9.1. OTA Functionality and Introduction
      • Overview and Introduction
      • System Partition Table
      • Detailed Functional Description
        • Seamless OTA Update
          • AB Partition Seamless Update
          • BAK Upgrade
          • GOLDEN Upgrade
        • Partition Flashing Methods
          • Full-Image Upgrade
          • Differential Image Upgrade (eMMC only)
        • OTA Security Measures
          • Image Rollback Protection
            • Enable antirollback
            • Version Number Retrieval
          • OTA Version Verification
          • Partition Verification
        • OTA Upgrade Process
      • Introduction to the OTA Packaging Module
        • Packaging Images
          • Usage of Packaging Tool
          • Full Image Packaging Method
          • Differential Image Packaging Method
        • Signing Keys
        • OTA Upgrade Package Introduction
          • Package Structure
          • OTA Configuration File
      • OTA Upgrade End Introduction
        • ota_tool Usage
        • ota_tool Implementation
          • ota_update_all_img Implementation
          • ota_boot_check Implementation
    • 4.4.9.2. OTA API
      • Error Types Returned by Dynamic Library Interfaces
      • Interface List
        • otaInitLib
          • 【Example Code】
        • otaDeinitLib
          • 【Example Code】
        • otaGetLibVersion
          • 【Example Code】
        • otaRequestStart
          • 【Example Code】
        • otaGetResult
          • 【Example Code】
        • otaGetProgress
          • 【Example Code】
        • otaGetUpdatingImageName
          • 【Example Code】
        • otaGetSysVersion
          • 【Example Code】
        • otaGetPartition
          • 【Example Code】
        • otaSetPartition
          • 【Example Code】
        • otaGetOwnerFlag
          • 【Example Code】
        • otaMarkOTASuccessful
          • 【Example Code】
        • otaCheckUpdate
          • 【Example Code】
        • otaClearFlags
          • 【Example Code】
        • otaPartitionSync
          • 【Example Code】
  • 4.4.10. USB Flash Drive Update Function
    • 4.4.10.1. Overview and Introduction
      • Introduction
      • Prerequisites
    • 4.4.10.2. Feature Description
      • Update Types
      • Update Directory Layout
      • Update Procedure
        • Step 1: Prepare the update image file
        • Step 2: Insert the USB flash drive
        • Step 3: Power on the device
      • Serial Log Reference
    • 4.4.10.3. Upgrade Steps
      • Pre-upgrade Checks
      • Full-image update
      • Split full-image update
      • Partition Upgrade
      • Manual usbupdate
    • 4.4.10.4. Porting Guide
      • Code Paths
      • Code Integration
      • Update Flowchart:
    • 4.4.10.5. Common Issues
      • How to determine if the device supports automatic USB flash drive update?
      • USB drive inserted but no update occurs
      • Checking the update result
      • Update failure
      • emmc_disk.img exceeds 4 GB per file
  • 4.4.11. Low Power Mode Debugging Guide
    • 4.4.11.1. Overview and Introduction
    • 4.4.11.2. Detailed Explanation of Low Power Debugging
    • 4.4.11.3. Dynamic Voltage and Frequency Scaling (DVFS)
      • Frequency and Voltage Adjustment Methods
        • CPU Frequency and Voltage Scaling
        • BPU Frequency Scaling
        • GPU 3D Frequency Scaling
        • DDR Frequency Scaling
        • Dynamic Adjustment Explanation
          • Load-Based Dynamic Adjustment
          • Temperature-Based Dynamic Adjustment
          • Other Dynamic Adjustment Strategies
      • Porting and Development
        • Kernel Configuration
        • Linux Power Management Core Framework
        • DVFS Testing
      • Common DVFS Issues
    • 4.4.11.4. Suspend and Resume
      • Suspend and Resume Methods
        • Suspend Command
        • Resume Commands
      • Porting and Development
        • Kernel Configuration
        • Overview of Linux System Suspend / Resume Process
      • System Suspend and Wake-up Testing
      • Common Suspend/Resume Issues
    • 4.4.11.5. Typical Scenario Power Consumption
  • 4.4.12. System Performance Optimization Guide
    • 4.4.12.1. Overview
      • Analysis of Causes of Performance Issues
        • Causes of CPU Performance Issues
        • Causes of Memory Performance Issues
        • Causes of Disk Performance Issues
        • Causes of Network Performance Issues
        • Causes of System Configuration Issues
      • Performance Optimization Goals
      • Performance Optimization Layers
      • Fundamental Principles of Performance Optimization
    • 4.4.12.2. Performance Diagnostic Tools
      • top
        • How top Works
        • Description of /proc/stat and /proc/loadavg Files
        • Difference Between CPU Utilization and Load Average
        • Limitations of top
        • top Command Options
        • Usage of top
        • Introduction to htop
      • mpstat
        • Principle of mpstat
        • mpstat Parameter Description
        • Usage of mpstat
        • mpstat Example
      • pidstat
        • Principle of pidstat
        • pidstat Parameter Description
        • Usage of pidstat
        • pidstat Examples
      • iostat
        • iostat Parameter Description
        • Usage of iostat
        • iostat Example
        • Explanation and Common Misunderstandings of iowait
      • vmstat
        • Principle of vmstat
        • vmstat Parameter Explanation
        • vmstat Usage Instructions
        • vmstat Example
      • free
        • Principle of free
        • free Parameter Explanation
        • free Usage Instructions
        • free Example
      • uptime
        • Principle of uptime
        • uptime Parameter Description
        • uptime Usage Instructions
        • uptime Examples
      • sar
        • sar Principle
        • sar Parameter Description
        • sar Usage Instructions
        • sar Examples
        • Common sar Commands
      • iozone
      • iperf3
      • netstat
        • How netstat works
        • netstat Parameter Descriptions
        • netstat Usage Guide
        • netstat Examples
        • Brief Introduction to ss
      • Summary of Performance Diagnosis Tools
      • Introduction to Other Performance Analysis Tools
    • 4.4.12.3. System Optimization Strategies
      • CPU Optimization
        • Adjusting Process Priority
        • Reducing Context Switching
        • CPU Affinity
        • Real-time Optimization
      • Memory Optimization
        • Swap Management
        • Transparent Huge Pages (THP)
        • OOM Killer Configuration
      • Storage Optimization
        • File System Selection
        • I/O Scheduler Selection
        • Reducing Write Operations
        • Flash Wear Leveling
        • Enabling TRIM Support
      • Network Optimization
        • TCP Parameter Tuning
        • Multi-queue NIC
        • Connection Limit
    • 4.4.12.4. Application Optimization
      • Coding Principles
      • Daemon Thread Optimization
      • Dynamic Library Loading Optimization
        • Reduce Loading of Unused Dynamic Libraries
        • Reorganize Dynamic Library Structure
        • Compile Dynamic Libraries into Static Libraries
        • Use dlopen for Dynamic Library Loading
    • 4.4.12.5. Introduction to the USE Method
      • Core Concepts of the USE Method
      • Workflow of the USE Method
      • Performance Analysis Steps Based on the USE Method
      • USE Method Metrics List
    • 4.4.12.6. Case Study
      • Writing Test Cases
      • Test Analysis
        • High-Load Task Simulation
        • Simulating frequent context switches
        • Simulating excessive interrupt handling
    • 4.4.12.7. References
• 4.5. Driver function unit test
  • 4.5.1. Overview
    • 4.5.1.1. Test Program Storage Path
    • 4.5.1.2. Test Environment Preparation
    • 4.5.1.3. Test Execution Method
    • 4.5.1.4. Test Objectives and Standards
  • 4.5.2. AutoTest Usage Guide
    • 4.5.2.1. AutoTest Directory Structure
    • 4.5.2.2. config.ini Configuration File Description
      • Configuration File Structure
      • Configuration File Example
      • Usage Instructions
    • 4.5.2.3. Starting Tests with startup.sh
    • 4.5.2.4. Viewing Test Logs
      • Modifying Log Storage Path
    • 4.5.2.5. Adding New Test Items
      • Write the Test Script
      • Configure the config.ini File
      • Start the Test
      • Verify the Test Item
  • 4.5.3. CPU-BPU-DDR Stress Test
    • 4.5.3.1. Test Principle
    • 4.5.3.2. Preparations
    • 4.5.3.3. Test Method
    • 4.5.3.4. Test Metrics
      • Test Results
  • 4.5.4. eMMC Stress Test
    • 4.5.4.1. Test Principle
      • Test Content
        • eMMC Stability Stress Test
        • eMMC Performance Test
    • 4.5.4.2. Preparation
    • 4.5.4.3. Test Method
      • eMMC Stability Test:
      • eMMC Performance Test:
    • 4.5.4.4. Test Metrics
      • eMMC Stability Test
      • eMMC Stability Test Results
      • eMMC Performance Test
      • eMMC Performance Test Results
  • 4.5.5. QSPI NAND Flash Stress Test
    • 4.5.5.1. Test Principle
      • Test Content
    • 4.5.5.2. Preparation
    • 4.5.5.3. Test Method
    • 4.5.5.4. Test Metrics
      • QSPI NAND Flash Test Results
  • 4.5.6. UART Stress Test
    • 4.5.6.1. Test Principle
      • Test Content
    • 4.5.6.2. Preparation
      • Instructions for Using the Stress Test Script
      • Instructions for Running the Test Program
      • Notes
    • 4.5.6.3. Test Metrics
      • UART Stress Test Results
  • 4.5.7. SPI Stress Test
    • 4.5.7.1. Test Principle
      • Test Content
    • 4.5.7.2. Preparation
      • Stress Test Script User Manual
      • spistress.sh
      • spidev_tc
      • Precautions
    • 4.5.7.3. Test Method
    • 4.5.7.4. Test Metrics
      • SPI Stress Test Results
  • 4.5.8. Wi-Fi Performance Testing
    • 4.5.8.1. Test Preparation
    • 4.5.8.2. Test Method
      • Step 1: Start the Server
      • Step 2: Start the Client
    • 4.5.8.3. Test Results
    • 4.5.8.4. Performance Standards
  • 4.5.9. Ethernet Performance Testing
    • 4.5.9.1. Throughput Testing
      • Test Principle
      • Preparations
      • Example Configuration
      • Test Method
        • Step 1: Start the Server
        • Step 2: Start the Client
      • Test Criteria
        • Test Results
    • 4.5.9.2. MTU Performance Testing
      • Test Principle
      • Preparations
      • Test Method
        • Step 1: Start the Server
        • Step 2: Start the Client
      • Test Criteria
        • Configuration Check
        • Target MTU Comparison
    • 4.5.9.3. Common Issues
      • 1. Why can’t the iperf3 client connect to the server?
      • 2. Why is the measured bandwidth lower than expected?
      • 3. Why is there high packet loss during testing?
      • 4. How to resolve the “Address already in use” error when running iperf3?
      • 5. Why do MBytes and Bitrate look the same across MTU test tiers?
      • 6. Why is MTU 9000 not tested?
  • 4.5.10. CPU Performance Test
    • 4.5.10.1. Test Principles
    • 4.5.10.2. Test Preparation
    • 4.5.10.3. Test Method
    • 4.5.10.4. Test Metrics
      • Scoring Standards
      • Understanding the Scoring Standards
    • 4.5.10.5. Common Issues
  • 4.5.11. DDR Bandwidth Test
    • 4.5.11.1. Test Principle
    • 4.5.11.2. Preparation
    • 4.5.11.3. Test Method
    • 4.5.11.4. Test Metrics
      • Scoring Criteria
      • Test Result
  • 4.5.12. USB Bus Speed Test
    • 4.5.12.1. Test Principle
      • Test Content
        • Explanation of dd Command Principle
        • Explanation of USB Virtual Network Interface Principle
    • 4.5.12.2. Preparation
      • USB Drive Read/Write Preparation Method
    • 4.5.12.3. Test Method
    • 4.5.12.4. Preparation
      • USB Virtual Network Interface Preparation Method
    • 4.5.12.5. Test Method
    • 4.5.12.6. Test Metrics
      • Common Influencing Factors
      • Test Results
  • 4.5.13. 2D GPU Performance Test
    • 4.5.13.1. Test Principle
    • 4.5.13.2. Test Preparation
    • 4.5.13.3. Test Method
    • 4.5.13.4. Test Metrics
    • 4.5.13.5. Common Issues
  • 4.5.14. 3D GPU Performance Test
    • 4.5.14.1. Test Principles
    • 4.5.14.2. Test Preparation
    • 4.5.14.3. Test Methods
      • Rendering Performance Test Method
      • Computing Performance Test Method
    • 4.5.14.4. Test Metrics
      • Rendering Performance Metrics
        • General Rendering Tests
        • Complex Computation Tests
        • Computational Tests
      • Computing Performance Metrics
        • Memory Bandwidth (GBPS)
        • Single-Precision Compute Performance (GFLOPS)
        • Half-Precision Compute Performance (GFLOPS)
        • Integer Compute Performance (GIOPS)
        • Transfer Bandwidth (GBPS)
        • Kernel Launch Latency
    • 4.5.14.5. Common Issues
  • 4.5.15. GPIO IRQ Test
    • 4.5.15.1. Test Principle
    • 4.5.15.2. Test Preparation
    • 4.5.15.3. Test Method
      • Load the Driver
      • Test with the Driver
    • 4.5.15.4. Test Metrics
    • 4.5.15.5. Test Results
  • 4.5.16. Bluetooth Performance Testing
    • 4.5.16.1. Test Preparation
    • 4.5.16.2. Test Method
      • Step 1: Start the Server
      • Step 2: Start the Client
    • 4.5.16.3. Test Results
    • 4.5.16.4. Performance Standards
    • 4.5.16.5. Common Issues
      • 1. Connection disconnects after executing bt-network
  • 4.5.17. ADC Test
    • 4.5.17.1. Test Principle
    • 4.5.17.2. Preparation
      • Script Usage
      • Parameter Description
      • Notes
    • 4.5.17.3. Test Steps
      • Single Sampling Test
      • Continuous Sampling Test
    • 4.5.17.4. Test Criteria
      • Output Information
      • Result Assessment
  • 4.5.18. Watchdog Test
    • 4.5.18.1. Test Principle
    • 4.5.18.2. Preparation
      • Script Usage
    • 4.5.18.3. Test Steps
      • Check Default Timeout
      • Check Feeding Source
      • Check Remaining Timeout
      • Feed Test
      • Disable Watchdog
    • 4.5.18.4. Test Metrics
  • 4.5.19. RTC Test
    • 4.5.19.1. Test Principle
    • 4.5.19.2. Preparation
      • Driver Verification
      • Script Path
      • Script Usage
    • 4.5.19.3. Test Steps
      • View RTC Information
      • Read RTC Time
      • Set System Time
      • Set RTC Time
      • RTC Alarm Test
    • 4.5.19.4. Test Criteria
• 4.6. System debugging method
  • 4.6.1. pstore & ramoops
    • 4.6.1.1. Introduction to pstore
    • 4.6.1.2. pstore Principle
    • 4.6.1.3. pstore Types
    • 4.6.1.4. Introduction to ramoops
    • 4.6.1.5. ramoops Usage
      • Enable ramoops in Kernel
      • Configure ramoops Reserved Memory
      • Trigger Kernel Panic in Kernel
      • Verify ramoops Functionality
  • 4.6.2. mem-dump Feature Guide
    • 4.6.2.1. Overview
      • Introduction
      • mem-dump Information
        • User Space Information
        • Kernel Information
        • Crash Context
    • 4.6.2.2. X5 mem-dump Feature Introduction
      • Feature Highlights
      • Functional Principle
    • 4.6.2.3. mem-dump Configuration
      • Get panic-action
      • Configure panic-action
    • 4.6.2.4. mem-dump Usage
      • Configure panic-action
      • Perform mem-dump to emmc
    • 4.6.2.5. mem-dump Analysis Method
    • 4.6.2.6. Common Issues
      • panic-action not configured before crash
      • Does configuring panic-action affect reboot or cold boot?
  • 4.6.3. Using GDB to Debug Applications
    • 4.6.3.1. GDB Overview
    • 4.6.3.2. Main Features of GDB
    • 4.6.3.3. Common GDB Debugging Commands
    • 4.6.3.4. Introduction to Specific GDB Debugging Methods
      • Writing a Test Program
      • Compilation
      • GDB Debugging Process
      • Analyzing Core Dump Files with GDB
    • 4.6.3.5. Common Issues
    • 4.6.3.6. References
  • 4.6.4. Using Kdb/Kgdb to Debug the Kernel
    • 4.6.4.1. Overview of Kdb/Kgdb
    • 4.6.4.2. Introduction to Kdb/Kgdb Features
      • Introduction to Kdb Features
      • Introduction to Kgdb Features
      • Comparison Between Kdb and Kgdb
    • 4.6.4.3. Specific Usage Methods of Kdb/Kgdb
      • Enabling Kdb/Kgdb
      • Starting Kdb Debugging on the Board
        • Starting Kdb During U-Boot Stage
        • Starting Kdb After Kernel Boot
      • Introduction to Kdb Debugging Commands
      • Remote Connection to Board for Kgdb Debugging
    • 4.6.4.4. Common Issues
      • Common Kdb Issues
      • Common Kgdb Issues
  • 4.6.5. DDR Digital eye diagram
    • 4.6.5.1. X5 DDR digital eye diagram tool instructions and results analysis
      • background
      • Tool usage instructions
        • reboot command
        • bl2_cfg configuration
      • DDR eye diagram analysis
        • Eye diagram information description
      • Eye diagram evaluation criteria
      • Notes
• 4.7. Common command usage methods
  • 4.7.1. Iozone
    • 4.7.1.1. Syntax Description
    • 4.7.1.2. Parameter Options Introduction
    • 4.7.1.3. Usage Examples
  • 4.7.2. iperf3
    • 4.7.2.1. Syntax Description
    • 4.7.2.2. Introduction to Common Options
    • 4.7.2.3. Test Result Analysis
    • 4.7.2.4. Usage Examples
  • 4.7.3. perf
    • 4.7.3.1. Syntax Description
    • 4.7.3.2. Parameter Options Description
    • 4.7.3.3. Command Options and Functional Descriptions
      • perf System Analysis
      • perf Event Types
      • perf Process Statistics
        • Common perf stat Options
      • perf record - Collect Information
      • perf report - Analyze Results
      • Generate Flame Graph with perf
        • Step 1
        • Step 2
        • Step 3
        • Step 4
        • Flame Graph Interpretation
  • 4.7.4. sysinfopro
    • 4.7.4.1. Syntax Description
    • 4.7.4.2. Option Parameters Description
    • 4.7.4.3. Command Options and Their Functional Descriptions
      • Display All Information
      • Display Memory Information
      • Display Hardware Information
      • Display Operating System Version Information
      • Display Temperature and Frequency Information
      • Display Board Terminal Basic Information
      • Display HBRE Library Version Information
      • Display Currently Loaded Kernel Modules
      • Display Help Information
  • 4.7.5. devmem
    • 4.7.5.1. Syntax Description
    • 4.7.5.2. Parameter Options Description
    • 4.7.5.3. Command Options and Their Functional Descriptions
      • Reading Data from Physical Address
      • Writing Data to Physical Address
  • 4.7.6. hb_gpioinfo
    • 4.7.6.1. Syntax Description
    • 4.7.6.2. Parameter Options Description
    • 4.7.6.3. Command Options and Their Function Descriptions
      • Display Help Information
      • Display All GPIO Pin Information
      • Display Information for a Specific GPIO Chip
  • 4.7.7. hrut_boardid
    • 4.7.7.1. Syntax Description
    • 4.7.7.2. Option Arguments Description
    • 4.7.7.3. Command Options and Function Descriptions
      • Default Usage
      • Display Help Information
  • 4.7.8. hrut_bpuprofile
    • 4.7.8.1. Syntax Description
    • 4.7.8.2. Option Arguments Description
    • 4.7.8.3. Command Options and Their Functional Descriptions
      • Setting BPU Power
      • Setting BPU Clock
      • Getting BPU FC Time
      • Setting BPU Frequency
      • Setting BPU Utilization Display
      • Displaying Help Information
  • 4.7.9. hrut_ddr
    • 4.7.9.1. Syntax Description
    • 4.7.9.2. Option Descriptions
    • 4.7.9.3. Command Options and Their Functionalities
      • Display Help Information
      • Monitor DDR Bandwidth Across All Ports
      • Monitor DDR Bandwidth on a Specific Port
      • Display Detailed Information in Raw Data Format
      • Set Sampling Period
  • 4.7.10. hrut_ddr_freq
    • 4.7.10.1. Syntax Description
    • 4.7.10.2. Command Options and Their Functions
      • Default Usage
  • 4.7.11. hrut_resetreason
    • 4.7.11.1. Syntax Description
    • 4.7.11.2. Command Options and Function Descriptions
      • Default Usage
  • 4.7.12. hrut_sched_log_parse
    • 4.7.12.1. Syntax Description
    • 4.7.12.2. Parameter Options Description
    • 4.7.12.3. Command Options and Their Functional Descriptions
      • Usage Description
      • Parsing Scheduling Log Files
      • Parsing Console Log Files
      • Parsing Kernel Log Files
      • Display Help Information
  • 4.7.13. hrut_socuid
    • 4.7.13.1. Syntax Description
    • 4.7.13.2. Command Options and Their Functional Descriptions
      • Default Usage
  • 4.7.14. hrut_somstatus
    • 4.7.14.1. Syntax Description
    • 4.7.14.2. Option Arguments Description
    • 4.7.14.3. Command Options and Functional Descriptions
      • Default Usage
      • Display Multiple Status Readings
      • Set Interval Time Between Outputs
  • 4.7.15. hrut_switch_reason
    • 4.7.15.1. Syntax Description
    • 4.7.15.2. Parameter Options Description
    • 4.7.15.3. Command Options and Their Function Descriptions
      • Display the Reason for the Most Recent Abnormal Switch
      • Display Reasons for All Abnormal Switches
      • List of Abnormal Switch Reasons
  • 4.7.16. logcat
    • 4.7.16.1. Syntax Description
    • 4.7.16.2. Parameter Options Description
    • 4.7.16.3. Command Options and Their Function Descriptions
      • Default Usage
      • Display Logs of Specific Priority
      • Output Logs to File
      • Rotate Log Files
      • Clear Log Buffer
      • Get Log Buffer Size
      • Display Logs from Specific Buffer
  • 4.7.17. ota_tool
    • 4.7.17.1. Syntax Description
    • 4.7.17.2. Parameter Options Description
    • 4.7.17.3. Command Options and Their Functional Descriptions
      • Query Version Information
      • OTA Partition Management
      • OTA Firmware Update
      • OTA Status Check
• 4.8. Approved Vendor List
  • 4.8.1. Introduction
  • 4.8.2. DDR Support List
    • 4.8.2.1. LPDDR4
    • 4.8.2.2. LPDDR4X
  • 4.8.3. eMMC Support List
  • 4.8.4. NAND Flash Support List
  • 4.8.5. Camera Sensor Support List
  • 4.8.6. Wi-Fi/Bluetooth Support List
  • 4.8.7. PHY Support List
  • 4.8.8. BT1120 To HDMI List
  • 4.8.9. Audio Codec Support List
  • 4.8.10. IMU Support List
  • 4.8.11. MIPI DSI Support List
  • 4.8.12. 4G Support List