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4.3. Driver Development Guide

This chapter aims to provide developers with a detailed guide on driver development, covering a range of driver debugging and configuration options, as well as driver-related features and debugging methods. Here is an overview of this chapter:

Driver development is a crucial part of embedded system development, which involves interaction and control with hardware devices, as well as integration with operating systems. This guide will lead developers to gain insight into the development, debugging and configuration processes of various drivers, thereby helping developers better understand and utilize hardware resources.

This chapter contains a series of sub-chains, each focusing on introducing a specific type of driver or related features to debug and configure methods. Specifically include:

-Configure uboot and kernel option parameters: Describes how to configure uboot and kernel option parameters to facilitate adaptation to target hardware devices and drivers.

-Debugging guide for various hardware interfaces: Debugging guide for various hardware interfaces including UART, GPIO, Pinctrl, IO-DOMAIN, ADC, SPI, SDIO, I2C, PWM, RTC, PMIC, LCD, Audio and other hardware interfaces, covering common driver development and debugging requirements. -Other functions and debug instructions: including Thermal system, self-start settings, custom system mirroring, low-power mode debugging and other functions and debug instructions, providing developers with more comprehensive development support.

By reading this chapter, developers will be able to gain an in-depth understanding of the development principles and debugging methods of various drivers, so as to carry out driver development work more efficiently and contribute to the stability and performance improvement of the system.

• 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