Guidelines for Developing a Nios II HAL Device Driver

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ID 683146
Date 6/12/2015
Public
Document Table of Contents
Document Table of Contents x
1. Guidelines for Developing a Nios II HAL Device Driver
1. Guidelines for Developing a Nios II HAL Device Driver x
1.1. Prerequisites for HAL Device Driver Development 1.2. Developing the HAL UART Device Driver 1.3. Debugging the bit_bang_uart Project 1.4. The BitBangUartTransmit() Function 1.5. The BitBangUartReceive() Function 1.6. Creating Device Hardware Access Macros 1.7. Staging the HAL Device Driver Development 1.8. Understanding the Hardware-Specific INSTANCE and INIT Macros 1.9. Integrating a New HAL Device Driver in the BSP 1.10. Understanding HAL Mutual Exclusion Resources 1.11. Overview of Debugging Tools for HAL Device Drivers 1.12. Debugging the HAL UART Device Driver 1.13. Conclusion 1.14. Document Revision History
1.1. Prerequisites for HAL Device Driver Development x
1.1.1. Using the HAL Architecture and Services 1.1.2. Software Requirements for the Driver Example 1.1.3. HAL Device Drivers and Components
1.2. Developing the HAL UART Device Driver x
1.2.1. Preparing the bit_bang_uart Application and hal_my_uart BSP 1.2.2. Preparing the my_uart_driver Device Driver 1.2.3. Configuring the Altera_Avalon_UART Component 1.2.4. Importing Projects 1.2.5. Verifying Software Functionality 1.2.6. Preview: Customizing the Design
1.2.6. Preview: Customizing the Design x
1.2.6.1. Making Software Modifications 1.2.6.2. Making Hardware Modifications
1.12. Debugging the HAL UART Device Driver x
1.12.1. Setting Breakpoints in the my_uart_driver Device Driver 1.12.2. Setting Watchpoints in the HAL UART Device Driver 1.12.3. Reducing Driver Code and Memory Footprint 1.12.4. Interrupt Latency and Determinism 1.12.5. Debugging with the Altera Logging Functions
1.12.3. Reducing Driver Code and Memory Footprint x
1.12.3.1. Using the Reduced Device Drivers API Option 1.12.3.2. Using the Lightweight Device Drivers API Option
1.12.5. Debugging with the Altera Logging Functions x
1.12.5.1. Altera Logging Usage 1.12.5.2. Altera Logging Example
1. Guidelines for Developing a Nios II HAL Device Driver

1.9. Integrating a New HAL Device Driver in the BSP

When you integrate a HAL device driver into a BSP, the following services are enabled:

  • Automatic initialization with the alt_sys_init() function for the HAL device drivers.

    alt_sys_init() is an automatically generated function. alt_sys_init() calls the INIT and INSTANCE macros for each component instance found in the hardware design that has a specific source code directory structure and set of file names. The directory structure for hardware components provided by Altera conforms to:

    <Altera installation>/ip/altera/sopc_builder_ip/<component_folder>

    The easiest option for a directory structure for your custom components conforms to:

    <my_design>/ip/<component_folder>

    Place the device driver source code files in a folder structure under <component_folder>. The file names conform to the following:

    • /inc/<component>_regs.h
    • /HAL/inc/<component>.h
    • /HAL/src/<component>.c

    This document uses the variable <Altera installation> to represent the location where the Altera Complete Design Suite is installed. On a Windows system, by default, that location is c:/altera/<version number>.

  • HAL device-class services can access any specific HAL device in that class. For example, Altera_Avalon_UART is a character-mode device, and so has access to higher level services such as buffer management. HAL software device drivers become available to the UNIX-style POSIX API for device functions such as open() and read().

For more information about adding device drivers using the Nios II SBT, refer to the "Integrating a Device Driver in the HAL" section of the "Developing Device Drivers for the Hardware Abstraction Layer" chapter of the Nios II Software Developer's Handbook.

For more information about how to integrate your own VHDL or Verilog HDL source code as a new HAL-compatible Qsys component, and for details about the Component Editor tool, refer to the "Creating Qsys Components" chapter of Volume 1: Design and Synthesis in the Quartus II Handbook.

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