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

1.1.1. Using the HAL Architecture and Services

The HAL application programming interface (API) provides an interface to hardware similar to a portable operating system interface for unix (POSIX). This interface abstracts the hardware details from upper-level clients of the HAL, such as operating systems, networking stacks, or Nios II applications. The HAL provides a variety of generic device classes, including character-mode, file subsystem, Ethernet, timestamp and system timers, direct memory access (DMA), and flash memory. The Altera_Avalon_UART is a member of the character-mode class of HAL devices. The HAL has an API for character-mode class devices, which you can use to manipulate the Altera_Avalon_UART. Mutual exclusion resources are available, provided either by MicroC/OS-II (if present) or by the HAL. These services include semaphores and event flags. When the HAL device driver makes calls to these resources, the calls are simply translated to non-operations when the multi-threading services are not available.

For additional information about HAL services, refer to the "Developing Programs Using the Hardware Abstraction Layer" chapter in the Nios II Software Developer's Handbook.

For additional information about the HAL API, refer to the "HAL API Reference" chapter in the Nios II Software Developer's Handbook.

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