A hands-on course to enable you to write device drivers for hardware peripherals and devices in an embedded Linux system.
This course is available Live Online worldwide: View the Live Online full course description »
Standard Level - 4 days
Practical Embedded Linux Device Drivers is designed to give engineers the knowledge and skills to work confidently with all the components of the kernel to successfully develop device drivers.
Workshops comprise approximately 50% of this 4-day training course, with carefully designed hands-on exercises to reinforce learning. The workshops use devices from the 96Boards project, which provides a flexible learning environment that can replicate the individual projects attendees are facing. The 96Boards family includes devices from many of the major SoC Vendors, applicable to a wide range of different application contexts.
Why choose this particular course?
The ever-growing demand for connectivity and multimedia applications is resulting in embedded Linux systems driving increasingly complex devices. Developing custom device drivers for the Linux kernel can be a complex and difficult task, with an array of implementation choices available.
This course aims to reduce development time by demonstrating how the range of helper functions and mechanisms provided by the kernel can make custom device driver creation easier. Attendees
should come away from the course with a clear understanding of how to go about designing their
device driver and what kernel mechanisms they can make use of.
All the main kernel interfaces and structural elements are covered in the course. So as well as building confidence in working with the kernel components needed for a specific project, attendees also gain a sound understanding of the overall framework. This ensures the KnowHow delivered by the training will continue to be useful and valid for future device driver projects.
This course is suitable for engineers working in SoC, FPGA or custom board environments who want to get started quickly on developing custom kernel drivers. Although the course is primarily targeting
ARM based embedded systems it is still relevant for users of other commonly used embedded CPUs
such as MIPS, PowerPC etc.
- An understanding of the capabilities of the embedded Linux kernel and the techniques to work within it effectively
- The facilities and frameworks of the kernel and how they can be used to speed up driver development
- How to utilise the common patterns and data structures for different types of device driver.
- Completion of Developing with Embedded Linux training or equivalent working knowledge of using Linux as a host operating system
- Some familiarity with C programming is also necessary.
This is a hands-on training course and labs are conducted on a real target board (one of the
96Boards family of development platforms), with an ARM 32bit or 64bit CPU.
The course also takes advantage of the Grove Sensor Mezzanine board to enable attendees to develop and test drivers with real hardware.
Please contact the Doulos team to discuss your specific project and hardware requirements.
Doulos course materials are renowned for being the most comprehensive and user friendly available. Their unique style, content and coverage has made them sought after resources in their own right. The materials include fully indexed class notes creating a complete reference manual.
Introduction to Kernel Development
- Course introduction
- The kernel development process
- Module licensing
- Documentation and help
- Appendix: Git
- Exercises:
- Booting the target
- Working with a kernel source tree browser
Kernel & Module Building
- Configuring & compiling the kernel
- Structure of a kernel module
- Parameters, symbols and dependencies
- Use counts and referencing
- The kernel build system
- Code checking with Sparse
- Exercises:
- Building a driver out of tree
- Adding the driver to the kernel source tree
- Testing the driver with real hardware
Kernel Debugging
- Kernel symbols
- Oops and panics
- Printing debug statements
- JTAG
- KGDB/KDB
- Kernel tracing
- Exercises:
- Using warn and panic to debug a driver issue
- Tracing the kernel to analyze the performance of a driver
Device Driver Models
- Driver model data structures
- Platform devices and drivers
- kobjects & the SysFS
- Managed device resources
- Exercises:
- Adding the driver model structures and functions to a skeleton I2C client driver
- Testing the driver with real hardware
Working with Devicetrees
- Linux board support
- Devicetree compilation
- Devicetree syntax
- Parsing the devicetree
- Tools and debugging
- Exercises:
- Decompiling a devicetree blob to get the source
- Extending the devicetree to add information
- Parsing the devicetree data from a driver
User Space Interfaces
- Device types & files
- File operations
- Char devices
- DebugFS
- Exercises:
- Adding a character device interface to allow the driver to be configured from user space
- Writing a simple application to use an IOCTL to configure the driver
Hardware Interfaces
- Virtual and physical memory
- Allocating memory
- IO memory
- Direct Memory Access
- GPIO
- Exercises:
- Adding support for device control via a GPIO button
- Extending the devicetree to support this
- Registering interrupts
- Other HW IO frameworks (Regmap, Pinctrl)
- Exercises:
- Extending the driver to incorporate an interrupt handler
- Testing with the hardware
Data Structures and Concurrency
- Linked Lists
- Data Trees
- Kernel helper macros and functions
- Concurrency and locks
- Mutexes
- Spinlocks
- Exercises:
- Implementing a simple linked-list
- Resolving contention within a driver with a mutex
Scheduling and Managing Work
- Tasks and scheduling
- Wait queues and sleeping
- Timers
- Workqueues
- Exercise:
- Using timers and work queues to change how data is displayed by the driver
User Space Drivers
- Accessing Memory from User Space
- User Space IO
- LibGPIOd
- I2C & SPI IO
- FUSE, CUSE & BUSE
- Exercises:
- Implementing a simple devmen driver
- Using LibGPIOd to manage the same hardware
Frameworks and Subsystems
- ALSA
- DRM
- USB
- Industrial I/O
- Input Devices
- RemoteProc
- Firmware Loading
- Power Management
- Networking
- ‘Staging’ drivers
- Exercise:
- Reviewing how an existing driver uses kernel frameworks
