Programming Embedded Linux (Course 105 – 40 Hours)
Overview:
This course is intended for embedded systems developers taking their first steps with Linux as an embedded system platform, and provides them with the skills required for becoming a productive programmer in that environment. The curriculum includes building applications and device drivers with real time constraints and understanding the inner workings of the Linux system and its effects on system behavior.
The course is suitable for people planning to develop for embedded Linux platforms from any source, including “home made” Linux distributions or embedded Linux system vendors.
Course Objectives:
Create applications and device drivers for Embedded Linux environments, or to import such applications from systems using legacy RTOSes.
Who Should Attend:
Seasoned embedded systems developers wishing to become competent Linux Embedded systems developers.
Prerequisites:
Students should have a working knowledge with C programming language and basic knowledge with embedded systems.
Course Contents:
Introduction
- What is Linux
- Layers in a Linux system
- Linux vs. Legacy RTOS
Basic concepts
- Files and file system
- The shell
- Basic commands
- Processes
- Setting up networking
Application programming and the user space API
- Makefiles and the build environment
- Processes and threads
- Real time priorities
- Synchronization and IPC (mutex, condition variables, mailboxes, pipes, shared memory, Unix domain sockets and signals)
- Timers
- Memory mapping and locking
- Debugging applications: in process and using remote debugger
- Labs – using pipes, debugging
Linux Kernel
- Kernel overview
- History
- Versions
- Source code layout
- Good practices
- System call interface
Writing a simple kernel module
- A simple kernel module structure
- Implicit steps of compiling modules in Linux kernel version 2.6
- Using shell commands to manipulate modules
- The kernel log
- Using the printk function
- Passing parameters to the module
Memory Management
- Memory areas
- Memory page frames
- Requesting and releasing page frames
- Allocating contiguous virtual memory area
- The slab and slob allocators
- Memory caches and allocations
- Managing slabs
- Creating and destroying caches
- User space memory access
Implementing a character device file
- The VFS structure
- Initialization and termination
- Opening the device file
- IOCTL
- Implementing base operations
Debugging
- Kernel configuration for debugging
- printk
- KGDB
- Oops messages
Locking mechanisms
- Locking requirements
- Preemption
- Atomic bit operations
- Interrupt disabling
- Spin lock
- Semaphores
Linux Scheduler
- Process and thread
- Scheduling policies
- Priorities
- Kernel tasks
- task_struct structure
- SMP scheduling
Interrupt handling
- Hardware interrupt handling basics
- Interrupt handler and control
- Low level handling
- Wait queues technique
- Threaded interrupts
Bottom halves
- Differing work
- Using software interrupts
- Tasklets
- Timers & RTC
- Work queues
Network sub system overview
- The layer model
- Registration and un-registration
- Socket buffers, allocations and manipulations
- Network headers
- Packet reception
- Packet transmission
- NAPI