Kernel Internals. Course Duration: 5 days. Pre-Requisites : Course Objective: Course Outline

Transcription

1 Course Duration: 5 days Pre-Requisites : Good C programming skills. Required knowledge Linux as a User Course Objective: To get Kernel and User Space of Linux and related programming Linux Advance Programming To get real-world exposure to embedded Linux using different demo boards ARM for Labs To develop an application to run on an embedded Linux system To understand what is required to set-up a Linux cross development environment To understand the different approaches to making Linux realtime Delegates will learn: How to configure a standard Linux kernel for use in a cross development system. The steps to write, compile, download and debug an embedded Linux application with real hardware. How threaded applications fit into Linux. How drivers work in x86 and embedded environment. Course Outline Kernel Internals Introduction to Kernel - History of Linux - Types of Kernel - The Linux kernel - Kernel Facilities 1 page out of 10

2 - Kernel Architecture - Kernel Version Numbers - Configure, Compile Kernel The File System - Virtual File system & its role - Files associated with a process - System Calls Process management - Process Defined - Process Descriptor Structures in the kernel - Process States - Process Scheduling - Process Creation - System calls related to process management Memory Management - malloc, calloc, alloca, free - Demand Paging defined - Process Organization in Memory - Virtual Memory Management - Address Translation and page fault handling - Buddy System Algorithm - Slab Allocator - Swapping Memory Areas - Memory Mapping - Block Device Caching Interrupts - Conceptual Understanding About Interrupts Interrupt Handlers Softirqs Tasklets Work Queues Device Drivers Conceptual understanding Character Device Drivers Block Device Driers Network Device Drivers Kernel Configuration and Compilation - Kernel Building System - Patching the Kernel - Kernel Configuration - Compiling the Linux Kernel 2 page out of 10

3 Kernel Parameters - Build-Time Parameters - Boot-Time Parameters - Run-Time Parameters Boot Process - understanding Power ON to login prompt process - BIOS Level - Boot Loader Setup, startup_32 functions Available Bootloaders GRUB, UBoot, etc. Role of a Bootloader Bootloader Phase - Kernel Initialisation Phase The start_kernel() function - System Initialisation Phase Linux Advanced Programming Understanding Runlevels Various initialization scripts & customizing them Kernel Command-Line Boot Parameters Arguments, the environment, and popular system functions - Arguments to a program. - Retrieving information from the environment. - Discovering the date and time - Getting system information. File I/O - Library functions and system calls for I/O - Getting file status information with stat() - Processing directories and directory entries. Shell Commands & Shell Scripting - Basic Shell commands - Bash Shell Essentials Creating Makefiles - Makefile basics - Creating make files for single or multiple source files project Creating Lilbraries - Creating Static Library - Creating Shared Library Multi Process Programming - Creating child processes - fork(). vfork(), exec() - Parent synchronization with child 3 page out of 10

4 Multi Thread Programming - Creating multiple threads - Parent synchronization with other Threads Inter Process Communication - Pipes, FIFO's, - Signals - System-V IPC's - Message queues - Shared memory - Semaphores Introduction to Sockets - An Overview - System calls related to TCP and UDP sockets - Using Wireshark etc tool for network sniffing Network Programming - TCP Server Client Programming - UDP Server Client Programming Programming & Debugging Tools - Debugging and Analysis Tools - strace : Tracing System calls - ltrace : Tracing Library calls - Using gdb and ddd utilities - Core Dump Analysis etc Code checkers, memory checkers, profilers Embedded Linux System Development Introduction to Embedded Linux - What is Embedded System? - Anatomy of an Embedded System - Why Linux? - Is Linux Real-Time Enough? - The Status of Embedded Linux Today - Which Embedded Linux Distribution to Choose? - Embedded Linux Architecture Basic requirements for Embedded Linux Product Development - The four basic elements: toolchain, bootloader, kernel, root file system - Configuration, compilation and cross-compiling 4 page out of 10

5 Building Development Environment ( Obisense ) - Toolchain installation - Cross compilation using Toolchain Target & Host Setup Setting Up Networking Services - Network Settings Static and Dynamic IP addresses Subnet mask - loading files using TFTP, HTTP, FTP etc. Bootloader commands and usage - Getting familiar with bootloader commands - Downloading kernel images and RootFS on Target board. Loading RootFS in Platfrom by various techniques - - Configuring TFTP and downloading kernel image over TFTP. - Configuring NFS and using rootfs over NFS. - Using SD-Card for rootfs. - Using USB for rootfs. Building an Embedded File System from Scratch - - Creating a minimal root file-system using Busybox - Creating a RAM disk image Intro to Building Own Embedded Linux Distribution - - Buildroot - Scratchbox - OpenEmbedded - Crosstool - Angstrom Narcissus Kernel Configuration and Compilation - Kernel Building System - Patching the Kernel - Kernel Configuration for Embedded Systems Settings (Porting) - Cross-compiling the Linux Kernel - Booting Linux - The Linux boot sequence - boot-loaders : U-boot - System Initialization Scripts - Bring up X11 (X-Windows) on Embedded Platform (GUI) - Loading various RootFS (Distributions) in platform Angstrom, Ubuntu, Fedora etc. RootFS 5 page out of 10

6 - Board Bring-ups of following Embedded Linux Hardware Platforms Different Boards Used for differentiation and initialization Friendly ARM 2440 (main board used) Raspberry Pi (intro and demonstration) 6 page out of 10

7 Beaglebone Black (intro and demonstration) - Embedded Apps & Device Drivers Labs on Embedded Linux Boards Writing Device Drivers & Applications for Embedded Platforms Accessing GPIOs Interfacing LED, Switch, Camera, Seven Segment Display Installing Web Server on Embedded Platform Porting Issues in Linux Linux Porting Issues Kernel Compilation and Architecture Specific Issues Cross Compilation Building Application in to Kernel Other issues Linux Device Drivers An introduction to device drivers - User space vs Kernel space - Kernel Architecture or Model - Splitting the kernel - Kernel modules - Kernel Module vs Applications - Role of the Device Drivers - Classes of devices and modules 7 page out of 10

8 Kernel Module Programming Basics - Modules Defined - Data Type in the Kernel - Version dependency - Building and Running Modules - Types of Modules in the kernel - Writing Your first kernel module - Module Related Commands - Statically linked vs Dynamically linked drivers/modules - The kernel symbol table - Exporting symbols from modules - Module Parameters for above mentioned topics Kernel Debugging Techniques - Kernel Debugging: dmesg, printk for above mentioned topics Accessing Hardware Mechanisms - System Memory - Device Memory - I/O Ports - I/O ports vs. memory mapping - Allocating and mapping I/O space - Functions for reading and writing I/O ports - Side effects and compiler optimization - Accessing hardware from User Space - Example: the Parallel Port - Driver example - Barriers - User-Mode Access to Devices open, close, read, write ioctl ioperm, iopl, inb, outb mmap, munmap The proc file system programming - Using /proc - Creating proc file system entries - Registration - Reading from /proc - Writing to /proc Hardware and Interrupt Handling - Installing and implementing an interrupt handler 8 page out of 10

9 - Restrictions of kernel code running in interrupt context - IRQs & their Registration - IRQ Handling & Control - Top & Bottom Halves - Enabling and Disabling Interrupts Tasklets and Bottom halves - Task queues Kernel Threads Sleep and wakeup (wait queues) Memory Management - Allocating Memory - Accessing Memory - Get Some Space (kmalloc()), kfree(), various flags - Get Some Pages (get_free_page()) - Get Some Virtual Memory - vmalloc() - Get Some Boot-time Space Concurrency and Race Conditions - Combating Race Conditions - Atomic Operations - Semaphores - Spin Locks Time, Delays and Deferred Work - Kernel Timers - Timer handling - HZ and Jiffies - Time of Day - Delayed Execution - Kernel Timers - Current time The Linux Device Model Character Device Drivers - Registering a character device driver - The file structure - Major and minor numbers - Character Device Methods open(), release(), read(), write() - Data Transfers between User Process and Driver 9 page out of 10

10 copy_from_user(), copy_to_user() - Making a Device File - Memory Access in Kernel Space - Programming with ioctl( ), mmap() - devfs / lseek /ioctl Writing various Character Drivers - Memory Based Driver - IO PORT (Hardware) Based Driver Programming with ioctl( ) - writing device driver with ioctl() - Adding ioctl s in an existing device driver Netlink socket interface - point to point, multicast and broadcast - UDP, TCP and Raw sockets - Writed kernel module and userspace applilcations using Netlink sockets Network Drivers - The net_device structure in detail - Packet transmission - Packet reception - Simulating a network device Adding a Driver to the Kernel Tree Sample Hardware based device driver projects * * * * * * * * 10 page out of 10