• Пожаловаться

Christopher Hallinan: Embedded Linux Primer: A Practical, Real-World Approach

Здесь есть возможность читать онлайн «Christopher Hallinan: Embedded Linux Primer: A Practical, Real-World Approach» весь текст электронной книги совершенно бесплатно (целиком полную версию). В некоторых случаях присутствует краткое содержание. год выпуска: 2006, ISBN: 978-0-13-167984-9, издательство: Prentice Hall, категория: ОС и Сети / на английском языке. Описание произведения, (предисловие) а так же отзывы посетителей доступны на портале. Библиотека «Либ Кат» — LibCat.ru создана для любителей полистать хорошую книжку и предлагает широкий выбор жанров:

любовные романы фантастика и фэнтези приключения детективы и триллеры эротика документальные научные юмористические анекдоты о бизнесе проза детские сказки о религиии новинки православные старинные про компьютеры программирование на английском домоводство поэзия

Выбрав категорию по душе Вы сможете найти действительно стоящие книги и насладиться погружением в мир воображения, прочувствовать переживания героев или узнать для себя что-то новое, совершить внутреннее открытие. Подробная информация для ознакомления по текущему запросу представлена ниже:

libcat.ru: книга без обложки
  • Название:
    Embedded Linux Primer: A Practical, Real-World Approach
  • Автор:
  • Издательство:
    Prentice Hall
  • Жанр:
  • Год:
    2006
  • Язык:
    Английский
  • ISBN:
    978-0-13-167984-9
  • Рейтинг книги:
    4 / 5
  • Избранное:
    Добавить книгу в избранное
  • Ваша оценка:
    • 80
    • 1
    • 2
    • 3
    • 4
    • 5

Embedded Linux Primer: A Practical, Real-World Approach: краткое содержание, описание и аннотация

Предлагаем к чтению аннотацию, описание, краткое содержание или предисловие (зависит от того, что написал сам автор книги «Embedded Linux Primer: A Practical, Real-World Approach»). Если вы не нашли необходимую информацию о книге — напишите в комментариях, мы постараемся отыскать её.

Comprehensive Real-World Guidance for Every Embedded Developer and Engineer This book brings together indispensable knowledge for building efficient, high-value, Linux-based embedded products: information that has never been assembled in one place before. Drawing on years of experience as an embedded Linux consultant and field application engineer, Christopher Hallinan offers solutions for the specific technical issues you're most likely to face, demonstrates how to build an effective embedded Linux environment, and shows how to use it as productively as possible. Hallinan begins by touring a typical Linux-based embedded system, introducing key concepts and components, and calling attention to differences between Linux and traditional embedded environments. Writing from the embedded developer's viewpoint, he thoroughly addresses issues ranging from kernel building and initialization to bootloaders, device drivers to file systems. Hallinan thoroughly covers the increasingly popular BusyBox utilities; presents a step-by-step walkthrough of porting Linux to custom boards; and introduces real-time configuration via CONFIG_RT--one of today's most exciting developments in embedded Linux. You'll find especially detailed coverage of using development tools to analyze and debug embedded systems--including the art of kernel debugging. • Compare leading embedded Linux processors • Understand the details of the Linux kernel initialization process • Learn about the special role of bootloaders in embedded Linux systems, with specific emphasis on U-Boot • Use embedded Linux file systems, including JFFS2--with detailed guidelines for building Flash-resident file system images • Understand the Memory Technology Devices subsystem for flash (and other) memory devices • Master gdb, KGDB, and hardware JTAG debugging • Learn many tips and techniques for debugging within the Linux kernel • Maximize your productivity in cross-development environments • Prepare your entire development environment, including TFTP, DHCP, and NFS target servers • Configure, build, and initialize BusyBox to support your unique requirements

Christopher Hallinan: другие книги автора


Кто написал Embedded Linux Primer: A Practical, Real-World Approach? Узнайте фамилию, как зовут автора книги и список всех его произведений по сериям.

Embedded Linux Primer: A Practical, Real-World Approach — читать онлайн бесплатно полную книгу (весь текст) целиком

Ниже представлен текст книги, разбитый по страницам. Система сохранения места последней прочитанной страницы, позволяет с удобством читать онлайн бесплатно книгу «Embedded Linux Primer: A Practical, Real-World Approach», без необходимости каждый раз заново искать на чём Вы остановились. Поставьте закладку, и сможете в любой момент перейти на страницу, на которой закончили чтение.

Шрифт:

Сбросить

Интервал:

Закладка:

Сделать

• Initializes critical hardware components, such as the SDRAM controller, I/O controllers, and graphics controllers

• Initializes system memory in preparation for passing control to the operating system

• Allocates system resources such as memory and interrupt circuits to peripheral controllers, as necessary

• Provides a mechanism for locating and loading your operating system image

• Loads and passes control to the operating system, passing any required startup information that might be required, such as total memory size clock rates, serial port speeds and other low-level hardware specific configuration data

This is a very simplified summary of the tasks that a typical embedded-system bootloader performs. The important point to remember is this: If your embedded system will be based on a custom-designed platform, these bootloader functions must be supplied by you, the system designer. If your embedded system is based on a commercial off-the-shelf (COTS) platform such as an ATCA chassis,[4] typically the bootloader (and often the Linux kernel) is included on the board. Chapter 7 discusses bootloaders in detail.

2.2. Anatomy of an Embedded System

Figure 2-1 shows a block diagram of a typical embedded system. This is a very simple example of a high-level hardware architecture that might be found in a wireless access point. The system is centered on a 32-bit RISC processor. Flash memory is used for nonvolatile program and data storage. Main memory is synchronous dynamic random-access memory (SDRAM) and might contain anywhere from a few megabytes to hundreds of megabytes, depending on the application. A real-time clock module, often backed up by battery, keeps the time of day (calendar/wall clock, including date). This example includes an Ethernet and USB interface, as well as a serial port for console access via RS-232. The 802.11 chipset implements the wireless modem function.

Figure 2-1. Example embedded system

Фото

Often the processor in an embedded system performs many functions beyond the traditional CPU. The hypothetical processor in Figure 2-1 contains an integrated UART for a serial interface, and integrated USB and Ethernet controllers. Many processors contain integrated peripherals. We look at several examples of integrated processors in Chapter 3, "Processor Basics."

2.2.1. Typical Embedded Linux Setup

Often the first question posed by the newcomer to embedded Linux is, just what does one need to begin development? To answer that question, we look at a typical embedded Linux development setup (see Figure 2-2).

Figure 2-2. Embedded Linux development setup

Фото

Here we show a very common arrangement. We have a host development system, running your favorite desktop Linux distribution, such as Red Hat or SuSE or Debian Linux. Our embedded Linux target board is connected to the development host via an RS-232 serial cable. We plug the target board's Ethernet interface into a local Ethernet hub or switch, to which our development host is also attached via Ethernet. The development host contains your development tools and utilities along with target filesnormally obtained from an embedded Linux distribution.

For this example, our primary connection to the embedded Linux target is via the RS-232 connection. A serial terminal program is used to communicate with the target board. Minicom is one of the most commonly used serial terminal applications and is available on virtually all desktop Linux distributions.

2.2.2. Starting the Target Board

When power is first applied, a bootloader supplied with your target board takes immediate control of the processor. It performs some very low-level hardware initialization, including processor and memory setup, initialization of the UART controlling the serial port, and initialization of the Ethernet controller. Listing 2-1 displays the characters received from the serial port, resulting from power being applied to the target. For this example, we have chosen a target board from AMCC, the PowerPC 440EP Evaluation board nicknamed Yosemite. This is basically a reference design containing the AMCC 440EP embedded processor. It ships from AMCC with the U-Boot bootloader preinstalled.

Listing 2-1. Initial Bootloader Serial Output

U-Boot 1.1.4 (Mar 18 2006 - 20:36:11)


AMCC PowerPC 440EP Rev. B

Board: Yosemite - AMCC PPC440EP Evaluation Board

         VCO: 1066 MHz

         CPU: 533 MHz

         PLB: 133 MHz

         OPB: 66 MHz

         EPB: 66 MHz

         PCI: 66 MHz

I2C:   ready

DRAM:  256 MB

FLASH: 64 MB

PCI:   Bus Dev VenId DevId Class Int

In:    serial

Out:   serial

Err:   serial

Net:   ppc_4xx_eth0, ppc_4xx_eth1


=>

2.3. Storage Considerations

One of the most challenging aspects of embedded systems is that most embedded systems have limited physical resources. Although the Pentium 4 machine on your desktop might have 180GB of hard drive space, it is not uncommon to find embedded systems with a fraction of that amount. In many cases, the hard drive is typically replaced by smaller and less expensive nonvolatile storage devices. Hard drives are bulky, have rotating parts, are sensitive to physical shock, and require multiple power supply voltages, which makes them unsuitable for many embedded systems.

2.3.1. Flash Memory

Nearly everyone is familiar with CompactFlash modules[5] used in a wide variety of consumer devices, such as digital cameras and PDAs (both great examples of embedded systems). These modules can be thought of as solid-state hard drives, capable of storing many megabytesand even gigabytesof data in a tiny footprint. They contain no moving parts, are relatively rugged, and operate on a single common power supply voltage.

Several manufacturers of Flash memory exist. Flash memory comes in a variety of physical packages and capacities. It is not uncommon to see embedded systems with as little as 1MB or 2MB of nonvolatile storage. More typical storage requirements for embedded Linux systems range from 4MB to 256MB or more. An increasing number of embedded Linux systems have nonvolatile storage into the gigabyte range.

Flash memory can be written to and erased under software control. Although hard drive technology remains the fastest writable media, Flash writing and erasing speeds have improved considerably over the course of time, though flash write and erase time is still considerably slower. Some fundamental differences exist between hard drive and Flash memory technology that you must understand to properly use the technology.

Flash memory is divided into relatively large erasable units, referred to as erase blocks. One of the defining characteristics of Flash memory is the way in which data in Flash is written and erased. In a typical Flash memory chip, data can be changed from a binary 1 to a binary 0 under software control, 1 bit/word at a time, but to change a bit from a zero back to a one, an entire block must be erased. Blocks are often called erase blocks for this reason.

Читать дальше

Шрифт:

Сбросить

Интервал:

Закладка:

Сделать

Похожие книги на «Embedded Linux Primer: A Practical, Real-World Approach»

Представляем Вашему вниманию похожие книги на «Embedded Linux Primer: A Practical, Real-World Approach» списком для выбора. Мы отобрали схожую по названию и смыслу литературу в надежде предоставить читателям больше вариантов отыскать новые, интересные, ещё не прочитанные произведения.


Отзывы о книге «Embedded Linux Primer: A Practical, Real-World Approach»

Обсуждение, отзывы о книге «Embedded Linux Primer: A Practical, Real-World Approach» и просто собственные мнения читателей. Оставьте ваши комментарии, напишите, что Вы думаете о произведении, его смысле или главных героях. Укажите что конкретно понравилось, а что нет, и почему Вы так считаете.