Uclinux Course Day 1

7/18/2019 Uclinux Course Day 1

1/12

1

uClinux course


2/12

Author: D L Johnson

Overview

Day 1

+ Survey of embedded operating systems - why uclinux?

+ The uclinux environment - the directory structure

Day 2

+ Using the configuration tools for the kernel and user applications

+ Adding user application to uClinux

Day 3

+ The cross compiling tool chain (gcc, as, ld, objdump, objcopy)

+ Ripping apart a "Hello World" - it's not a simple program!+ Memory architecture of the arm7tdmi processor - configuring uclinux for the

arm

Day 4

+ To "Boot loader" or not to "Boot loader"

+ Hardware access and device drivers

Day 5+ Debugging applicatgions with gdb

+ Downloading applications to the development kit using JTAG

+ Running bluetooth stacks on uclinux


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uClinux course

Day 1 of 5

Survey of embedded operating systems why uclinux?


4/12

Author: D L Johnson

uClinux day 1 of 5 Why uclinux

Why use an operating system

+ Memory management

+ Thread/process management

+ Drivers for input devices such as keyboards, mouse

+ Drivers for output devices such as screens, sound, printers

+ File system management on disks/flash memory

What is an embedded operating system

+ Runs on small inexpensive microprocessors

+ Runs in memory restricted environments even without MMU

+ Often no hard drive or disk drive

uses flash based disk

+ Can run without any screen output or keyboard/mouse input


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What embedded operating systems are available

+Vxworks $$ - pathfinder on Mars (RTOS)

+ Nucleus $$

+ QNX $$ (POSIX, RTOS)

+ DOS $$

+ How grown operating systems

+ Redhat ecos (POSIX, uITRON)

+ uClinux




Until recently developers of small embedded systems

based on microprocessors lacking MMU could not take

advantage of Linux

uCliknux was started by Arcturus networks in 1997

Implements Linux on MMU-less processors

Publicly released back into open source as alternative OS

for the Palm Pilot in February 1998

Ported to ARM, MIPS, SPARC, Hitachi SH, Motorolla

coldfire

Mature, robust operating system

Supports large number of devices, filesystems andnetwork protocols

Large open source community adding features




Large number of applications exist for Linux which

require little or no proting

Vert low cost

no royalties

uClinux may well represent the world's first, most mature,

and most commercially successful embedded Linux

distribution




Devices that use uClinux



uClinux day 1 of 5 uClinux environment

Kernel UserlanduClibc

Cross compiler and linker

Image.bin

li d f li i


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1Author: D L Johnson


Cli d 1 f 5 Cli i t


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Configure scripts e.g. menuconfig and xconfig

Glibc source code

Binary images of uclinux ready to load onto hardware

uC-libc source code

Linux-2.4.x kernel source code

Linux-2.0.x kernel source code

Documentation on e.g. adding platform and user apps

uClibc source code

Userland contains all user applications

Romfs contains directory structure of uClinux

Contains all architecture settings such as memory layouts

Driver source code for all peripherals

Uclinux Course Day 1

Documents

Transcript of Uclinux Course Day 1