Operating system

Resource management
Interface between application and hardware
Multitasking
Memory management
Disk access
etc

Example

Linux
Microsoft Windows
OS X
FreeBSD
Android - on Linux kernel

Linux

Operating system
By Linus Torvalds
Originated in 1991
received support and assistance from volunteers who succeeded in creating a complete and functional kernel
Linux is Unix-like, but was developed without any Unix code

UNIX

Operating system
Assembly - c
OS X - Unix-based
What is the OS X new version based on ? i don't know!

Linux | Windows. (main difference)

Freedom | Restriction

Other difference

Full access vs Almost none access
Command line
Gratis vs $

Examples

Boot in any way
...

GNU/Linux

How it's started ?

When I started working at the MIT Artificial Intelligence Lab in 1971, I became part of a software-sharing community that had existed for many years.
ITS - assembly
As a member of this community, an AI Lab staff system hacker, my job was to improve this system.
We did not call our software “free software”, because that term did not yet exist; but that is what it was.
The collapse of the community
ITS were obsolete - 1980
The modern computers of the era, such as the VAX or the 68020, had their own operating systems, but none of them were free software

How it's started ?

sign a nondisclosure agreement even to get an executable copy.
This meant that the first step in using a computer was to promise not to help your neighbor

proprietary software, rule and idea

The rule made by the owners of proprietary software was, “If you share with your neighbor, you are a pirate. If you want any changes, beg us to make them.”
The idea that the proprietary software social system—the system that says you are not allowed to share or change software—is antisocial, that it is unethical, that it is simply wrong,

GNU/free operating system

what was needed first was an operating system
make the system compatible with Unix
GNU stands for: GNU's Not Unix

Stallman and GNU

In January 1984 I quit my job at MIT and began writing GNU software.
I therefore decided that my first program for the GNU Project would be a multilanguage, multiplatform compiler.

GNU Emacs

I concluded I would have to write a new compiler from scratch.
That new compiler is now known as GCC; none of the Pastel compiler is used in it, but I managed to adapt and use the C front end that I had written. But that was some years later; first, I worked on GNU Emacs.

GCC

GNU Compiler Collection

copyleft

Copyright

In 1980, the copyright law was extended to computer programs in the United States

Copyleft and the GNU GPL

The principal goal of GNU is to be free software.
So we needed to use distribution terms that would prevent GNU software from being turned into proprietary software. The method we use is called “copyleft”.
Copyleft uses copyright law, but flips it over to serve the opposite of its usual purpose: instead of a means for restricting a program, it becomes a means for keeping the program free.
The specific implementation of copyleft that we use for most GNU software is the GNU GPL.

General Public License

GNU

^* The Linux kernel

GNU's not Unix

What is the Free Software Movement ?

The free software movement campaigns to win for the users of computing the freedom that comes from free software. Free software puts its users in control of their own computing.

What is the Free Software

The freedom to run the program as you wish, for any purpose (freedom 0)
The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code - change it
The freedom to redistribute copies so you can help your neighbor (freedom 2). redistribute exact copy - you can sell it.
The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.

Free license

free software - released under a free license.

GNU GPL

Four freedom
Specific implementation of copyleft
the source code of the work must be made available under the same license
Gnu normally use the GNU General Public License (GNU GPL)

The Linux kernel is released under the GPLv2

FOSS

Free and open-source software
Contrast to proprietary software

Advantages

Security
Stability
Protecting privacy
Helps people
Public benefit

Brief history of Linux

In 1991, Linus Torvalds developed a Unix-compatible kernel and called it Linux.
received support and assistance from volunteers who succeeded in creating a complete and functional kernel
Linux is Unix-like, but was developed without any Unix code
It was proprietary at first - prohibited commercial redistribution
but in 1992, he made it free software - GPL
combining Linux with the not-quite-complete GNU system resulted in a complete free operating system
GNU + Linux = complete OS
GNU/Linux

Linux distribution

A Linux distribution (often called a distro for short) is an operating system made as a software collection based on the Linux kernel and, often, on a package management system
Number of linux distro

Debian
Ubuntu
Mint
openSUSE
Raspbian

distrowatch.com

Embedded system

^* multi platform

1. Telephone decoupling electronics (for ADSL).
2. Multicolour LED (displaying network status).
3. Single colour LED (displaying USB status).
4. Main processor
5. JTAG (Joint Test Action Group) test and programming port.
6. RAM, a single ESMT M12L64164A 8 MB chip.
7. Flash memory, obscured by sticker.
8. Power supply regulator.
9. Main power supply fuse.
10. Power connector.
11. Reset button.
12. Quartz crystal.
13. Ethernet port.
14. Ethernet transformer, Delta LF8505.
15. KS8721B ethernet PHY transmitter receiver.
16. USB port.
17. Telephone (RJ11) port.
18. Telephone connector fuses.

ADSL Modem/router

shell

Concept

Program/Environment - interface between user and kernel
The shell accepts human readable commands and translates them into something the kernel can read and process.

CLI example

bash
fish

GUI example

cinnamon
gnome
kde

FHS

Filesystem Hierarchy Standard

It is maintained by the Linux Foundation. The latest version is 3.0, released on 3 June 2015.
Currently it is only used by Linux distributions.
In the FHS all files and directories appear under the root directory /, even if they are stored on different physical or virtual devices.