Linux Basic and Operational Framework Overview

Learning Linux, of course, is to start from the foundation of Linux, learn any technology, all the first solid foundation, then you will be the road behind the more and more smooth.

On Linux, I don't want to introduce too much here. As we all know, Linux is from 1991, a person named Linus wrote the first version of the Linux, that is, the version of 0.0.1, then about 8000 lines of such a code, then he joined the GNU, the organization is to create an open source public environment. The organization defines a protocol called the GPL, meaning that when it comes to the system, it must be open source, allowed to be modified and disseminated by others, but not for commercial use.

Now we get into the subject.

Before we remember when we gave the hardware power, it was the hardware in the boot process. In the past when there is no Linux operating system, we are not a power, we can go to a specific physical address to read the program we wrote, and then by this program to show what we want, whether it is printed out or do what. Then we have the operating system, a lot of things to the operating system to complete, we start the process has undergone a number of changes, first power, add electricity after the power through our bios, because after the completion of the power, our CPU will go to a specific physical address to fetch things, to take a BIOS, So the BIOS is based on the outside of our system, and then the BIOS went to a specific place, this place is the first address of our storage space, for our hard disk is the first sector of 0 Fu Dao, if the floppy disk boot is also the first sector. So go to the first sector to find the boot portal, this boot entry for Linux and then we find a boot program such as GRUB, the boot program will be based on the situation, because it knows where our operating system is, so it will load our operating system kernel. So there are a lot of steps after loading the kernel, so one of them is to mount our filesystem first, because with the filesystem we can go to the store. So this is the process. So what are we going to start after the system kernel is loaded? We also have to start our system services, and the system service is going to start our application so that our entire operating system is loaded.

So let's think about it, if we're going to design an operating system, how do we start designing it?

At least we think that, to do an operating system, we first, the operating system must know at least how to boot, so the boot has to have a portal, and secondly, the operating system to have at least access to our disk storage, which we call the file system, again, our operating system is not to have user management, this first not to say, The operating system may also be single-user. Operating system must run the program, then run the program is how to run, that is to load into the memory, then how to store it, we call the process. Of course, the concept of threading was born in the back of town. Second, we are in the storage process, is not the memory management. This is the core part of the operating system that we want to consider.

We can not design an operating system now, we choose an operating system, of course, choose our Ubuntu.

Ubuntu is a good open source, is an Android designated operating system, it is very convenient, Ubuntu development is fast, now Ubuntu has started to support the ARM architecture.

Ubuntu website: www.ubuntu.com

Before using Ubuntu and installing Ubuntu, let's take a look at the core architecture of the Linux operating system.

So what is the typical Linux operating system like?

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The main feature of Linux is that it has lower requirements for hardware because its graphical interface is designed to support its system program, which means that its kernel takes into account the graphics interface, and Linux does not have a graphical interface by default. Its graphical interface is simply the encapsulation of a protocol layer.

Recognize some versions of Ubuntu. Long-term represents a version of long-term maintenance.

Desktop

Server

There is also a cloud version

Installation of Ubuntu

1, pre-installation preparation work

(1) Hardware preparation: This is nothing to say, generally now as long as the computer can be run can be installed.

(2) VMware

(3) file system:

1. What is a file system?

Simply put, a file system is actually a way to store and organize your computer files and data. But we made it into a kind of system service. It's actually a software program.

2, file system general structure?

FAT32 NTFS

      EXT3     Swap

Let's imagine that we put a file on disk, that our Windows system does not have the concept of partitioning, Linux does not have. But Linux has the concept of booting, first we have to guide them, so we have to define the file system in the first to have a guide block, and secondly, we are for this disk, we are to store disk information, for example, our disk has How big, what is the size of each sector, this is called Master, super block. Third, we do not have a database to store data, This is our data block. We access the data fast because we have an index, and we have the inode.

3. Classification of file systems

Disk File system

NTFS, EXT3 (log file system)

Flash File system

Jffs2,yaffs

Database File system

Bfs,winfs

Network File system

Nfs

Virtual File system

VFS (Proc)

4, EXT3 SWAP

2. Install Ubuntu Desktop & Server

Linux files and file systems:

All documents

File properties

Linux file directory structure

File type (7 kinds)

General Documents-

Catalog File D

Link file L

Block Device B

Character Device C

Socket s

Pipe P (In fact, the exit of a program is written to another program's entrance)

Linux Basic and Operational Framework Overview