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  How does computer boot up?

The whole boot process of computer can be summarized in 4 phases. 1. BIOS In the 70's  read-only memory(ROM) was invented. The boot program is written into ROM, the first thing the computer does is to read and execute this program when it's powered on. The program in this chip is called "Basic Input/Output System" (BIOS). 1.1 Power-On Self-Test The BIOS will first check whether the computer hardware can fulfill the basic conditions for booting up, this process is called Power-On Self-Test...

   Computer, boot, partition     2013-02-23 23:19:47

  Big file transfer in Linux

It's very common that we need to transfer files between two different hosts such as backups. It is also an very simple task, we can use scp or rsync to complete the task well. But what if the file is very big, it may take some time to transfer it. How can we transfer a big file with high speed? Here we propose one solution. Copy file If we copy one uncompressed file, then we should follow below steps: Compress data Send it to another host Uncompress the data Verify the data integrity This will...

   Linux, SCP,ZIP     2013-01-10 05:55:50

  Oracle released an urgent Java patch

On March 23, Oracle just released an urgent Java patch which is out of its normal update schedule. The security vulnerability is related to the Java SE running in web browsers on desktops. The CVE ID for this issue is CVE-2016-0636. With the unpatched Java, attackers can remotely exploit the target system without username and credentials. Successful exploits can impact the availability, integrity, and confidentiality of the user's system. When the user access pages containing malicious code...

   JAVA,SECURITY,ORACLE,NEWS     2016-03-25 08:39:59

  An experience of fixing a memory-corruption bug

During the last 4 months, I was disturbed by a memory-corruption bug, and this bug will cause program crash. Until last Monday, I found the root cause and fixed it. This debug process is a difficult but memorable experience, so I will share it in this article.   My program works as a SMS Hub. When it receives a SMS, it will allocate a structure in heap memory like this: typedef struct { ...... int *a[8]; ...... } info; After processing the SMS, the program will free the m...

   c, debug, unix, solaris, multi-thread     2014-05-04 03:52:43

  How Computers Boot Up

The previous post described motherboards and the memory map in Intel computers to set the scene for the initial phases of boot. Booting is an involved, hacky, multi-stage affair – fun stuff. Here’s an outline of the process: An outline of the boot sequence Things start rolling when you press the power button on the computer (no! do tell!). Once the motherboard is powered up it initializes its own firmware – the chipset and other tidbits – and tries to ...

   Computer,Boot-up,Rationale     2012-04-11 13:43:02

  Bash Shell Scripting - 10 Seconds Guide

This Bash shell scripting guide is not a detailed study but a quick reference to the BASH syntax. So lets begin... Common environment variables PATH - Sets the search path for any executable command. Similar to the PATH variable in MSDOS. HOME - Home directory of the user. MAIL - Contains the path to the location where mail addressed to the user is stored. IFS - Contains a string of characters which are used as word seperators in the command line. The string normally consists of the spac...

   Bash,Shell,Linux,Tutorial,10 seconds,Shortcut key     2012-02-28 08:05:41

  Learning Python as your first programming language

Python is a widely used general-purpose, high-level programming language Its design philosophy emphasizes code readability, and its syntax allows programmers to express concepts in fewer lines of code than would be possible in languages such as C. Python now becomes more and more popular and is now being used the first teaching language in some universities. Why would you like to learn Python as your first programming language? Below are the reasons. Python is a high-level language with dynami...

   Python,Advantage     2014-04-07 05:36:04

  Additional steps need to implement to setup shadow-boxV2 OPTEE on Raspberry PI

We followed the Shadow-box v2 project from the https://github.com/kkamagui/shadow-box-for-arm to set up the trustZone on Raspberry PI modeB to protect the Linux Kernel. But got a problem when doing the step: [3.6.5. Activate Shadow-Box for ARM and Start Secure Pi!] to create the hash for the memory area. The result is not shown. If you met the same problem, this is what I did to fix the problem on my PI: 1.1  When we do the step [3.5.1. Copy OP-TEE OS with Shadow-Box for ARM and N...

   HARDWARE,RASPBERRY PI     2019-05-20 08:52:55

  A guide on installing and setting up GitLab server on Ubuntu

GitHub, GitLab and BitBucket are the three most famous code hosting platform in the world. They have different features which allow teams or individuals to share code with others remotely. In case you want to build your own code hosting server so that you can host and share the code by yourself, you can install and set up your own server. In this post, we will walk you through a guide on installing and setting up GitLab server on Linux environment. gitlab is a web based code hosting tool which i...

   UBUNTU,TUTORIAL,GITLAB     2020-04-25 07:05:33

  Linus Torvalds’s Lessons on Software Development Management

If anyone knows the joys and sorrows of managing software development projects, it would be Linus Torvalds, creator of the world's most popular open-source software program: the Linux operating system. For more than 20 years, Torvalds has been directing thousands of developers to improve the open source OS. He and I sat down to talk about effective techniques in running large-scale distributed programming teams – and the things that don’t work, too.Torvalds says there are...

   Linux,Software development,Linus Tonalds     2011-09-28 09:16:02

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