PC Startup Phase
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Anonymous user
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flora -
flora -
Hello,
I’m posting here today because I want to create a small operating system on a physical medium (like a CD) similar to MS-DOS that includes a command terminal... My question is the following: I want to know the steps of the startup phase of a PC. I know it starts with the BIOS, which checks voltages for safety measures before launching anything, and then it looks for boot sectors on the physical medium chosen in its configuration... I want to learn more about this topic and see your opinions please; I'm very interested in it for my studies. Thank you in advance to everyone.
I’m posting here today because I want to create a small operating system on a physical medium (like a CD) similar to MS-DOS that includes a command terminal... My question is the following: I want to know the steps of the startup phase of a PC. I know it starts with the BIOS, which checks voltages for safety measures before launching anything, and then it looks for boot sectors on the physical medium chosen in its configuration... I want to learn more about this topic and see your opinions please; I'm very interested in it for my studies. Thank you in advance to everyone.
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2 réponses
A. A Machine Unlike Any Other
The laptop is, in its design, fundamentally identical to any desktop computer. Let's remember that modularity is the key phrase for computers. Thus, unlike all-in-one devices such as cameras, computers must maintain compatibility with a vast array of hardware both prior to and subsequent to their manufacturing date. This imperative necessitates a strong dissociation between the hardware and what is called the operating system (software). The latter must be able to adapt to many scenarios. As a result, a computer, unlike a television for instance, must go through a very long and complicated series of steps leading, ultimately, to its use. These steps mainly aim to ensure the smooth functioning of all the components of the machine in concert, via what is known as the "operating system." The most well-known operating system is, of course, Windows (in its various versions) published by the software giant: Microsoft.
laptopApple MacBook Pro and LED screen
Understanding this process is key to understanding the inner workings of a computer. Back to top
B. The First Step: the BIOS
windows home serverStarting WHS
Upon powering on a computer (laptop or desktop), a very basic component, but present in all computers, comes into play: it is a chip of read-only memory (memory that is written in such a way that even when powered off, its main content is preserved and accessible in a fraction of a second; it is also called "ROM") that contains a mini-software called "BIOS" (Basic Input/Output System).
This is the first link in the long chain that allows for "waking up" all the other components. The BIOS handles the basic recognition of the different parts and ensures their proper functioning within the overall structure of the computer. Because the proper execution of the recognition and activation steps of the hardware depends on the correct functioning of the computer.
The BIOS operates by default on its own and triggers, in a precise order (the same one, with rare exceptions), the steps. It also allows for a primary configuration of peripherals in a dedicated menu controlled via the keyboard. This functionality is mainly used today to resolve compatibility/recognition issues, hardware conflicts, or even to overclock certain components of the computer, such as the processor.
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C. The Software Relay to Start the System
Once all the components are properly started, the BIOS will "look for" the boot sector of the hard drive (sometimes referred to as the "boot sector"). This is the necessary step for starting the operating system (most commonly: Windows). From there, it is the software step that takes over and starts the operating system. With what that entails in terms of data transfer within the computer. We will return to this later, particularly regarding data transfers from the hard drive.
The part concerning the loading of the operating system essentially consists of loading pieces of software from the hard drive into the central RAM (the famous RAM). Of course, this is a stage where many other components come into play - such as the processor, which orchestrates this entire ballet. However, the objective remains that the operating system has the essential elements for its functioning in RAM. This is a sensitive stage, and many operational issues arise for the computer at this moment.
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D. Disk Booting While this step may seem long and complex, it has a significant advantage (in addition to ensuring total hardware compatibility) for anyone wishing to diagnose a potential problem at startup. Indeed, if the computer encounters a problem before the hard disk boot (or "boot sector"), it is a hardware issue; otherwise, the likelihood that it is a software issue is very high.
source: http://www.bestofmicro.com/guide/savoir-Ordinateur-portable,5-aWRHdWlkZT04JmlkQ2xhc3NldXI9MTQ=.html
The laptop is, in its design, fundamentally identical to any desktop computer. Let's remember that modularity is the key phrase for computers. Thus, unlike all-in-one devices such as cameras, computers must maintain compatibility with a vast array of hardware both prior to and subsequent to their manufacturing date. This imperative necessitates a strong dissociation between the hardware and what is called the operating system (software). The latter must be able to adapt to many scenarios. As a result, a computer, unlike a television for instance, must go through a very long and complicated series of steps leading, ultimately, to its use. These steps mainly aim to ensure the smooth functioning of all the components of the machine in concert, via what is known as the "operating system." The most well-known operating system is, of course, Windows (in its various versions) published by the software giant: Microsoft.
laptopApple MacBook Pro and LED screen
Understanding this process is key to understanding the inner workings of a computer. Back to top
B. The First Step: the BIOS
windows home serverStarting WHS
Upon powering on a computer (laptop or desktop), a very basic component, but present in all computers, comes into play: it is a chip of read-only memory (memory that is written in such a way that even when powered off, its main content is preserved and accessible in a fraction of a second; it is also called "ROM") that contains a mini-software called "BIOS" (Basic Input/Output System).
This is the first link in the long chain that allows for "waking up" all the other components. The BIOS handles the basic recognition of the different parts and ensures their proper functioning within the overall structure of the computer. Because the proper execution of the recognition and activation steps of the hardware depends on the correct functioning of the computer.
The BIOS operates by default on its own and triggers, in a precise order (the same one, with rare exceptions), the steps. It also allows for a primary configuration of peripherals in a dedicated menu controlled via the keyboard. This functionality is mainly used today to resolve compatibility/recognition issues, hardware conflicts, or even to overclock certain components of the computer, such as the processor.
Back to top
C. The Software Relay to Start the System
Once all the components are properly started, the BIOS will "look for" the boot sector of the hard drive (sometimes referred to as the "boot sector"). This is the necessary step for starting the operating system (most commonly: Windows). From there, it is the software step that takes over and starts the operating system. With what that entails in terms of data transfer within the computer. We will return to this later, particularly regarding data transfers from the hard drive.
The part concerning the loading of the operating system essentially consists of loading pieces of software from the hard drive into the central RAM (the famous RAM). Of course, this is a stage where many other components come into play - such as the processor, which orchestrates this entire ballet. However, the objective remains that the operating system has the essential elements for its functioning in RAM. This is a sensitive stage, and many operational issues arise for the computer at this moment.
Back to top
D. Disk Booting While this step may seem long and complex, it has a significant advantage (in addition to ensuring total hardware compatibility) for anyone wishing to diagnose a potential problem at startup. Indeed, if the computer encounters a problem before the hard disk boot (or "boot sector"), it is a hardware issue; otherwise, the likelihood that it is a software issue is very high.
source: http://www.bestofmicro.com/guide/savoir-Ordinateur-portable,5-aWRHdWlkZT04JmlkQ2xhc3NldXI9MTQ=.html
flora
Thank you, it helps me with an info assignment.