Basics of Operating Systems Definition – Generations of Operating systems – Types of Operating Systems, OS Service, System Calls, OS structure: Layered, Monolithic, Microkernel Operating Systems – Concept of Virtual Machine
Basics of Operating Systems Definition – Generations of Operating systems – Types of Operating Systems, OS Service, System Calls, OS structure: Layered, Monolithic, Microkernel Operating Systems – Concept of Virtual Machine
Installation of Windows & Linux operating systemSathishnkl561998
This presentation tells some details on installing an operating system in the computer. I assure this things will help you to get some knowledge about the installation of the operating systems.
Computer Application- Booting and Start-up Sequence
,booting and start-up sequence ,computer application ,booting required ,boot process occurs ,bios interaction ,bios setup ,tasks performed at boot up ,booting and rom ,secondary boot loaders ,grub loader ,dos
Processes description and process control.Ahsan Rahim
My Fiverr Profile: https://www.fiverr.com/ahsanrahim786
Click to download more Books: http://appsdisaster.blogspot.com/
Process description and process control block in operating system. It includes Process Control Block, Two-states Process model & Five-state process models,
Presentation is about Traditional Two Pass Compiler architecture done by 4th year Computer Science and Technology(special) undergraduates at Uva Wellassa University, Sri Lanka
This PPT shares some information on what is booting process and different stages in it. Importance of BIOS and BootROM. Steps involved for loading kernel into RAM. What is the importance of init RAM disk (initrd), when 1st user space application is started and who will create init process.
Installation of Windows & Linux operating systemSathishnkl561998
This presentation tells some details on installing an operating system in the computer. I assure this things will help you to get some knowledge about the installation of the operating systems.
Computer Application- Booting and Start-up Sequence
,booting and start-up sequence ,computer application ,booting required ,boot process occurs ,bios interaction ,bios setup ,tasks performed at boot up ,booting and rom ,secondary boot loaders ,grub loader ,dos
Processes description and process control.Ahsan Rahim
My Fiverr Profile: https://www.fiverr.com/ahsanrahim786
Click to download more Books: http://appsdisaster.blogspot.com/
Process description and process control block in operating system. It includes Process Control Block, Two-states Process model & Five-state process models,
Presentation is about Traditional Two Pass Compiler architecture done by 4th year Computer Science and Technology(special) undergraduates at Uva Wellassa University, Sri Lanka
This PPT shares some information on what is booting process and different stages in it. Importance of BIOS and BootROM. Steps involved for loading kernel into RAM. What is the importance of init RAM disk (initrd), when 1st user space application is started and who will create init process.
An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is an essential component of the system software in a computer system. Application programs usually require an operating system to function.
Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.
For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware,[1][2] although the application code is usually executed directly by the hardware and will frequently make a system call to an OS function or be interrupted by it. Operating systems can be found on almost any device that contains a computer—from cellular phones and video game consoles to supercomputers and web servers.
Examples of popular modern operating systems include Android, BSD, iOS, Linux, OS X, QNX, Microsoft Windows,[3] Windows Phone, and IBM z/OS. All these, except Windows, Windows Phone and z/OS, share roots in UNIX.
Presentation Regarding functions of operating systems and their working and other information regarding their uses and types. Useful for Students and other for knowing better about them.
Pleases Send Your Valuable Comments regarding it
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...
Booting
1. Course PresentationCourse Presentation
Booting of aBooting of a
Computer SystemComputer System
Presentation By:Presentation By: Shehrevar DavierwalaShehrevar Davierwala
Contact:Contact: 96736515469673651546
Email:Email: shehrevar@live.comshehrevar@live.com
2. Course Presentation
Why is Booting Required ?Why is Booting Required ?
► Hardware doesn’t know where the operatingHardware doesn’t know where the operating
system resides and how to load it.system resides and how to load it.
► Need a special program to do this job –Need a special program to do this job – BootstrapBootstrap
loader.loader.
E.g. BIOS – Boot Input Output System.E.g. BIOS – Boot Input Output System.
► Bootstrap loader locates the kernel, loads it intoBootstrap loader locates the kernel, loads it into
main memory and starts its execution.main memory and starts its execution.
► In some systems, a simple bootstrap loaderIn some systems, a simple bootstrap loader
fetches a more complex boot program from disk,fetches a more complex boot program from disk,
which in turn loads the kernel.which in turn loads the kernel.
3. Course Presentation
How Boot process occurs ?How Boot process occurs ?
►Reset event on CPU (power up, reboot)Reset event on CPU (power up, reboot)
causes instruction register to be loaded withcauses instruction register to be loaded with
a predefined memory location. It contains aa predefined memory location. It contains a
jump instruction that transfers execution tojump instruction that transfers execution to
the location of Bootstrap program.the location of Bootstrap program.
►This program is form of ROM, since RAM isThis program is form of ROM, since RAM is
in unknown state at system startup. ROM isin unknown state at system startup. ROM is
convenient as it needs no initialization andconvenient as it needs no initialization and
can’t be affected by virus.can’t be affected by virus.
5. Course Presentation
Tasks performed at boot upTasks performed at boot up
► Run diagnostics to determine the state ofRun diagnostics to determine the state of
machine. If diagnostics pass, booting continues.machine. If diagnostics pass, booting continues.
► Runs aRuns a Power-On Self TestPower-On Self Test ((POSTPOST) to check the) to check the
devices that the computer will rely on, aredevices that the computer will rely on, are
functioning.functioning.
► BIOS goes through a preconfigured list of devicesBIOS goes through a preconfigured list of devices
until it finds one that is bootable. If it finds no suchuntil it finds one that is bootable. If it finds no such
device, an error is given and the boot processdevice, an error is given and the boot process
stops.stops.
► Initializes CPU registers, device controllers andInitializes CPU registers, device controllers and
contents of the main memory. After this, it loadscontents of the main memory. After this, it loads
the OS.the OS.
8. Course Presentation
Tasks performed at boot up (Contd)Tasks performed at boot up (Contd)
► On finding a bootable device, the BIOS loads andOn finding a bootable device, the BIOS loads and
executes itsexecutes its boot sectorboot sector. In the case of a hard. In the case of a hard
drive, this is referred to as thedrive, this is referred to as the master boot recordmaster boot record
((MBRMBR) and is often not OS specific.) and is often not OS specific.
► The MBR code checks theThe MBR code checks the partition tablepartition table for anfor an
active partition. If one is found, the MBR codeactive partition. If one is found, the MBR code
loads that partition'sloads that partition's boot sectorboot sector and executes it.and executes it.
► The boot sector is oftenThe boot sector is often operating systemoperating system specific,specific,
however in most operating systems its mainhowever in most operating systems its main
function is to load and execute afunction is to load and execute a kernelkernel, which, which
continues startup.continues startup.
9. Course Presentation
Secondary Boot LoadersSecondary Boot Loaders
► If there is no active partition or the active partition'sIf there is no active partition or the active partition's
boot sector is invalid, the MBR may load aboot sector is invalid, the MBR may load a
secondary boot loader and pass control to it andsecondary boot loader and pass control to it and
this secondary boot loader will select a partitionthis secondary boot loader will select a partition
(often via user input) and load its boot sector.(often via user input) and load its boot sector.
► Examples of secondary boot loadersExamples of secondary boot loaders
GRUB – GRand Unified BootloaderGRUB – GRand Unified Bootloader
LILO – LInux LOaderLILO – LInux LOader
NTLDR – NT LoaderNTLDR – NT Loader
11. Course Presentation
Booting and ROMBooting and ROM
►System such as cellular phones, PDAs andSystem such as cellular phones, PDAs and
game consoles stores entire OS on ROM.game consoles stores entire OS on ROM.
Done only for small OS, simple supportingDone only for small OS, simple supporting
hardware, and rugged operation.hardware, and rugged operation.
►Changing bootstrap code would requireChanging bootstrap code would require
changing ROM chips.changing ROM chips.
EPROM – Erasable Programmable ROM.EPROM – Erasable Programmable ROM.
►Code execution in ROM is slower. Copied toCode execution in ROM is slower. Copied to
RAM for faster execution.RAM for faster execution.
12. Course Presentation
Example : DOSExample : DOS
► After identifying the location of boot files, BIOS looks at the first sectorAfter identifying the location of boot files, BIOS looks at the first sector
(512 bytes) and copies information to specific location in RAM (7C00H)(512 bytes) and copies information to specific location in RAM (7C00H)
-- Boot RecordBoot Record..
► Control passes from BIOS to a program residing in the boot record.Control passes from BIOS to a program residing in the boot record.
► Boot record loads the initial system file into RAM. For DOS, it isBoot record loads the initial system file into RAM. For DOS, it is
IO.SYS .IO.SYS .
► The initial file, IO.SYS includes a file called SYSINIT which loads theThe initial file, IO.SYS includes a file called SYSINIT which loads the
remaining OS into the RAM.remaining OS into the RAM.
► SYSINIT loads a system file MSDOS.SYS that knows how to work withSYSINIT loads a system file MSDOS.SYS that knows how to work with
BIOS.BIOS.
► One of the first OS files that is loaded is the system configuration file,One of the first OS files that is loaded is the system configuration file,
CONFIG.SYS in case of DOS. Information in the configuration file tellsCONFIG.SYS in case of DOS. Information in the configuration file tells
loading program which OS files need to be loaded (e.g. drivers)loading program which OS files need to be loaded (e.g. drivers)
► Another special file that is loaded is one which tells what specificAnother special file that is loaded is one which tells what specific
applications or commands user wants to be performed as part ofapplications or commands user wants to be performed as part of
booting process. In DOS, it is AUTOEXEC.BAT. In Windows, it’sbooting process. In DOS, it is AUTOEXEC.BAT. In Windows, it’s
WIN.INI .WIN.INI .
13. Course Presentation
ReferencesReferences
►Operating System Principles – Silberchatz,Operating System Principles – Silberchatz,
Galvin and Gagne.Galvin and Gagne.
► http://en.wikipedia.org/wiki/Bootinghttp://en.wikipedia.org/wiki/Booting
► http://computer.howstuffworks.com/bios2.htmhttp://computer.howstuffworks.com/bios2.htm
14. Course Presentation
QuestionsQuestions
► What is the effect on boot sector and boot loader when you install twoWhat is the effect on boot sector and boot loader when you install two
OS, for e.g. Windows and Linux in two separate partitions ?OS, for e.g. Windows and Linux in two separate partitions ?
► Suppose, you install Windows first. The default boot loader installed inSuppose, you install Windows first. The default boot loader installed in
MBR is NTLDR and contains information regarding the active partitionMBR is NTLDR and contains information regarding the active partition
of Windows. When you install Linux on this system, the installationof Windows. When you install Linux on this system, the installation
prompts to overwrite a new secondary boot loader which identifies bothprompts to overwrite a new secondary boot loader which identifies both
Windows and Linux active partitions and therefore we get a choice ofWindows and Linux active partitions and therefore we get a choice of
booting the desired OS when the system is started.booting the desired OS when the system is started.
In contrast, if Linux is installed first and then Windows, theIn contrast, if Linux is installed first and then Windows, the
Windows Installer overwrites the MBR with its own boot loader whichWindows Installer overwrites the MBR with its own boot loader which
doesn’t recognize the Linux active partition. This creates a problem.doesn’t recognize the Linux active partition. This creates a problem.
The problem can be corrected by using a LiveCD or any bootable discThe problem can be corrected by using a LiveCD or any bootable disc
which can be used to reinstall a secondary boot loader which identifieswhich can be used to reinstall a secondary boot loader which identifies
both the OS and gives true choice.both the OS and gives true choice.
15. Course Presentation
QuestionsQuestions
► (1) Why is ROM slower than RAM ?(1) Why is ROM slower than RAM ?
(2) How is the boot loader copied from ROM to RAM ?(2) How is the boot loader copied from ROM to RAM ?
► (1)(1) Semi-conductor Technology used in constructing theseSemi-conductor Technology used in constructing these
two type of memories gives the answer. RAM is based ontwo type of memories gives the answer. RAM is based on
positive feedback/capacitive charge for storing thepositive feedback/capacitive charge for storing the
information while ROM contains permanent and non-information while ROM contains permanent and non-
changeable information stored in its structure.changeable information stored in its structure.
(2) There is a small routine loaded by the BIOS which does(2) There is a small routine loaded by the BIOS which does
this task. This routine could also be part of BIOS (thoughthis task. This routine could also be part of BIOS (though
not sure).not sure).
16. Course Presentation
QuestionsQuestions
► Examples of Applications that access the BIOSExamples of Applications that access the BIOS
directly.directly.
► Windows Server 2003 SP1 versions of theWindows Server 2003 SP1 versions of the
Windows Preinstallation Environment (WinPE) -Windows Preinstallation Environment (WinPE) -
http://www.microsoft.com/technet/prodtechnol/windowhttp://www.microsoft.com/technet/prodtechnol/window
► The operating system and application programsThe operating system and application programs
both directly access BIOS routines to provideboth directly access BIOS routines to provide
better compatibility for such functions as screenbetter compatibility for such functions as screen
display.display.
17. Course Presentation
QuestionsQuestions
► If I have only a single OS, is there a secondary boot loaderIf I have only a single OS, is there a secondary boot loader
present on the system ?present on the system ?
► Older machines might not have this feature. But now-a-Older machines might not have this feature. But now-a-
days, even Windows is installed with a default secondarydays, even Windows is installed with a default secondary
boot loader (NTLDR). Linux is also installed usually withboot loader (NTLDR). Linux is also installed usually with
LILO or GRUB as the default boot loader.LILO or GRUB as the default boot loader.
You might have also encountered that your systemYou might have also encountered that your system
(Windows) is not able to boot after flashing the BIOS and is(Windows) is not able to boot after flashing the BIOS and is
displaying the message “NTLDR missing”. This is becausedisplaying the message “NTLDR missing”. This is because
the primary boot loader transfer to NTLDR which mightthe primary boot loader transfer to NTLDR which might
have become corrupt or deleted by mistake.have become corrupt or deleted by mistake.
18. Course Presentation
QuestionsQuestions
► Difference between Boot Loader and BootDifference between Boot Loader and Boot
Manager ?Manager ?
► Basically, these two are different but areBasically, these two are different but are
sometimes combined into a single program.sometimes combined into a single program.
► IBM's Boot Manager, PowerQuest's BootMagicIBM's Boot Manager, PowerQuest's BootMagic
and V Communications' System Commander areand V Communications' System Commander are
some examples of boot managers.some examples of boot managers.
► Dual bootingDual booting is the act of installing multipleis the act of installing multiple
operating systemsoperating systems on aon a computercomputer, and being able, and being able
to choose which one toto choose which one to bootboot when switching onwhen switching on
the computer. The program, which makes dualthe computer. The program, which makes dual
booting possible is called abooting possible is called a boot loaderboot loader..
19. Course Presentation
InformationInformation
► Dual BootDual Boot
► In theIn the OS/2OS/2 world, the termworld, the term dual bootdual boot has a more specific meaning.has a more specific meaning.
► In aIn a dual bootdual boot installation, two (or more)installation, two (or more) operating systemsoperating systems areare
installed in ainstalled in a singlesingle partitionpartition. Selection of which operating system to. Selection of which operating system to
boot is performed by running aboot is performed by running a dual bootdual boot utility program, whichutility program, which
switches around the necessaryswitches around the necessary boot loadersboot loaders programs (by renamingprograms (by renaming
files and copyingfiles and copying boot sectorsboot sectors) to ensure that the chosen operating) to ensure that the chosen operating
system is loaded at the next boot.system is loaded at the next boot.
► In aIn a boot managerboot manager installation, by contrast, the two (or more)installation, by contrast, the two (or more)
operating systemsoperating systems are installed in their own, separate, individual,are installed in their own, separate, individual,
partitionspartitions. Rather than booting directly into an operating system, the. Rather than booting directly into an operating system, the
machine boots into a specialised,machine boots into a specialised, operating systemoperating system neutral,neutral,
boot loaderboot loader program (such as IBM's eponymousprogram (such as IBM's eponymous Boot ManagerBoot Manager))
installed on a floppy disk or in its own partition on a hard disk. Thisinstalled on a floppy disk or in its own partition on a hard disk. This
boot loader program presents a list of the available bootable partitionsboot loader program presents a list of the available bootable partitions
from which the user can choose, and then loads and invokes the bootfrom which the user can choose, and then loads and invokes the boot
loader in the boot sector of the chosen partition, to boot the chosenloader in the boot sector of the chosen partition, to boot the chosen
operating system.operating system.
20. Course Presentation
InformationInformation
► When installing an OS on a computer from scratch, here is how the partitionWhen installing an OS on a computer from scratch, here is how the partition
table is created.table is created.
► The hard disk is denoted as “hda” where hd=hard disk, and the third letterThe hard disk is denoted as “hda” where hd=hard disk, and the third letter
could mean the hard-disk on the system. For e.g. the first hard disk is “hda”,could mean the hard-disk on the system. For e.g. the first hard disk is “hda”,
the second is “hdb”.the second is “hdb”.
► When the partitioning is done, “hda0” is the place of MBR. “hda1” is the primaryWhen the partitioning is done, “hda0” is the place of MBR. “hda1” is the primary
partition. Then a secondary partition may be created which is further subdividedpartition. Then a secondary partition may be created which is further subdivided
into logical drives. Another OS could be installed on any of these logical drives.into logical drives. Another OS could be installed on any of these logical drives.
► hda0 – MBRhda0 – MBR
hda1 – Primary Partition e.g. Windows XPhda1 – Primary Partition e.g. Windows XP
hda2 – Secondary Partitionhda2 – Secondary Partition
hda3 – Logical Drive 1 (FAT32 or NTFS partition)hda3 – Logical Drive 1 (FAT32 or NTFS partition)
hda4 – Logical Drive 2 (FAT32 or NTFS partition)hda4 – Logical Drive 2 (FAT32 or NTFS partition)
hda5 – Logical Drive 3 (Swap for Linux Partition)hda5 – Logical Drive 3 (Swap for Linux Partition)
hda6 – Logical Drive 4 (Root for Linux Partition)hda6 – Logical Drive 4 (Root for Linux Partition)
The above example is a simple example. Specific cases can be different.The above example is a simple example. Specific cases can be different.
21. Course Presentation
InformationInformation
► When the kernel is being loaded, the control is inWhen the kernel is being loaded, the control is in
the privileged mode. If the user is allowed to loginthe privileged mode. If the user is allowed to login
in the same mode, any user will be “root” orin the same mode, any user will be “root” or
“administrator” (super-user). When the booting is“administrator” (super-user). When the booting is
almost complete, which is with the privileged right.almost complete, which is with the privileged right.
But this login program, after verifying yourBut this login program, after verifying your
password, gives you a shell by creating anotherpassword, gives you a shell by creating another
process which intentionally drops the super-userprocess which intentionally drops the super-user
privileges and assume the privileges of this user.privileges and assume the privileges of this user.
Login program is trusted by the kernel. If that isLogin program is trusted by the kernel. If that is
hacked or replaced, you can get a root shell fromhacked or replaced, you can get a root shell from
any login.any login.