The document discusses key concepts related to the Windows kernel, including objects, processes, threads, virtual memory management, and helper modules. It explains that the kernel provides fundamental mechanisms and hardware support, while the executive layer manages objects like processes and threads and implements virtual memory. Processes act as containers for threads, which are the only schedulable objects, and the scheduler prioritizes and switches between threads based on their and their process' priority levels. The document also describes how each process has a private 4GB virtual address space, with the lower half for the process and upper half reserved for the kernel and drivers.
The document discusses Linux file systems. It provides an overview of Linux file system types including network file systems like NFS and SMB, and disk file systems like ext2, ext3, FAT32, and NTFS. It describes the physical structure of file systems on disk including the boot block, super block, inode list, and block list. It also summarizes the features and maximum sizes of different file system standards like ext2, ext3, ext4, ReiserFS, XFS, and JFS.
Windows 2000 architecture has a layered design with a kernel mode and user mode. The kernel mode consists of the hardware abstraction layer, kernel, and executive services which have unrestricted system access. The user mode contains subsystems and has limited resource access. The kernel schedules processes and handles interrupts, synchronization, and recovery. Executive services provide common functions like I/O management, security, and power management through components like the object manager and process manager. Environment subsystems allow running applications from other operating systems by converting their API calls.
This document discusses threads and threading models. It defines a thread as the basic unit of CPU utilization consisting of a program counter, stack, and registers. Threads allow for simultaneous execution of tasks within the same process by switching between threads rapidly. There are three main threading models: many-to-one maps many user threads to one kernel thread; one-to-one maps each user thread to its own kernel thread; many-to-many maps user threads to kernel threads in a variable manner. Popular thread libraries include POSIX pthreads and Win32 threads.
Operating Systems - "Chapter 4: Multithreaded Programming"Ra'Fat Al-Msie'deen
This chapter discusses multithreaded programming and threads. It defines a thread as the basic unit of CPU utilization that allows multiple tasks to run concurrently within a process by sharing the process's resources. Different threading models like many-to-one, one-to-one, and many-to-many are described based on how user threads map to kernel threads. Common thread libraries for POSIX, Windows, and Java are also covered. The chapter examines issues in multithreaded programming and provides examples of how threads are implemented in Windows and Linux.
The document summarizes the architecture of the Linux operating system. It discusses the main components of Linux including the kernel, process management, memory management, file systems, device drivers, network stack, and architecture-dependent code. The kernel is at the core and acts as a resource manager. It uses a monolithic design. Process and memory management are handled via data structures like task_struct and buddy allocation. Virtual memory is implemented using page tables. File systems organize files in a hierarchy with inodes. Device drivers interface with hardware. The network stack follows a layered model. Architecture code is separated by subdirectory.
It is the File system that is contained on the same partition on which the "Root directory" is located. It is the File system on which all the other file systems are mounted
The Linux booting process begins when the user turns on the computer. The BIOS loads and runs a power-on self-test before finding the bootable devices and loading the boot sector from the master boot record (MBR). The MBR then loads the boot loader, such as GRUB or LILO, which loads the Linux kernel into memory and passes control to it. The kernel initializes essential system components and starts the init process, which launches other processes according to the runlevel configuration to complete the system startup.
The document discusses kernel, modules, and drivers in Linux. It provides an introduction to the Linux kernel, explaining what it is and its main functions. It then covers compiling the Linux kernel from source, including downloading the source code, configuring options, and compiling and installing the new kernel. It also discusses working with the GRUB 2 boot loader, including making temporary and persistent changes to the boot menu.
The document discusses Linux file systems. It provides an overview of Linux file system types including network file systems like NFS and SMB, and disk file systems like ext2, ext3, FAT32, and NTFS. It describes the physical structure of file systems on disk including the boot block, super block, inode list, and block list. It also summarizes the features and maximum sizes of different file system standards like ext2, ext3, ext4, ReiserFS, XFS, and JFS.
Windows 2000 architecture has a layered design with a kernel mode and user mode. The kernel mode consists of the hardware abstraction layer, kernel, and executive services which have unrestricted system access. The user mode contains subsystems and has limited resource access. The kernel schedules processes and handles interrupts, synchronization, and recovery. Executive services provide common functions like I/O management, security, and power management through components like the object manager and process manager. Environment subsystems allow running applications from other operating systems by converting their API calls.
This document discusses threads and threading models. It defines a thread as the basic unit of CPU utilization consisting of a program counter, stack, and registers. Threads allow for simultaneous execution of tasks within the same process by switching between threads rapidly. There are three main threading models: many-to-one maps many user threads to one kernel thread; one-to-one maps each user thread to its own kernel thread; many-to-many maps user threads to kernel threads in a variable manner. Popular thread libraries include POSIX pthreads and Win32 threads.
Operating Systems - "Chapter 4: Multithreaded Programming"Ra'Fat Al-Msie'deen
This chapter discusses multithreaded programming and threads. It defines a thread as the basic unit of CPU utilization that allows multiple tasks to run concurrently within a process by sharing the process's resources. Different threading models like many-to-one, one-to-one, and many-to-many are described based on how user threads map to kernel threads. Common thread libraries for POSIX, Windows, and Java are also covered. The chapter examines issues in multithreaded programming and provides examples of how threads are implemented in Windows and Linux.
The document summarizes the architecture of the Linux operating system. It discusses the main components of Linux including the kernel, process management, memory management, file systems, device drivers, network stack, and architecture-dependent code. The kernel is at the core and acts as a resource manager. It uses a monolithic design. Process and memory management are handled via data structures like task_struct and buddy allocation. Virtual memory is implemented using page tables. File systems organize files in a hierarchy with inodes. Device drivers interface with hardware. The network stack follows a layered model. Architecture code is separated by subdirectory.
It is the File system that is contained on the same partition on which the "Root directory" is located. It is the File system on which all the other file systems are mounted
The Linux booting process begins when the user turns on the computer. The BIOS loads and runs a power-on self-test before finding the bootable devices and loading the boot sector from the master boot record (MBR). The MBR then loads the boot loader, such as GRUB or LILO, which loads the Linux kernel into memory and passes control to it. The kernel initializes essential system components and starts the init process, which launches other processes according to the runlevel configuration to complete the system startup.
The document discusses kernel, modules, and drivers in Linux. It provides an introduction to the Linux kernel, explaining what it is and its main functions. It then covers compiling the Linux kernel from source, including downloading the source code, configuring options, and compiling and installing the new kernel. It also discusses working with the GRUB 2 boot loader, including making temporary and persistent changes to the boot menu.
The document discusses memory management techniques in UNIX, including swapping, demand paging, and how they are implemented in Intel Pentium hardware. Swapping involves copying processes from memory to disk swap space to free up memory. Demand paging only loads pages into memory when accessed. The Pentium supports segmentation and paging, where logical addresses are translated to linear then physical addresses using segment descriptors, page directories and tables.
The Linux directory structure is organized with / as the root directory. Key directories include /bin and /sbin for essential system binaries, /boot for boot files, /dev for device files, /etc for configuration files, /home for user home directories, /lib for shared libraries, /media and /mnt for mounting removable media, /opt for optional application software, /proc for process information, /root for the root user's home, /tmp for temporary files, /usr for secondary hierarchy data and binaries, and /var for variable data.
The kernel is the central part of an operating system that manages input/output requests and translates them into instructions for the CPU and other components. It is responsible for memory management, allocating processes to the CPU, and handling input/output from devices. The basic structure of a kernel includes facilities for the CPU, computer memory, and input/output devices. Kernels can take different forms such as monolithic, micro, hybrid, nano, or exokernel depending on their modularity and how they expose hardware resources to other parts of the system.
This document discusses making Linux capable of hard real-time performance. It begins by defining hard and soft real-time systems and explaining that real-time does not necessarily mean fast but rather determinism. It then covers general concepts around real-time performance in Linux like preemption, interrupts, context switching, and scheduling. Specific features in Linux like RT-Preempt, priority inheritance, and threaded interrupts that improve real-time capabilities are also summarized.
Talk from Embedded Linux Conference, http://elcabs2015.sched.org/event/551ba3cdefe2d37c478810ef47d4ca4c?iframe=no&w=i:0;&sidebar=yes&bg=no#.VRUCknSQQQs
The document provides an overview of the Linux kernel architecture. It discusses that the kernel includes modules/subsystems that provide operating system functions and forms the core of the OS. It describes the kernel's user space and kernel space, with user processes running in user space and kernel processes running in kernel space. System calls are used to pass arguments between the spaces. The document also summarizes several key kernel functions, including the file system, process management, device drivers, memory management, and networking.
The document discusses Linux file systems. It begins with an overview of file system architecture, including inodes, dentries, superblocks, and how data is never erased but overwritten. It then covers various local file systems like Ext2, Ext3, Ext4, ReiserFS, and XFS. Next it discusses log-structured and pseudo file systems. It also covers network file systems like NFS and CIFS. Finally it summarizes cluster, distributed, and Hadoop file systems. The document provides a technical overview of Linux file system types, structures, features and capabilities.
Threads allow a process to divide work into multiple simultaneous tasks. On a single processor system, multithreading uses fast context switching to give the appearance of simultaneity, while on multi-processor systems the threads can truly run simultaneously. There are benefits to multithreading like improved responsiveness and resource sharing.
The document discusses the Linux kernel and its structure. The Linux kernel acts as the interface between hardware and software, contains device drivers for peripherals, handles resource allocation and tracking application access to files. It is also responsible for security and access controls for users. The kernel version numbers use even numbers to indicate stable releases.
This document discusses threads and multithreading in operating systems. A thread is a flow of execution through a process with its own program counter, registers, and stack. Multithreading allows multiple threads within a process to run concurrently on multiple processors. There are three relationship models between user threads and kernel threads: many-to-many, many-to-one, and one-to-one. User threads are managed in userspace while kernel threads are managed by the operating system kernel. Both have advantages and disadvantages related to performance, concurrency, and complexity.
The document discusses Windows XP's scheduling algorithm. It uses a priority-based, preemptive approach with 32 priority levels divided into variable and real-time classes. The scheduler ensures the highest priority thread runs by maintaining queues for each priority level and traversing from highest to lowest. Threads start at the process' base priority and may have their priority lowered after time quantums expire to limit CPU consumption of compute-intensive threads.
The document summarizes Linux synchronization mechanisms including semaphores and mutexes. It discusses:
1. Semaphores can be used to solve producer-consumer problems and are implemented using a count and wait list.
2. Mutexes enforce serialization on shared memory and have fast, mid, and slow paths for lock and unlock. The mid path uses optimistic spinning and OSQs.
3. Only the lock owner can unlock a mutex, and mutexes transition to the slow path if the owner is preempted, a spinner is preempted, or the owner sleeps.
In this presentation, I am explaining about Threads, types of threads, its advantages and disadvantages, difference between Process and Threads, multithreading and its type.
"Like the ppt if you liked the ppt"
LinkedIn - https://in.linkedin.com/in/prakharmaurya
This document provides an introduction to shell scripting using the bash shell. It covers key concepts such as shell variables, command substitution, quoting, aliases, and initializing files. The shell acts as both a command-line interface and programming language. It executes commands, supports scripting through variables and control structures, and reads initialization files on startup to customize the environment. Well-formed shell scripts allow combining and sequencing commands to perform automated tasks.
The document discusses the Linux file system at three levels: hardware space, kernel space, and user space. At the hardware level, it describes how data is organized on physical storage devices like hard disks using partitions, tracks, sectors, and block allocation. In kernel space, file system drivers decode the physical layout and interface with the virtual file system (VFS) to provide a unified view to user space. Common Linux file systems like ext2, ext3, and their data structures are also outlined.
Presentation on Operating System & its ComponentsMahmuda Rahman
An operating system is a collection of software that manages computer hardware resources and provides common services for programs. It allows multiple users and programs to run concurrently, allocating resources and providing file management, security, and other core functions. Key components of an operating system include the kernel, which handles processes, memory, devices and security; the user interface; and system utilities that support functions like booting and file management. Popular operating systems include Linux, an open-source version of UNIX with components like the kernel, system utilities and libraries.
Solid-State diskA solid-state drive also known as a solid-state di.pdfsaahinmanpam
Solid-State disk
A solid-state drive also known as a solid-state disk though it contains neither a real disk nor a
drive speed to spin a disk is a solid-state storage machine. SSD is a pc storage space device that
uses solid state recollection to store in sequence. SSD uses non volatile NAND flash memory
which enable it to train data after the control is detached SSD is normally used to pass on to solid
state storage space that is filled in a hard disk form factor
Advantages are High read bandwidth, higher IOPS, higher mechanical reliability
Disadvantages are Limited capacity, lower streaming write bandwidth
Shell script
A shell script is a computer program planned to run via the UNIX shell, a command line analyst.
The different dialects of shell script are measured to be scripting languages. Usual operation
perform by shell script include file management, program execution, and printing text. Mainly
scripts are compilation of commands to be store in a file. The shell can read file and act the
commands as if they be type at the keyboard. order of n number of commands to you store text
file and execute the file in its place of inflowing commands
System calls
We can speak to For Performing some process users have to Request for a examine since the
System. For Making any Request a user will organize a individual call which is also known as
the System Call
Types of system cell
Process manage
File organization
Device managing
Information protection
Communication
Fork () and excel ()
Fork (): When you come up to to symbolic \"fork in the road\" you normally have two options to
arrest, and your option affects your upcoming. Computer programs arrive at this fork in the way
when they knock the fork () system call. The operating system will make a new method that is
right the same as the close relative process. The comeback value since the system call is the only
mode the process can verify if it was the offered process or a latest one. The comeback value to
the process will be the procedure ID (PID) of the infant, even as the child will get a comeback
value of 0.
Excel (): fork provide a approach for an existing procedure to create a new one, but what about
the case where the new procedure is not part of the same program as main process when a client
starts a command it wants to run in a new procedure, but it is distinct to the shell. This is
anywhere the exec system call comes into play. Exec will replace the satisfying of the now
association process with the in order from a program binary
System programs:
In computer an operating system is a program that acts as a mediator among the client of a
computer and computer hardware. In another method a current system is the set of system
programs. System programs provide a fitting surroundings for program expansion and
implementation con be divided into
File management
Status information
File change
Programming language maintain
Program load
Communication
Application programs
Microkernels
A small modular f.
The document provides an overview of the key components of the Linux operating system, including:
1) The Linux kernel, which acts as a resource manager for processes, memory, and hardware devices.
2) Process and memory management systems that control how processes are allocated and memory is allocated and freed.
3) The file system which organizes how files are stored and accessed.
4) Device drivers that allow the operating system to interface with hardware.
5) The network stack which handles network protocols and connections.
6) Architecture-dependent code that provides hardware-specific implementations of core functions.
The document discusses memory management techniques in UNIX, including swapping, demand paging, and how they are implemented in Intel Pentium hardware. Swapping involves copying processes from memory to disk swap space to free up memory. Demand paging only loads pages into memory when accessed. The Pentium supports segmentation and paging, where logical addresses are translated to linear then physical addresses using segment descriptors, page directories and tables.
The Linux directory structure is organized with / as the root directory. Key directories include /bin and /sbin for essential system binaries, /boot for boot files, /dev for device files, /etc for configuration files, /home for user home directories, /lib for shared libraries, /media and /mnt for mounting removable media, /opt for optional application software, /proc for process information, /root for the root user's home, /tmp for temporary files, /usr for secondary hierarchy data and binaries, and /var for variable data.
The kernel is the central part of an operating system that manages input/output requests and translates them into instructions for the CPU and other components. It is responsible for memory management, allocating processes to the CPU, and handling input/output from devices. The basic structure of a kernel includes facilities for the CPU, computer memory, and input/output devices. Kernels can take different forms such as monolithic, micro, hybrid, nano, or exokernel depending on their modularity and how they expose hardware resources to other parts of the system.
This document discusses making Linux capable of hard real-time performance. It begins by defining hard and soft real-time systems and explaining that real-time does not necessarily mean fast but rather determinism. It then covers general concepts around real-time performance in Linux like preemption, interrupts, context switching, and scheduling. Specific features in Linux like RT-Preempt, priority inheritance, and threaded interrupts that improve real-time capabilities are also summarized.
Talk from Embedded Linux Conference, http://elcabs2015.sched.org/event/551ba3cdefe2d37c478810ef47d4ca4c?iframe=no&w=i:0;&sidebar=yes&bg=no#.VRUCknSQQQs
The document provides an overview of the Linux kernel architecture. It discusses that the kernel includes modules/subsystems that provide operating system functions and forms the core of the OS. It describes the kernel's user space and kernel space, with user processes running in user space and kernel processes running in kernel space. System calls are used to pass arguments between the spaces. The document also summarizes several key kernel functions, including the file system, process management, device drivers, memory management, and networking.
The document discusses Linux file systems. It begins with an overview of file system architecture, including inodes, dentries, superblocks, and how data is never erased but overwritten. It then covers various local file systems like Ext2, Ext3, Ext4, ReiserFS, and XFS. Next it discusses log-structured and pseudo file systems. It also covers network file systems like NFS and CIFS. Finally it summarizes cluster, distributed, and Hadoop file systems. The document provides a technical overview of Linux file system types, structures, features and capabilities.
Threads allow a process to divide work into multiple simultaneous tasks. On a single processor system, multithreading uses fast context switching to give the appearance of simultaneity, while on multi-processor systems the threads can truly run simultaneously. There are benefits to multithreading like improved responsiveness and resource sharing.
The document discusses the Linux kernel and its structure. The Linux kernel acts as the interface between hardware and software, contains device drivers for peripherals, handles resource allocation and tracking application access to files. It is also responsible for security and access controls for users. The kernel version numbers use even numbers to indicate stable releases.
This document discusses threads and multithreading in operating systems. A thread is a flow of execution through a process with its own program counter, registers, and stack. Multithreading allows multiple threads within a process to run concurrently on multiple processors. There are three relationship models between user threads and kernel threads: many-to-many, many-to-one, and one-to-one. User threads are managed in userspace while kernel threads are managed by the operating system kernel. Both have advantages and disadvantages related to performance, concurrency, and complexity.
The document discusses Windows XP's scheduling algorithm. It uses a priority-based, preemptive approach with 32 priority levels divided into variable and real-time classes. The scheduler ensures the highest priority thread runs by maintaining queues for each priority level and traversing from highest to lowest. Threads start at the process' base priority and may have their priority lowered after time quantums expire to limit CPU consumption of compute-intensive threads.
The document summarizes Linux synchronization mechanisms including semaphores and mutexes. It discusses:
1. Semaphores can be used to solve producer-consumer problems and are implemented using a count and wait list.
2. Mutexes enforce serialization on shared memory and have fast, mid, and slow paths for lock and unlock. The mid path uses optimistic spinning and OSQs.
3. Only the lock owner can unlock a mutex, and mutexes transition to the slow path if the owner is preempted, a spinner is preempted, or the owner sleeps.
In this presentation, I am explaining about Threads, types of threads, its advantages and disadvantages, difference between Process and Threads, multithreading and its type.
"Like the ppt if you liked the ppt"
LinkedIn - https://in.linkedin.com/in/prakharmaurya
This document provides an introduction to shell scripting using the bash shell. It covers key concepts such as shell variables, command substitution, quoting, aliases, and initializing files. The shell acts as both a command-line interface and programming language. It executes commands, supports scripting through variables and control structures, and reads initialization files on startup to customize the environment. Well-formed shell scripts allow combining and sequencing commands to perform automated tasks.
The document discusses the Linux file system at three levels: hardware space, kernel space, and user space. At the hardware level, it describes how data is organized on physical storage devices like hard disks using partitions, tracks, sectors, and block allocation. In kernel space, file system drivers decode the physical layout and interface with the virtual file system (VFS) to provide a unified view to user space. Common Linux file systems like ext2, ext3, and their data structures are also outlined.
Presentation on Operating System & its ComponentsMahmuda Rahman
An operating system is a collection of software that manages computer hardware resources and provides common services for programs. It allows multiple users and programs to run concurrently, allocating resources and providing file management, security, and other core functions. Key components of an operating system include the kernel, which handles processes, memory, devices and security; the user interface; and system utilities that support functions like booting and file management. Popular operating systems include Linux, an open-source version of UNIX with components like the kernel, system utilities and libraries.
Solid-State diskA solid-state drive also known as a solid-state di.pdfsaahinmanpam
Solid-State disk
A solid-state drive also known as a solid-state disk though it contains neither a real disk nor a
drive speed to spin a disk is a solid-state storage machine. SSD is a pc storage space device that
uses solid state recollection to store in sequence. SSD uses non volatile NAND flash memory
which enable it to train data after the control is detached SSD is normally used to pass on to solid
state storage space that is filled in a hard disk form factor
Advantages are High read bandwidth, higher IOPS, higher mechanical reliability
Disadvantages are Limited capacity, lower streaming write bandwidth
Shell script
A shell script is a computer program planned to run via the UNIX shell, a command line analyst.
The different dialects of shell script are measured to be scripting languages. Usual operation
perform by shell script include file management, program execution, and printing text. Mainly
scripts are compilation of commands to be store in a file. The shell can read file and act the
commands as if they be type at the keyboard. order of n number of commands to you store text
file and execute the file in its place of inflowing commands
System calls
We can speak to For Performing some process users have to Request for a examine since the
System. For Making any Request a user will organize a individual call which is also known as
the System Call
Types of system cell
Process manage
File organization
Device managing
Information protection
Communication
Fork () and excel ()
Fork (): When you come up to to symbolic \"fork in the road\" you normally have two options to
arrest, and your option affects your upcoming. Computer programs arrive at this fork in the way
when they knock the fork () system call. The operating system will make a new method that is
right the same as the close relative process. The comeback value since the system call is the only
mode the process can verify if it was the offered process or a latest one. The comeback value to
the process will be the procedure ID (PID) of the infant, even as the child will get a comeback
value of 0.
Excel (): fork provide a approach for an existing procedure to create a new one, but what about
the case where the new procedure is not part of the same program as main process when a client
starts a command it wants to run in a new procedure, but it is distinct to the shell. This is
anywhere the exec system call comes into play. Exec will replace the satisfying of the now
association process with the in order from a program binary
System programs:
In computer an operating system is a program that acts as a mediator among the client of a
computer and computer hardware. In another method a current system is the set of system
programs. System programs provide a fitting surroundings for program expansion and
implementation con be divided into
File management
Status information
File change
Programming language maintain
Program load
Communication
Application programs
Microkernels
A small modular f.
The document provides an overview of the key components of the Linux operating system, including:
1) The Linux kernel, which acts as a resource manager for processes, memory, and hardware devices.
2) Process and memory management systems that control how processes are allocated and memory is allocated and freed.
3) The file system which organizes how files are stored and accessed.
4) Device drivers that allow the operating system to interface with hardware.
5) The network stack which handles network protocols and connections.
6) Architecture-dependent code that provides hardware-specific implementations of core functions.
The document summarizes the architecture of the Linux operating system. It discusses that Linux is divided into the kernel space and user space. The kernel is responsible for process management, memory management, file systems, device drivers, and the network stack. It also touches on architecture-dependent code and the components of the Linux system like the kernel, user applications, and system libraries.
Windows Architecture Explained by StacksolStacksol
Now here we explained the windows architecture. The inside view of Microsoft Windows. The architecture of Windows NT, a line of operating systems produced and sold by Microsoft, is a layered design that consists of two main components, user mode and kernel mode.
Windows processes contain executable code and resources like memory. Processes start threads to perform tasks concurrently. Threads are lighter weight than processes and share process resources. The Windows kernel manages processes, threads, memory and hardware through system calls.
This document summarizes a student project on programming Linux device drivers. It discusses the key components of the Linux kernel relevant to device drivers like process management, memory management, and file systems. It also covers different types of devices, loading and unloading kernel modules, and the Linux device model. The project involved creating drivers for both wired and wireless devices and introducing a subdirectory structure for code organization.
This document provides an introduction to Linux device drivers. It discusses that device drivers provide an abstraction layer between software and hardware, hiding hardware details. It describes different types of devices like character and block devices. It covers key concepts like loadable modules, driver entry/exit points, interrupts, deferred work, and memory-mapped peripherals. The document uses serial/UART drivers and the TTY layer as examples to illustrate driver concepts.
The document discusses key concepts related to processes and threads in operating systems. It defines a process as an actively running program with its own memory space and resources. Processes contain code, data, and stack segments. Lightweight processes (LWPs) appear as virtual processors to user threads and are attached to kernel threads that the OS schedules. Threads are lightweight processes that share memory and resources within a process and run concurrently to improve performance. The document also discusses process descriptors, interrupts, system calls, and kernel threads.
This document provides an overview of the Windows Vista operating system, including:
1) It discusses the history of Windows operating systems and how Vista came to be, building on predecessors like Windows NT, 2000, and XP.
2) It describes the core components and architecture of Vista, including the kernel, processes, threads, memory management, and security features.
3) It explains the programming interfaces for Vista like Win32 and how they relate to the native NT API, allowing applications to be developed across versions of Windows.
This document discusses the key components of a file system and disk drive architecture. It covers disk structure, scheduling, management, and swap space. It describes concepts like disk formatting, boot blocks, bad blocks, and swap space location. The document also provides a high-level overview of the Windows 2000 operating system, covering its architecture, kernel, processes and threads, exceptions, and subsystems.
This document discusses the key components of a file system and disk drive operation. It covers disk structure, scheduling, management, and swap space. Disks are made up of logical blocks that are mapped to physical sectors. Scheduling algorithms like FCFS, SSTF, SCAN and C-SCAN are used to optimize disk head movement. Disk formatting partitions disks and writes file system structures. Swap space is used for virtual memory paging.
This document discusses the key components of a file system and disk drive operation. It covers disk structure, scheduling, management, and swap space. Disks are made up of logical blocks that are mapped to physical sectors. Scheduling algorithms like FCFS, SSTF, SCAN and C-SCAN are used to optimize disk head movement. Disk formatting partitions disks and writes file system structures. Swap space is used for virtual memory paging.
This document discusses the key components of a file system and disk drive operation. It covers disk structure, scheduling, management, and swap space. Disks are made up of logical blocks that are mapped to physical sectors. Scheduling algorithms like FCFS, SSTF, SCAN and C-SCAN are used to optimize disk head movement. Disk formatting partitions disks and writes file system structures. Swap space is used for virtual memory paging.
The document discusses operating systems and processes. It defines an operating system as software that controls hardware and manages resources. A process is a program in execution that has a unique ID and state. Processes go through various states like running, ready, blocked/waiting, and terminated. Threads are lightweight processes that can be scheduled independently and share resources within a process. User-level threads are managed in libraries while kernel-level threads are managed by the operating system kernel.
The document discusses operating systems and processes. It defines an operating system as software that controls hardware and manages resources. A process is a program in execution that has a unique ID and state. Processes go through various states like running, ready, blocked/waiting, and terminated. Threads are lightweight processes that can be scheduled independently and share resources within a process. User-level threads are managed in libraries while kernel-level threads are managed by the operating system kernel.
A device driver allows operating systems and programs to interact with hardware devices. This document discusses device drivers in Linux, including that drivers are loaded as kernel modules, communicate between user and kernel space, and have character, block, and network classes. It provides examples of initializing and removing a sample "memory" driver that allows reading from and writing to a character device memory buffer.
The document discusses operating system layers and components. It describes how kernels and servers work together to perform invocation-related tasks like communication, scheduling, and resource management. Kernels set protection for physical resources through memory management and address spaces. Processes have separate user and kernel address spaces to safely access resources. Threads and processes are core components managed by the operating system.
The Linux kernel acts as an interface between applications and hardware, managing system resources and providing access through system calls; it uses a monolithic design where all components run in the kernel thread for high performance but can be difficult to maintain, though Linux allows dynamic loading of modules. Device drivers interface hardware like keyboards, hard disks, and network devices with the operating system, and are implemented as loadable kernel modules that are compiled using special makefiles and registered with the kernel through system calls.
A Unix shell reads commands from the command line and executes actions. A session is a collection of one or more process groups created by a process calling setsid. Signals provide a way to handle asynchronous events like interrupts. UNIX originated as a single-user system at Bell Labs in 1969 and became a popular multi-user operating system. Message queues are linked lists used for communication between related or unrelated processes. Directories contain directory entries with file names and attributes. A process executes a program, while a program resides on disk. File types include regular files, directories, character/block special files, FIFOs, sockets and symbolic links.
2. Introduction to Windows Kernel
Helper modules of Windows Kernel
Process Threads and Jobs
Virtual Memory Management in Windows
Conclusion
3. In the Windows operating system, an object is a single, run-time instance of a statically
defined object type.
An object type comprises a system-defined data type, functions that operate on instances
of the data type, and a set of object attributes.
These objects are based on lower-level objects that Windows creates and manages.
In Windows, a process is an instance of the process object type, a file is an instance of
the file object type, and so on.
4. An object attribute is a field of data in an object that partially defines the object’s
state.
Object methods, the means for manipulating objects, usually read or change the
object attributes.
For example, the open method for a process would accept a process identifier as
input and return a pointer to the object as output.
5. Windows kernel is the core part of Windows Operating System. It is monolithic kernel
and contained in (%SystemDir%System32ntoskrnl.exe).
Windows Kernel provides service routines and helper functions to access system
resources and Hardware of Computer.
For example An application might want to read certain data from the File.
There is ReadFile Application Programming Interface exported by Kernel32.dll.
When Application call that function then Windows executes this call as follows:
First , Control transferred to the ReadFile Api’s code contained in Kernel32.dll.
The code contained in Kernel32.dll now performs initial checking of its parameters.
6. For reference the definition of ReadFile api in msdn is as follows:
• BOOL WINAPI ReadFile(
• __in HANDLE hFile,
• __out LPVOID lpBuffer,
• __in DWORD nNumberOfBytesToRead, _
• _out_opt LPDWORD lpNumberOfBytesRead,
• __inout_opt LPOVERLAPPED lpOverlapped
);
If the parameter seems to be valid at That time. ReadFile api call now NtReadFile
function contained in Ntdll.dll.
Ntdll.dll is entry point to Kernel executive’s services. It now performs more accurate
validation of The parameters And then enters into Kernel mode (in ring 0 ). For Intel
processors it execute SYSENTER instruction to enter into Kernel mode.
Then Kernel dispatch this system call to appropriate service routine.
7. As you have seen in ReadFile Api the first parameter of it is “HANDLE hFile” , is
analogues to the object reference.
You can get this reference by the Api that responsible for creating Object.
Kernel defines the basic functions and Object for that and taking it as base The upper
layer executive defines more concrete object like file , registry key etc , that comprises
of one or more kernel’s primitive object.
That routine then finds appropriate device driver to Handle the request.
The device driver than call the routines in Kernel and Hardware Abstraction
Layer(HAL) to Perform the actual reading.
The data transferred to the buffer provided by the application in lpBuffer parameter.
Though Windows is not strict Object Oriented Operating system . Almost every
resource have its Wrapper object and functions that access or properly manipulate the
resources.
8.
9. There are main three helper modules that provide functionality additional than core
services. these modules and Windows Kernels are dependent on each others. HAL.DLL
The hardware abstraction layer (HAL) is a key part of making this portability possible.
The HAL is a loadable kernel-mode module (Hal.dll) that provides the low-level interface
to the hardware platform on which Windows is running. It hides hardware-dependent details
such as I/O interfaces, interrupt controllers, and multiprocessor communication mechanisms
—any functions that are both architecture-specific and machine-dependent.
So rather than access hardware directly, Windows internal components as well as user-
written device drivers maintain portability by calling the HAL routines when they need
platform dependent information.
For this reason, the HAL routines are documented in the WDK. To find out more about the
HAL and its use by device drivers, refer to the WDK. Win32k.sys
10. The kernel mode driver (Win32K.sys) contains:
The window manager, which controls window displays; manages screen output; collects
input from keyboard, mouse, and other devices; and passes user messages to
applications.
The Graphics Device Interface (GDI), which is a library of functions for graphics output
devices.
It includes functions for line, text, and figure drawing and for graphics manipulation.
Wrappers for DirectX support that is implemented in another kernel driver
(Dxgkrnl.sys).
11. Kernel Executive (Upper Layer Of Kernel) :
Kernel leaves almost all possible policy making on Executive. Executive create and
manipulate objects that comprises of one or more Kernel’s primitive objects.
The Windows executive is the upper layer of Ntoskrnl.exe. (The kernel is the lower
layer.)
The executive includes the following types of functions:
Functions that are exported and callable from user mode. These functions are called
system services and are exported via Ntdll.Dll Most of the services are accessible
through the Windows API or the APIs of another environment subsystem.
A few services, however , are not available through any documented subsystem
function. (Examples include LPCs and various query functions such as
NtQueryInformationProcess, specialized functions such as NtCreatePagingFile, and
so on.)
12. Device driver functions that are called through the use of the DeviceIoControl function.
This provides a general interface from user mode to kernel mode to call functions in
device drivers that are not associated with a read or write.
Functions that can be called only from kernel mode that are exported and are
documented in the WDK.
Functions that are exported and callable from kernel mode but are not documented in the
WDK (such as the functions called by the boot video driver, which start with Inbv).
The process and thread manager creates and terminates processes and threads. The
underlying support for processes and threads is implemented in the Windows kernel; the
executive adds additional semantics and functions to these lower-level objects.
13. The memory manager implements virtual memory, a memory management scheme that
provides a large, private address space for each process.
That can exceed available physical memory. The memory manager also provides the
underlying support for the cache manager.
14. The kernel consists of a set of functions in Ntoskrnl.exe that provide fundamental
mechanisms (such as thread scheduling and synchronization services) used by the
executive components , as well as low-level hardware architecture–dependent support
(such as interrupt and exception dispatching), that is different on each processor
architecture.
The kernel code is written primarily in C, with assembly code reserved for those tasks
that require access to specialized processor instructions and registers not easily
accessible from C.
15. Processes and Threads in Kernel are implemented as an Object.
In Windows Process is just acts as a container for Threads. That means in Windows Only
threads are schedulable Object.
Windows Kernel exposes Process creation and Thread creation facility by
ZwCreateProcess and ZwCreateThread.
16. In Windows context switching occurs When the Application in Windows transit from
User Mode to Kernel Mode and Scheduler detects that the time quantum of Thread has
been expired , or Application waits for some event to be happen.
In both the cases , Scheduler then tries to search the another Thread that is schedulable
and Start it.
17.
18. Windows scheduler supports both Thread Relative Priority levels and Process Priority.
Process Priority are Low , Below Normal, Normal , Normal , Above Normal , High ,and
Realtime .
Whereas Thread Priority levels are 0 to 31 in Windows. That are called Relative Thread
Priority Levels because How Windows scheduler interprets them depends on
corresponding Process ‘ s Priority .
Every Thread or Process has one Id associated with it . This id is unique throughout the
system . And processes and Threads in Windows shares same namespace for ids.
The api for setting Threads or processes priority is SetProcessPriority and
SetThreadPriority.
19. IN Windows Every Application that runs in User Mode has been provided 4 GB of
virtual Memory space for its Data and code.
Although , The Actual Memory space that can be used by Windows Application is the
Lower half of this address space (x00000000 through x7FFFFFFF) and the upper half is
used by Kernel or its Helper modules (x80000000 through xFFFFFFFF ).
20.
21. The mappings of the lower half change to reflect the virtual address space of the
currently executing process.
But the mappings of the upper half always consist of the operating system’s virtual
memory.
Because Every process has its own private address space . Then two application can’t
access each other’s data or code without proper sharing.
Starting From Windows vista and Windows server 2008 the user can enable or set
increaseuserva flag at boot time. Because of this the application that have special flag set
in Their Header can have 3 gb of address space. So, The application can allocate or
commit more memory than the regular application.