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Instructions that control interrupts.
Instructions that manage memory mapping and Set the time of day clock.
Instructions that actually access input/output devices by i/o commands or read/write device registers.
Instructions that allow access to memory outside of a users allocated memory area.
Instructions that let you modify system software
Instructions that let you gain priority or privilege not appropriate for your user account.
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Difference between kernel mode and user mode?
Kernel ModeIn Kernel mode, the executing code has complete and unrestricted access to the underlying hardware. It can execute any CPU instruction and reference any memory address. Kernel mode is generally reserved for the lowest-level, most trusted functions of the operating system. Crashes in kernel mode are catastrophic; they will halt the entire PC.User ModeIn User mode, the executing code has no ability to directly access hardware or reference memory. Code running in user mode must delegate to system APIs to access hardware or memory. Due to the protection afforded by this sort of isolation, crashes in user mode are always recoverable. Most of the code running on your computer will execute in user mode.
What are the two modes in which windows 2000xp operates?
user mode and kernel mode
What are the differences between minimum mode and maximum mode?
http://wiki.answers.com/Q/What_are_the_differences_between_minimum_mode_and_maximum_mode maximum mode?
Why the te10 mode is the dominant mode in rectangular waveguide?
TE10 mode is the dominant mode with a>b, since it has the lowest attenuation of all modes. Either m or n can be zero, but not both.
What two main components is used by Kernel mode?
The kernel is a program that constitutes the central core of a computer operating system. It has complete control over everything that occurs in the system.A kernel can be contrasted with a shell (such as bash, csh or ksh in Unix-like operating systems), which is the outermost part of an operating system and a program that interacts with user commands. The kernel itself does not interact directly with the user, but rather interacts with the shell and other programs as well as with the hardware devices on the system, including the processor (also called the central processing unit or CPU), memory and disk drives.The kernel is the first part of the operating system to load into memory during booting (i.e., system startup), and it remains there for the entire duration of the computer session because its services are required continuously. Thus it is important for it to be as small as possible while still providing all the essential services needed by the other parts of the operating system and by the various application programs.Because of its critical nature, the kernel code is usually loaded into a protected area of memory, which prevents it from being overwritten by other, less frequently used parts of the operating system or by application programs. The kernel performs its tasks, such as executing processes and handling interrupts, in kernel space, whereas everything a user normally does, such as writing text in a text editor or running programs in a GUI (graphical user interface), is done in user space. This separation is made in order to prevent user data and kernel data from interfering with each other and thereby diminishing performance or causing the system to become unstable (and possibly crashing).When a computer crashes, it actually means the kernel has crashed. If only a single program has crashed but the rest of the system remains in operation, then the kernel itself has not crashed. A crash is the situation in which a program, either a user application or a part of the operating system, stops performing its expected function(s) and responding to other parts of the system. The program might appear to the user to freeze. If such program is a critical to the operation of the kernel, the entire computer could stall or shut down.The kernel provides basic services for all other parts of the operating system, typically including memory management, process management, file management and I/O (input/output) management (i.e., accessing the peripheral devices). These services are requested by other parts of the operating system or by application programs through a specified set of program interfaces referred to as system calls.Process management, possibly the most obvious aspect of a kernel to the user, is the part of the kernel that ensures that each process obtains its turn to run on the processor and that the individual processes do not interfere with each other by writing to their areas of memory. A process, also referred to as a task, can be defined as an executing (i.e., running) instance of a program.The contents of a kernel vary considerably according to the operating system, but they typically include (1) a scheduler, which determines how the various processes share the kernel's processing time (including in what order), (2) a supervisor, which grants use of the computer to each process when it is scheduled, (3) an interrupt handler, which handles all requests from the various hardware devices (such as disk drives and the keyboard) that compete for the kernel's services and (4) a memory manager, which allocates the system's address spaces (i.e., locations in memory) among all users of the kernel's services.The kernel should not be confused with the BIOS (Basic Input/Output System). The BIOS is an independent program stored in a chip on the motherboard (the main circuit board of a computer) that is used during the booting process for such tasks as initializing the hardware and loading the kernel into memory. Whereas the BIOS always remains in the computer and is specific to its particular hardware, the kernel can be easily replaced or upgraded by changing or upgrading the operating system or, in the case of Linux, by adding a newer kernel or modifying an existing kernel.Most kernels have been developed for a specific operating system, and there is usually only one version available for each operating system. For example, the Microsoft Windows 2000 kernel is the only kernel for Microsoft Windows 2000 and the Microsoft Windows 98 kernel is the only kernel for Microsoft Windows 98. Linux is far more flexible in that there are numerous versions of the Linux kernel, and each of these can be modified in innumerable ways by an informed user.A few kernels have been designed with the goal of being suitable for use with any operating system. The best known of these is the Mach kernel, which was developed at Carnegie-Mellon University and is used in the Macintosh OS X operating system.It is not necessary for a computer to have a kernel in order for it to be usable, the reason being that it is not necessary for it to have an operating system. That is, it is possible to load and run programs directly on bare metal machines (i.e., computers without any operating system installed), although this is usually not very practical.In fact, the first generations of computers used bare metal operation. However, it was eventually realized that convenience and efficiency could be increased by retaining small utility programs, such as program loaders and debuggers, in memory between applications. These programs gradually evolved into operating system kernels.The term kernel is frequently used in books and discussions about Linux, whereas it is used less often when discussing some other operating systems, such as the Microsoft Windows systems. The reasons are that the kernel is highly configurable in the case of Linux and users are encouraged to learn about and modify it and to download and install updated versions. With the Microsoft Windows operating systems, in contrast, there is relatively little point in discussing kernels because they cannot be modified or replaced.Categories of KernelsKernels can be classified into four broad categories: monolithic kernels, microkernels, hybrid kernels and exokernels. Each has its own advocates and detractors.Monolithic kernels, which have traditionally been used by Unix-like operating systems, contain all the operating system core functions and the device drivers (small programs that allow the operating system to interact with hardware devices, such as disk drives, video cards and printers). Modern monolithic kernels, such as those of Linux and FreeBSD, both of which fall into the category of Unix-like operating systems, feature the ability to load modules at runtime, thereby allowing easy extension of the kernel's capabilities as required, while helping to minimize the amount of code running in kernel space.A microkernel usually provides only minimal services, such as defining memory address spaces, interprocess communication (IPC) and process management. All other functions, such as hardware management, are implemented as processes running independently of the kernel. Examples of microkernel operating systems are AIX, BeOS, Hurd, Mach, Mac OS X, MINIX and QNX.Hybrid kernels are similar to microkernels, except that they include additional code in kernel space so that such code can run more swiftly than it would were it in user space. These kernels represent a compromise that was implemented by some developers before it was demonstrated that pure microkernels can provide high performance. Hybrid kernels should not be confused with monolithic kernels that can load modules after booting (such as Linux).Most modern operating systems use hybrid kernels, including Microsoft Windows NT, 2000 and XP. DragonFly BSD, a recent fork (i.e., variant) of FreeBSD, is the first non-Mach based BSD operating system to employ a hybrid kernel architecture.Exokernels are a still experimental approach to operating system design. They differ from the other types of kernels in that their functionality is limited to the protection and multiplexing of the raw hardware, and they provide no hardware abstractions on top of which applications can be constructed. This separation of hardware protection from hardware management enables application developers to determine how to make the most efficient use of the available hardware for each specific program.Exokernels in themselves they are extremely small. However, they are accompanied by library operating systems, which provide application developers with the conventional functionalities of a complete operating system. A major advantage of exokernel-based systems is that they can incorporate multiple library operating systems, each exporting a different API (application programming interface), such as one for Linux and one for Microsoft Windows, thus making it possible to simultaneously run both Linux and Windows applications.What is kernel?August 14, 2006 at 8:55 pm · Filed under Web Hosting, Windows Web HostingThe central module of an operating system. It is the part of the operating system that loads first, and it remains in main memory. Because it stays in memory, it is important for the kernel to be as small as possible while still providing all the essential services required by other parts of the operating system and applications. Typically, the kernel is responsible for memory management, process and task management, and disk management.When a computer crashes, it actually means the kernel has crashed. If only a single program has crashed but the rest of the system remains in operation, then the kernel itself has not crashed.. A crash is the situation in which a program, either a user application or a part of the operating system, stops performing its expected function(s) and responding to other parts of the system. The program might appear to the user to freeze. If such program is a critical to the operation of the kernel, the entire computer could shut down.Categories of KernelsKernels can be classified into four broad categories: monolithic kernels, microkernels, hybrid kernels and exokernels.
Does the security subsystem operate in kernel mode?
no, it wont operatesin kernel mode, it operates on usermode.
What is the distinction between kernel mode and user mode in relation as a security system?
Code running in kernel mode has unlimited access to hardware and CPU. Code in user mode can't address memory that kernel mode does not allow it to.
What mode does kernel operate in?
Machine Mode
What are some other terms for kernel mode ms for kernel mode?
Kernel mode is often referred to as "supervisor mode" or "privileged mode." These terms highlight the level of access and control the operating system has over hardware and system resources when executing code in this mode. Additionally, "system mode" is another term used to describe the same operational context where the kernel can execute critical tasks and manage resources securely.
What is the distinction of kernel mode?
no commentment
The kernel mode layer is made up of?
The Executive Services, the Hardware Abstraction Layer (HAL), the microkernal, and kernel mode drivers
What are the two modes of the windoes architecture?
User mode and Kernel mode
Difference between kernel mode and user mode?
Kernel ModeIn Kernel mode, the executing code has complete and unrestricted access to the underlying hardware. It can execute any CPU instruction and reference any memory address. Kernel mode is generally reserved for the lowest-level, most trusted functions of the operating system. Crashes in kernel mode are catastrophic; they will halt the entire PC.User ModeIn User mode, the executing code has no ability to directly access hardware or reference memory. Code running in user mode must delegate to system APIs to access hardware or memory. Due to the protection afforded by this sort of isolation, crashes in user mode are always recoverable. Most of the code running on your computer will execute in user mode.
What does the Windows kernel operate in?
hardware mode
What are the two modes in which windows 2000xp operates?
user mode and kernel mode
How does the distinction between monitor mode and user mode function as form of protection system?
The distinction between kernel mode and user mode provides a rudimentary form of protection in the following manner: Certain instructions could be executed only when the CPU is in kernel mode. Similarly, hardware devices could be accessed only when the program is executing in kernel mode. Control over when interrupts could be enabled or disabled is also possible only when the CPU is in kernel mode. Consequently, the CPU has very limited capability when executing in user mode, thereby enforcing protection of critical resources.
What mode is the operating system mode in which programs have extensive access to system information and hardware?
kernel mode
