★ “长 OS Architecture ￥斗 ★★ o Environment subsystemprocesses Manage dient processesin theirword Impose semantics such as processmodel, security o Windows2000 shippedwith three environment subsystems: Win32, POSIX, and oS/2 XP has only Windows subsystem Win32 only one that matters DoS, Win3. 1 emulated by a Win32 progam Enhanced posX subsystemavailable(Interix)
6 OS Architecture Environment subsystem processes – Manage client processes in their world – Impose semantics such as process model, security Windows 2000 shipped with three environment subsystems: Win32, POSIX, and OS/2 – XP has only Windows subsystem – Win32 only one that matters – DOS, Win 3.1 emulated by a Win32 program – Enhanced POSIX subsystem available (Interix)
★ “长 OS Architecture ￥斗 ★★ System Service U support Environment processes applications processes subsystems Subsystem DLLs User mode Kernel mode Executive Windowing Kernel Device drivers and graphIcs Hardware abstraction layer(HAL
7 OS Architecture
斗 长 Kenel-Mode Components: Core OS ￥斗 ★★ o Core Osoontains twocomponents Executive and Kemel both contained in file ntoskmlexe ≈ Executive base operatingsystemservices memory management processand thread management, security, IO, inter-processcommunication
8 Kernel-Mode Components: Core OS Core OS contains two components: – Executive and Kernel – both contained in file Ntoskrnl.exe Executive – base operating system services, – memory management, process and thread management, – security, I/O, inter-process communication
斗 长 Kenel-Mode Components: Core OS ￥斗 ★★ o Kemel low-level operatingsystemfunctions thread scheduling intemuptandexceptiondispatdhing multiprocessorsyndhronization. o Kernel provides a set of routines basicobjects that the rest of the exective uses to implement higher-level constructs
9 Kernel-Mode Components: Core OS Kernel – low-level operating system functions, – thread scheduling, interrupt and exception dispatching, – multiprocessor synchronization. Kernel provides a set of routines & basic objects – that the rest of the executive uses to implement higher-level constructs
斗 长 Kemel-Mode Components: Drivers ￥斗 ★★ o Device drivers hardware device drivers translate user yo function calls into specific hardware device Iyo requests virtual devices-systemvolumes and network protocols Contained in files ending in Sys
10 Kernel-Mode Components: Drivers Device drivers – hardware device drivers translate user I/O function calls into specific hardware device I/O requests – virtual devices - system volumes and network protocols – Contained in files ending in .Sys