整理1.1~1.3
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1 Introduction
01.作業系統的目標(Operating system goals):
-執行使用者的程式、解決使用者的問題
-讓電腦系統方便的被使用
-有效率的管理電腦硬體
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1.1 What Operating Systems Do
02.電腦系統可被分為四個構成要素(Computer system can be divided into four components):
-硬體
-作業系統
-應用程式
-使用者(包含人、機器或其他電腦)
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1.1.1 User View
1.1.2 System View
03.作業系統做什麼(What Operating Systems Do)
-Depends on the point of view
+User View
-Users want convenience, ease of use，Don’t care about resource utilization
-Handheld computers are resource poor, optimized for usability and
battery life
-......
+System View
-作業系統是一個資源分配者(OS is a resource allocator)
+管理所有的資源
+當需求互相衝突時，決定資源要配給何者
-作業系統是一個控制程式(OS is a control program)
+管理使用者程式的執行，避免錯誤與不合適(errors and improper)的使用電腦
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1.1.3 Defining Operating Systems
04.定義作業系統(Operating System Definition)
-In general, we have no completely adequate definition of an operating system.
+In addition,wehave no universally accepted definition of what is part of
the operating system.
+operating system is the one program running at all times on the computer
called the kernel
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1.2 Computer-System Organization
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1.2.1 Computer-System Operation
05.電腦啟動
-電腦啟動時bootstrap program會被載入到記憶體中
-bootstrap program通常放在ROM或EPROM，作為韌體(firmware)存在
-初始化系統的各個層面
+初始化CPU的暫存器(CPU registers)
+初始化裝置控制器(device controllers)
+初始化記憶體的內容(memory contents)
-載入並執行作業系統的核心(kernel)
06.中斷(interrupt) (p8)
-軟體發出中斷
+executing a special operation called a system call
-硬體發出中斷
+sending a signal to the CPU, usually by way of the system bus
-中斷向量(interruptvector)
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1.2.2 Storage Structure
07.Memory的種類
-DRAM(dynamic random-access memory)
-ROM(read-only memory)
+因為ROM不能被修改，只有static的程式，像是開機程式被存在那
-EEPROM(electrically erasable programmable read-only memory)
+EEPROM無法被頻繁的修改，通常放著不易改變的程式，以智慧型手機來說，
EEPROM存著原廠安裝的程式
08.Storage-device hierarchy
-根據速度價錢以及volatile/nonvolatile，可由高到低排成這樣的層級
+Register
+Cache
+Main memory(DRAM)
+SSD(solid-state disk)
+Magnetic disk
+Optical disk
+Magnitic tapes
-
09.volatile storage 與 nonvolatile storage
-volatile storage 在停止供電後，會失去所有儲存的資料
-nonvolatile storage 在停止供電後，不會失去儲存的資料
10.其他特殊設備
-NVRAM(nonvolatile random-access memory)
+透過DRAM+電池，擁有DRAM的速度，並能在斷電後保有資料(看電池能用多久)
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1.2.3 I/O Structure
11.device controller 與 device driver (p12)
-每個device driver都是特定用於某個device controller上的
-device controller位於硬體上，擁有自己的Buffer與Register
-device driver會去適當的讀取device controller的Register，判斷要做甚麼
(such as “read a character from the keyboard”
-作業系統針對不同的device controller擁有不同的device driver
12.DMA(direct memory access)
-device controller不透CPU，直接把自己整個Block的Buffer傳輸到Main memory的某部分，
每傳完一個Block丟出一個interupt，通知device driver操作已經完成
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1.3 Computer-System Architecture
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1.3.1 Single-Processor Systems
13.Single-Processor Systems
-僅具有一個用來處理Instruction set的主CPU
-幾乎所有的Single-Processor Systems架構仍具有其他.special-purpose processors，
不過並不會因為有這些special-purpose processors，讓架構變成Multiprocessor systems
14.special-purpose processors
-They may come in the form of device-specific processors
+disk controllers
-a disk-controller microprocessor receives a sequence of requests
fromthe main CPU and implements its own disk queue and scheduling algorithm
+keyboard controllers
+graphics controllers
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1.3.2 Multiprocessor Systems
15.Multiprocessor systems have three main advantages (p14)
-提高吞吐量(Increased throughput)
-更經濟(Economy of scale)
-增加可靠性(Increased reliability)
16.The multiple-processor systems in use today are of two types.
-不對稱多處理(Asymmetric multiprocessing)
+A boss–worker relationship. The boss processor schedules
and allocates work to the worker processors.
-對稱多處理(Symmetric multiprocessing , SMP)
+Each processor performs all tasks within the operating system
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