computer security fundamentals

-dos disk operating system. It is worth mentioning that MS-DOS, which is the operating system running on IBM-PC and its compatible machine, later, Microsoft acquired the patent of the operating system, is equipped with the IBM-PC machine, and named Pc-dos. In 1987, the ms-dos3.3 version released by Microsoft was a very mature and reliable DOS version.Modern operating systems also have to go to many of the typical representative, such as: Windows, OS/2 and so on.I first write a blog, time is comp

^5. Procedure: Put on the operating system, as long as not delete it has been there. Execute the entrance, process: There is a life cycle, a certain time after the disappearance.6. Library: A bunch of programs, they can not execute independently, only provide the calling interface, can be executed by the program call.7. Operating system: With the operating system, any process to deal with the hardware, all have to go through the operating system. The operating system passes the lowest-level invo

blocked, waiting for a condition that will never be true. Programmers use P and V incorrectly so that two of the semaphore's forbidden areas overlap. Overlapping forbidden areas cause a set of states called deadlock zones. Deadlocks are unpredictable. This week's code hostingResources "In-depth understanding of computer system V2" Learning Guide 2016-2017-1 the teaching process of the basic design of information

more specific, but it's not quite understandable how the cache works, because there's some abstraction.This week's code hostingCode Link: https://git.oschina.net/929210354/LinuxLearning progress Bar lines of code (new /Cumulative) Blog volume ( new/cumulative) Learning time (new/cumulative) Important growth Goal 5000 rows 30 Articles 400 hours First week 0/0 1/2 10/10 Installing a Lin

20145216 Shi Yao "Information Security system Design Fundamentals" Seventh week Study summary teaching Contents summary Sixth chapter memory hierarchyA memory system is a hierarchical structure of storage devices with different capacities, costs, and access times.CPU registers, cache memory, primary storage, disk.The first section of storage technologyOne, random access memory (RAM)1.RAM classification:

| various information representation methods| Fifth week |250/850|1/5|25/80| compilation and disassembly# # References-[Learning Guide for in-depth understanding of computer system V2] ([http://www.cnblogs.com/rocedu/p/5826467.html])-[Introduction to Linux Basics (new version)] ([https://www.shiyanlou.com/courses/1#])-[Teaching of information security system design basics] ([http://www.cnblogs.com/rocedu/p/

, consolidate the previous knowledge, master the method of configuring the environment variables, overall, the experiment is relatively smooth, but in the completion of half the progress of the time, due to computer power, restart the computer led to the experimental content completely zeroed, Again practice again, delay the experimental process, but this makes us grasp more firmly, we will continue to work

20165230 2018-2019-1 "Information Security system Design Fundamentals" The second week study summary of learning Contents There are two general rules for arranging the bytes of an object: The small-end method (least significant byte at the front) and the big-endian (the most significant byte in front). The expression x>>k will shift the X arithmetic right to K (the left side complements the K-effectiv

time, metadata, by invoking the stat and FSTAT functions. #include The stat function takes a file name as input, and the ftast as input with a filename descriptor. Learning progress Bar Code lines (new/cumulative) Blog volume (new/cumulative) Learning Time (new/cumulative) important growth Goal 5000 rows 30 Articles 400 hours Seventh Week 1300/1750 11/11 140/140

20145306 "Fundamentals of Information Security system Design" 14th Week study summary textbook Learning content Summary physical and virtual addressingPhysical addressing: The main memory of a computer system is organized into an array of cells consisting of m contiguous byte sizes. Each byte has a unique physical address of Pa. The address of the first byte is 0

2017-2018-1 20155222 "Fundamentals of Information Security system Design" 10th week IPC mechanism under Linux The communication mechanism between multiple processes under Linux is called IPC (inter-process Communication), which is a way of communicating with each other across multiple processes. There are several ways of interprocess communication under Linux: Half-duplex pipes, Named pipes, messag

Control Message Protocol ICMP Routing protocol for Internet IP Multicast and Internet Management Protocol Next-generation Internet Protocol Ipv6 Knowledge points three, LAN and WAN LAN Overview LAN topology Traditional Ethernet Virtual Local Area Network High-speed Ethernet and other types of high-speed LANs Wireless LAN The development and working principle of Ethernet 10Base Networking Essentials and 4 types of 10Base Ethernet:10base-5 Ethernet, 10base-2 Et

the representation and processing of the information in the 2nd Chapter(i), three kinds of important digital representationsUnsigned number: The encoding is based on the traditional binary notation (numbers greater than or equal to zero).Complement: Encoding is the most common way to represent signed integers (numbers that are positive or negative).Floating-point number: The encoding is a two-base version of the scientific notation for real numbers.Although the representation of an integer can o

double. On machines that support IEEE floating-point format, these data types correspond to single-precision and double-precision floating-point.The newer version of the C language, including the ISO C99, contains the third floating-point data type long double. For many machines and compilers, this data type is equivalent to a double data type. However, for Intel compatible machines, GCC uses the 80-bit "extended precision" format to implement this data type, providing a much larger range and p

misses/number of references Hit Ratio = 1-No hit Hit time No hit penalty: Because of the extra time required to miss the 2. Specific impact: Cache Size: Hit ratio +, hit Time + Block Size: Spatial locality +, hit ratio +, number of cache rows-, time locality-, no hit penalty + Degree of coupling: E value big, jitter-, Price +, hit Time +, no hit penalty +, control logic + "compromise for not hit penalty low, low degree of coupling, not hit penalty high, use hig

Representation and processing of informationFirst, GCC compilationWhen using the C99 feature, the GCC-STD=C99 XXX.C Lab building environment is 64 bits, compiled to 32-bit machine code: Gcc-m32 xxx.cSecond, the textbook guideThree types of numbers:unsigned (unsigned) encoding is based on the traditional binary notation, which represents a number greater than or equal to zero.The complement (s-complement) encoding is the most common way to represent signed integers, which are numbers that can be

20145311 "Information Security system Design Fundamentals" The 14th Week study summary textbook Learning content Summary1. Physical AddressingThe main memory of a computer system is organized into an array of cells consisting of m contiguous byte sizes. Each byte has a unique physical address of Pa. The address of the first byte is 0, the next byte has an address

20165214 2018-2017-1 "Information Security system Design Fundamentals" The third week study summary of learning Contents1. In fact, the GCC command invokes a series of programs that convert the source code into executable code.2, the actual realization of the memory system is to combine multiple hardware memory and operating system software.3. ISA: Instruction set architecture, which defines the state of th

summary of the wrong quiz Wrong question 1 and reason, understand the situation Wrong question 2 and reason, understand the situation ... Other (sentiment, thinking, etc., optional)XxxXxxLearning progress Bar lines of code (new/cumulative) Blog Volume (Add/accumulate) Learning Time (new/cumulative) Important Growth Goal 5000 rows 30 Articles 400 hours First week 200/200 2/

, double Int→float will not overflow but may be roundedInt/float→double results retain exact valuesDouble→float may overflow to ±∞ and may be rounded due to small accuracyThe float/double→int rounds to 0 and can overflow.Problems encountered:1. Error in compiling the 28-page code in the bookCheck the code seems to be nothing wrong, do not know why ... at last, I commented out the line . The source code is as follows2. Exercise 2.52 do not understand, I hope the teacher can explain in classI