嵌入式系统学习笔记.docx

入门难，视频教程+看书
嵌入式基础知识
嵌入式系统，以应用为中心，以计算机技术为基础，且软硬件可裁剪，的专用计算机系统。带有微处理器的专用系统（单片机系统、带OS的ARM系统）。

这些对比不是绝对的

交叉编译？
嵌入式系统特点：系统内核小、专用性强、系统精简、实时性、专用开发软件和环境。

嵌入式处理器，核心，

外围设备：
存储器：xram xflash
接口：并口，RS232串口，以太网接口
入机接口：LCD，触摸屏

嵌入式软件层：应用层，驱动层，OS层
嵌入式开发类：硬件开发（电路、驱动）、系统开发（linux、wince）、软件开发（应用程序、GUI）
嵌入式学习方法

Linux常用命令_格式
#command [-options] parameter1 parameter2......
VI
H左，L右，J下，K上
V可视，
Dw 删除单词的后半部分，D￥删除同行光标后的内容。2DD 删除两行。
U撤销，ctrl+r反撤销
P粘贴
R修改当前字符
Cw替换后插入字符
C$删除行后插入
2cc删除2行后插入
GCC编译器

Gcc -o main main.c
Gcc 输出 可执行文件名 程序
GNU makefile
制定编译规则，完成整个软件项目处理；分开存储，个别处理；
Shell命令解释器，编程环境
Win下的批处理

变量+规则
建立交叉编译环境
交叉编译：在一个平台（体系结构x86、ARM、操作系统win、linux）上生成另一个平台上的可执行代码。
体系结构 相互配合 操作系统

Gcc编译四个阶段：
①　 预处理，不生成文件【预处理器 cpp】
②　 转换为汇编语言，生成.s的文件【编译器egcs】
③　 转变为目标代码（ 机器代码）生成.o文件【编译器as】
④　 连接目标代码和库文件，生成可执行程序【链接器ld】

Linux平台工具
Arm920t-eabi、
Eabi优化浮点数运算

Windows平台工具
secureCRT（中断仿真程序，类似于超级终端）
Notepad++
ADS集成开发环境（操作类似于keil、中文路径下的工程文件不能被打开）
CodeWarrior IDE
HJTAG（ARM仿真、调试代理）
Dnw
ARM 微处理器
Arm7采用风诺依曼结构

Arm9采用哈佛结构

命名规则

MMU，虚拟内存单元
MPU，内存保护单元
ARM体系结构

ARM数据类型

ARM存储格式

ARM处理器工作模式

ARM中断

S3c2440a芯片

PLL倍频作用

写1清零
S3C2440存储器控制器

<>:表示以标准形式调用
慎用静态链接
Makefile
规则：产生结果的格式
Targets：prerequisites
Command
目标 依赖
命令
Main.o：main.c
Gcc -c main.c

伪目标（phony targets）

变量：
Hello：main.o fun.o
Gcc main.o fun.o
添加fun2.c

文件编程
Linux中文件编程：linux系统调用、c库

linux系统调用：int creat（const char *filename，mode_t mode）
常见创建模式：
可执行->1
可写 ->2
可读 ->4
File_creat.c
Int creat(const char *pathname,int flags,mode_t mode)
Mode指定文件权限
File_open.c
Int open(const char *pathname,int flags,mode_t mode)
例如fd=open(argv[1],O_CREAT|O_RDWR,0755)
注意o_creat：表示该文件不存在，系统会自动创建
库函数创建，文件参数由第三个参数决定；第三个参数可以没有
B区分二进制、文本文件

File_read.c
Int read(int fd ,const void *buf,size_t length)
File_write.c
Int write(int fd ,const void *buf,size_t length)
File_lseek.c
Int lseek(int fd ,offset_t offset,int whence)
将文件读写指针相对whence移动offset个字节
Whence可以用：SEEK_SET(相对文件开头)、SEEK_CUR

Lseek计算文件长度：lseek（fd,0,SEEK_END）
文件属性判断：
Access：int access(comst har*pathname,int mode)
//mode是要判断的访问权限（R_OK/W_OK/X_OK/F_OK(文件存在)），测试成功函数返回0，否则返回-1.

（英文版 ）
easily blame, to prevent the broken window effect. Supervise the leading cadres to play an exemplary role, take the lead in the strict implementation of the < code > and < rule >, lead to safeguard the solemnity and authority of the party discipline, ensure that the party discipline and the laws and regulations for implementation in place. Throughout the discipline in the daily supervision and management
, strengthen supervision and inspection, from the thorough investigation of violations of discipline behavior. Strengthen to key areas, key departments and key projects as well as the masses reflect the concentration of the units and departments for supervision. - strengthening supervision, discipline inspection and supervision of cadres to set an example for compliance with the < code > and < rule > is a man must be hexyl, blacksmith needs its own hardware. Discipline inspection organs as the executor of the party discipline, and supervisor of the defenders, for its supervision must be more strictly, discipline inspection and supervision of cadres to firmly establish the awareness of Party Constitution, sense of discipline and rules consciousness, politics loyalty, sense obey. Action speak Ji Ordinance to set an example of the regulations of the rule of law, strengthen supervision and accept the supervision of the firmness and consciousness, do comply with < > and < >. To firmly establish the discipline must first be disciplined, the supervisor will be subject to the supervision of "concept, and consciously safeguard and implement party compasses party, take the lead in practicing" three strict real strict, so loyal, clean, play. To be good at learning, the Constitution and the < code > as morality, politics and brought to fruition; to implement < >, do not want to, dare not, not with disciplinary ruler to supervision; to discipline a ruler, often the control inspection, and consciously in the ideological red line to draw the row Ming Good accumulation is indeed the bottom line, so that the heart has fear, said to have quit, the line has ended. Attached: indifferent to heart, calmly to the table in our life, there are many unpredictable things will happen, some good, some bad things, we cannot control is powerless to stop, but with time, you will find in life sometimes turns out to be not good, some bad things finally turned out to be a good thing, but then we muddy however did not know, this is the life teach us things. 1, life can be complex, can also be simple. Want simple life of precipitation, to have enough time to reflect, to make Become more perfect. Life is the most important thing is not to win, but the struggle; not to have conquered, but to have fought well. 2, the plain is the background of life. Live a plain life, give up on themselves is not a coward, but the wise answers; not disillusioned after the heart, such as ashes, but experience the storm after the enlightenment; not unrewarding perfunctorily, but calm attitude of life of unrestrained self-confidence. Plain living, there is no noise noisy, no earthly troubles, more did not fill in the discontent of desire, some just a calm, a calm. 3, memory of heart will not good things to erase the, life is a When no movie, pain is a beginning, the struggle is a kind of process, death is a kind of ending. Give up this giving up is the helpless, do not give up the abandoned, do not give up this giving up is ignorance, do not give up should not give up is persistent. 4, a thing figured is heaven, think impassability is hell. Since the living, to live better. Sometimes we because of too narrow-minded, too care around the chores and penny wise and pound foolish, not worth the candle. Some things to attract trouble and worry, completely depends on how we look at and deal with it. Don't always take everything back to things, and don't get into a blind alley, don't want to face, don't be narrow-minded. Poke to care, is a kind of open-minded, a free and easy. 5, I am not afraid of others behind me a knife, I afraid to look back and see stab me, is my intention to treat people; I am not afraid of the truth to tell the best friend, I'm afraid he turned to it as a joke to tell don't 6, when we are in a positive frame of mind, you will find many good things; and when we are in a negative state of mind, you will find many depressed things; life happy and worry, all is you of life attitude, optimistic, good luck; loss of sink, Eritrea company. When you are in adversity, may wish to change a point of view to think everything over to the good Think, because good mentality decided the fate of the! 7 people are tired, rest; heart tired, calm. Grow up, mature, this society read. Tired and sad, squat down, to their a hug. Because the world no one can sympathize with you, have mercy on you. You cry, tears is your own; you pain, no one can understand. Then you only tears to smile. 8, each people have youth,
Each youth are a story, the life of the world never gets easier, I want what, wish the world all know, as has been the same; now want anything, for fear that others know, or like to lose the same. 9, the heart move, everything in the world is followed by birth, Rangrang, important thing is often the most difficult to open one's mouth, because words will reduce its importance; to let strangers people care about your life in the good things, the original is not easy 10, do not blame, do not laugh at who, also don't envy who. Like a person is a kind of feeling, not like a person is true. The truth is easy to explain, I feel Is unspeakable. The best travel life is that you in a strange place found a long lost touched. 11, happy life not in the bustling in, and in the peace of mind; no matter how many grievances, how uncomfortable, and ultimately to heal themselves or their own, others may got you to comfort, but never know your heart is how wanjianchuanxin. 12, ma'am, like a movie, learn to appreciate, learn to be grateful, learn tolerance, and goodness, helping others. Instead of accusing the society, as into one; and an exception is better to give than to what 13, don't envy him A sum of, don't lose your life and the life, respectively is: the former is a we experienced cannot escape in a day finally will last minute, while the latter is our persistent, we want to cherish the memory of those people and things. 14, learn to smile, learn to strong, the world you know so many people, so many people and you are, you cannot change also can't let everyone like you, so also do not want to do. Life is too short to go crazy to love to go to waste, to chase the dream to regret. 15, when temper, a blessing to go. A wounding elegant people, the key is to control their own emotions. With the mouth is the most stupid behavior. A control negative emotions than a can take a city more powerful water flow slow, language is expensive. People spent two years of time to learn to speak, but to spend a few years time to shut up. That is a kind of ability, that is a kind of wisdom. 16, life is not perfect, sometimes, growth is not a cry, not an eyeful of tears, there is no trace of emotion, there is no gleam of hope, no desire, no action, no static, there is only one kind of downward sinking feeling, sink A murky? 6? 7? 6? 7 sink? 6? 7? 6? 7 toward the bottom of the sink. 17, in some way, do not go, you will not know the other side scenery is beautiful. To you is not good, you do not mind too much, no one has an obligation to you; you learn knowledge, is you have weapons, you can start from scratch, but not unarmed; how do you treat people, does not represent how others treat you, if cannot see through this point, only inviting worry. 18, time is like a sponge in the water, as long as you are willing to squeeze, the total water is still there. Every life, after the ups and downs The best test of live, to life, survival and continuation, do not stop the struggle in the joys and sorrows of life on the road, so that different soul to bear life beat, acceptance of suffering. 19, indifferent to heart, calmly in table, elegant and comfortable life, do not take what is so important. The pursuit will be disappointed; to be alive, you will have trouble. Life is the most afraid of what all want to care about, but also what all grasp is not firm, without scenery, separated populations, such as not to desire, all docked in the fate of the end. Why is too rigid, the natural, to go stay not to live, let go of obsession, revel is 20, if the fate of the broken Hopes of sailing, please don't despair, the coast is still, if the fate of the withered petals of the beautiful, please do not sink, the spring is still, life will always be endless trouble, please don't helpless, because they are still alive, is still a dream, the sun still, we still. Lost, keep memories; to get, must work to; but the most important is good to cherish their own. 21, life, select the complex, is to choose the pain; choose a simple, is choose to be happy. The complex world like a
Significance of pride. Hope is the ornate palace, outside people admiring the magnificent, living in the deep knowledge of living it to pay the price. Simple world as a simple log cabin outside ridiculed shabby, the heart is willing to go live to know the joy. Suffering and joy is their own choice. 22, learn how to use a single powerful heart, let the past be the past, let the future come. Life is really the end of the end of an eagle is flying wings, life is constantly pursuit. Don't miss to regret, don't wait for old just miss. Time to return, seize every moment, again painstakingly again tired also Those struggling to fly. 23, life could not Yimapingchuan, even flat pavement, inevitably there will be a few pieces of roadblocks. Some of the rocks around the past, while others have to move it out. Just move others put the stone is very easy, because the stone from the appearance we can discern; difficult to myself to move away the heart of stone head. Leave time to spend with her, often reflect my heart, so as to remove your heart of stone. 24, everything does not have to be demanding, come to, everything does not have to care about, over the past; failing to do not frown, laugh it laugh. Results Don't demand, do to; life is a simple, calm and peaceful. Always not to choose their own path and regret, life is like a train, the scenery and then the United States will retreat, the passage of time and encounter will eventually drifting further and further away, before is always himself. 25, everyone has a weakness, weakness is true humanity. That has no weakness, a shallow person. That people think there is no weakness, mostly false. Life has shortcomings, there are shortcomings is the real life. That no one regret, or childish or numbness or Self deception. It is in tolerance of weakness and so on to accept, people live happily.

Hello, everyone! I am a party member. The title of my speech is: < study and implement the party's two laws, doing practical play highway. 2015 October 18, the Central Committee of the Communist Party of China promulgated the implementation of the < the probity of the Communist Party of China self-discipline criterion > and < Chinese Communist Party discipline and punishment regulations. We Heyuan male passers-by to respond positively to the call of the Central Committee of the party, earnestly organize the study "party two regulations", truly grasp the essence and gist, and in their respective positions, to hold the bottom line of the discipline, build a strong ideological line of defense, with the courage to play, the courage to fight tough and fearless spirit, at the crucial moment well to complete the task, with practical action to test the study and implement effect Because of discipline in the * * * * * * * * * * * story. Here, let me to cast a brick to attract jade, speak about our highway. Highway line section of the road surface transformation project, last year "towards the country seized" will be seized one of the items. To complete this arduous task, as a project management office director Comrade, keep in mind from the Communist Party membership, recognize and identify the "bottom line", strict management, and strict adherence to the quality of the project. He not only set an example, honesty and self-discipline, but also requires the management of all the members of the O.K., do not eat the construction unit one meal, do not accept the construction unit a ceremony. In this way, they didn't really dare to adhere to the principle. No comrade, constantly put on reworking an emergency meeting to Comrade Zhen to speak louder, management tube too strict. Remember in Dongguan Street, 400 meters long c