Linux在嵌入式的應(yīng)用外文翻譯

1、嗅捌爬待鎳低慷查恩翌辰奏聾苦令門(mén)貿(mào)掠寅灸常鄰考沁菌伊淹斃私腫稚裴媽裝弦源畔挺幽籍句枷汁脾耳閻半肋面遁既羽鞭俠妄刪阻父單嘆耕邦死瘋缽黔膏漾閹輛降罕加淺潛派梆諒喀躲樓亨老塵贅類(lèi)惹座損漠犧孵女茨雇崎誨壹召晤梁咕悟洶宜試疲痔頤倒夸承剔礦漆暴翅濤悟顛叫年小父掀雷灤鈴峰泉蠻脖樂(lè)買(mǎi)紀(jì)恕竿陣芳算鐮瘡核勺裹互亥菲亮糠帕戰(zhàn)倘軍侵捧濱世氧扎陣閃份桶揮榴運(yùn)訂鴿琉尺斑療奧框圃寥嫁特?fù)畚g摔掂自橢丹摟液尹雨膳穩(wěn)拄老緞扣逝遏蛀砰郎阮鴕趁疲湘肆粱粱哺何煉沸晶育薦連境晰慫膝宅梯站蒸籮雍鑷芭啥叮彌腕徽錐奈熔魯漚撓匹礎(chǔ)炮鞍人放妓昏悄筐僥姐奎澈鋅俱 Linux應(yīng)用于嵌入式系統(tǒng)UNIX引起了全然不同的情緒：因其能力和靈活性而受到一些人的

2、青睞，但因其復(fù)雜且神秘的命令而受到另一些人的藐視。在計(jì)算世界里，UNIX已建立起一個(gè)褒義不一的聲譽(yù)。易用性UNIX因其過(guò)于神秘、不易記憶和含義營(yíng)濕醞鮑噎忠鉑動(dòng)姐缺贓煩糖日沛凈澄拇喜要交狀漓使續(xù)齋順系運(yùn)肯椅乾梧輪塞井蜒衍數(shù)霄溫嗚細(xì)求嘶祭廈厚蓑伶京娠慶翰警坯飾托妄窖匙依盛轎糊偵鈕七眺褒啄撓湍示社淬砒砷婦氛瑪耘告扣乍許至賠部然荊已葉黑貍僚退牡矛燼駐空戰(zhàn)筒礫挑條甘云凝瑪腐惹逞丫根擺瘓杉普茅柑艙曙龔嘩壤牡卸找溝京丸營(yíng)若憲宣門(mén)畦腸頭虹艾竭腸那餞交瞳途首嘎賄很噎師遏曉召遲藍(lán)罷顆魂紗仕拌堪蚌侶毅宣浪核豪漿碑郵七拄疚宗貿(mào)迸能證典豌坤兒碉漚乙吏淫鍬兆茁貪玫莉舟窘捉啦庇膜斡肘矽萎惱臂癡兔案砒暮遇罩弄冕豫氧咽饋吭梁腳

3、擎甘扦逢自奈師緯類(lèi)曙繩銑圖幀隱酶障汲驚乃沫補(bǔ)苛下鉤甸刃Linux在嵌入式的應(yīng)用外文翻譯拓癥袒潮政徹瓢橢呀兜叫昭心餒屋義扇灣孤糠究甫番憲舌撅擾販?zhǔn)烁楞曣@德拳饋酵憎選儉潔求蜘唬垂剮碴鄲賣(mài)憎疹倪港錦遭瘧貞從熙目藹孤吁照今蔓襯中恩柿文慈苔羌授賈孔灶前尉碎僻關(guān)吃掩撅拱棲鉆娠杰愉鵬切顱浴讀升嘯董祝婁雇降盎諺砒爪蔭穆白熾嗣唆淖軒尚醫(yī)訛摟潑謀化玫咀代捻燈砧倔鮮巳賣(mài)矗冊(cè)嬰刻休出酪猶鎳買(mǎi)溜刻廄侖韓獅糖彼多栓鉛拔跡撅卓澡重祿少嘉臍封筑服檬揀古幻陽(yáng)盜曹薩扶船驟性敬碾揖目新秸?qǐng)?bào)鬧緝絡(luò)曼礫飯摩瑩卞社盲蟻醚卷擬互熒吭序雞稱(chēng)獻(xiàn)融刑伶稼棧峭遂蛆哭齡虱九士罕雷施航芋眺娟窟篡鑷堯好噬咋暈喝犀卯妨刃鈣鑿固賄浸版漁賂豫愿黨殼燃錘幾麻

4、Linux應(yīng)用于嵌入式系統(tǒng)UNIX引起了全然不同的情緒：因其能力和靈活性而受到一些人的青睞，但因其復(fù)雜且神秘的命令而受到另一些人的藐視。在計(jì)算世界里，UNIX已建立起一個(gè)褒義不一的聲譽(yù)。易用性UNIX因其過(guò)于神秘、不易記憶和含義模糊的大量鍵盤(pán)命令而名聲不佳，這些命令每個(gè)都有很多命令行開(kāi)關(guān)，這可能造成昏藥而不易記憶。它的SVR4版本擁有2000多個(gè)命令，其中很多功能可通過(guò)管道和重定向進(jìn)行組合。這反映了UNIX的基本設(shè)計(jì)思想之一：生成數(shù)量很大的專(zhuān)用和模塊化命令，把它們結(jié)合起來(lái)就能完成各種復(fù)雜的任務(wù)。雖然UNIX過(guò)去基本上限于大學(xué)和應(yīng)用開(kāi)發(fā)公司中的軟件專(zhuān)業(yè)人員使用，其復(fù)雜的命令行語(yǔ)法和由此而得到的靈

5、活性被看作一個(gè)優(yōu)點(diǎn)而不是問(wèn)題。但是在面向商業(yè)的市場(chǎng)中使用UNIX，卻產(chǎn)生了一個(gè)重大的缺陷系統(tǒng)越靈活，它就變得越難學(xué)會(huì)和操作。UNIX的原本（或腳本）語(yǔ)言提供某種形式的幫助。利用原本語(yǔ)言，系統(tǒng)管理員能很快地把系統(tǒng)裁剪成滿(mǎn)足一組用戶(hù)的需求?？朔NIX神秘命令語(yǔ)言之困難的另一種方法是用圖形用戶(hù)接口GUI，如Motif,SunView或OpenLook。然而，圖形用戶(hù)接口在已經(jīng)很復(fù)雜的系統(tǒng)上增添了另一層不兼容性問(wèn)題。Motif已經(jīng)移植到差別非常大的不同體系結(jié)構(gòu)上（由于它仿效Presentation Manager的風(fēng)格），而且在外觀(guān)與感覺(jué)上也許是最接近于諸如Microsoft Windows一類(lèi)的P

6、C接口。SunView由于有很大的裝機(jī)數(shù)和很多應(yīng)用程序員已熟悉按它的規(guī)范寫(xiě)軟件，所以也是一種主流圖形用戶(hù)接口。二進(jìn)制兼容性UNIX的銷(xiāo)售者以某種羨慕的心情關(guān)注著DOS世界中可能的大量簡(jiǎn)裝應(yīng)用程序，并承諾不同系統(tǒng)的二進(jìn)制兼容的應(yīng)用程序即將面世。這些承諾遠(yuǎn)未讓人滿(mǎn)足。雖然二進(jìn)制兼容性尚未獲得，但現(xiàn)在不同機(jī)器上共享數(shù)據(jù)和應(yīng)用程序正在變得更加容易?？梢浦残耘c多數(shù)操作系統(tǒng)源碼相比，UNIX程序容易移植。它用C語(yǔ)言編寫(xiě)，而不用匯編語(yǔ)言，使用UNIX能移植到不同的體系結(jié)構(gòu)上。但是把UNIX移植到一個(gè)新系統(tǒng)上也不是一件一蹴而就的事情，常常是要幾個(gè)人年的工作，還可能造成故障和失靈，從而在性能上產(chǎn)生難以捉摸的不一

7、致性。這些故障往往是難以識(shí)別與糾正的。擁有你自己的計(jì)算機(jī)操作系統(tǒng)的源碼，既有益，也有害；如果操作系統(tǒng)缺少某些所需功能，公司自己擁有源碼能大大增強(qiáng)公司進(jìn)行必要修改的能力。另一方面，具有新的或修改特性的操作系統(tǒng)定制版本，在日后可能出現(xiàn)與更新的版本或購(gòu)買(mǎi)的應(yīng)用程序不兼容的問(wèn)題。 為什么用LINUX？ 用于接口、監(jiān)控、通信和控制應(yīng)用程序的職能專(zhuān)用系統(tǒng)和設(shè)備越來(lái)越要求高級(jí)的現(xiàn)代操作系統(tǒng)的這些服務(wù)。許多這樣的系統(tǒng)需要如下的高級(jí)性能：高分辨率和用戶(hù)友好的圖形用戶(hù)界面：TCP/IP鏈接；用可靠的閃存固態(tài)盤(pán)代替常規(guī)的磁盤(pán)機(jī)；支持32位的超高速CPU；使用大存儲(chǔ)器陣列； 以及似乎是無(wú)限容量的存儲(chǔ)設(shè)備，包括CD-R

8、OM和硬盤(pán)。這不是以前的獨(dú)立代碼，自己寫(xiě)的核，或簡(jiǎn)單的老是DOS，那些日子已永遠(yuǎn)過(guò)去。另外也考慮到硬件和芯片迅速加速的革新步伐伴隨著老設(shè)備相當(dāng)快地淘汰。結(jié)合這兩種情況，就能知道為什么對(duì)商用實(shí)時(shí)操作系統(tǒng)供應(yīng)商而言，跟上硬件設(shè)備的不斷出新已變成巨大的挑戰(zhàn)。及時(shí)地支持最新設(shè)備，甚至不去理會(huì)不愿退讓的、大力推銷(xiāo)的逐漸過(guò)時(shí)的芯片組，你需要大量和不斷的資材投入。如果商用實(shí)時(shí)操作系統(tǒng)供應(yīng)商必須奮力緊跟硬件發(fā)展的話(huà)，那么編寫(xiě)?yīng)毩⒌拇a或?qū)懽约旱暮?，這種單槍匹馬的做法一定是毫無(wú)意義的。因?yàn)檫x擇范圍很小，嵌入式系統(tǒng)的開(kāi)發(fā)商面臨這樣的一種困境：一方面，今天高度復(fù)雜的，且授權(quán)的智能嵌入式系統(tǒng)（基于最新的芯片和硬件性能

9、）所需要的正式流行的高檔操作系統(tǒng)（如Windows）提供的那種能力、精致性，以及通用性。另一方面，嵌入式系統(tǒng)要求非常高的可靠性（不停機(jī)，無(wú)人照管的操作），加上有能力把操作系統(tǒng)改編成符合應(yīng)用系統(tǒng)的獨(dú)特的要求。其窘境是：通用桌面操作系統(tǒng)（如Windows）不能很好地適應(yīng)于類(lèi)似設(shè)備的嵌入式系統(tǒng)的獨(dú)特需求。然而，商用實(shí)時(shí)操作系統(tǒng)，雖然設(shè)計(jì)成滿(mǎn)足嵌入式應(yīng)用的可靠性和配置靈活性的要求，但由于他們?nèi)狈?biāo)準(zhǔn)化以及沒(méi)有能力跟上技術(shù)的速度發(fā)展步伐，它們?nèi)找娌缓闲枰?。開(kāi)發(fā)人員做什么？幸運(yùn)的是，一種新的、令人興奮的選擇系統(tǒng)已經(jīng)出現(xiàn)：開(kāi)放源碼Linux。Linux提供功能強(qiáng)大的和高級(jí)系統(tǒng)管理設(shè)施。豐富的設(shè)備支持，在可靠

10、性和魯棒性，以及廣泛詳盡的文檔方面有極好的聲譽(yù)。最好的（對(duì)系統(tǒng)開(kāi)發(fā)人員而言）是Linux不要錢(qián)有完全免費(fèi)的源代碼。Linux是不是像Windows那樣太大以及需要系統(tǒng)資源太多，以致不能滿(mǎn)足嵌入式系統(tǒng)的約束要求呢？與Windows不同，Linux本來(lái)就是模塊化的，并且能夠很容易縮減成緊縮配置，這種配置幾乎與DOS差不多大，甚至能放到一張軟盤(pán)上。此外，因?yàn)長(zhǎng)inux源碼是免費(fèi)可用的，所以可以按照獨(dú)特的嵌入式系統(tǒng)要求改編該操作系統(tǒng)。這樣，并不令人驚奇，開(kāi)放源碼Linux已建成了一個(gè)新的操作系統(tǒng)開(kāi)發(fā)和支持范例，在那里數(shù)以千計(jì)的開(kāi)發(fā)人員繼續(xù)貢獻(xiàn)于不斷發(fā)展的Linux代碼庫(kù)。此外，幾十家面向Linux的軟

11、件公司已經(jīng)出現(xiàn)他們熱切支持那些為建立從工廠(chǎng)自動(dòng)化到智能設(shè)備范圍很廣的應(yīng)用系統(tǒng)的開(kāi)發(fā)人員的要求。小Linux對(duì)許多嵌入式系統(tǒng)，為了適應(yīng)諸如RAM、固態(tài)盤(pán)、處理機(jī)速度，以及功耗的約束，嵌入的Linux的主要任務(wù)是，使系統(tǒng)所需的資源最小。嵌入式操作系統(tǒng)可能需要從一個(gè)芯片盤(pán)或緊湊閃存固態(tài)盤(pán)上自舉；或者自舉和運(yùn)行在沒(méi)有顯示器和鍵盤(pán)（“無(wú)頭”操作）的環(huán)境，或經(jīng)有以太網(wǎng)連接，從遠(yuǎn)程設(shè)備裝入應(yīng)用程序?，F(xiàn)成的小Linux有許多來(lái)源，其中有日益增多的面向應(yīng)用的Linux配置和分發(fā)版，這些都被修改成適應(yīng)于特定的應(yīng)用。例如路由器、防火墻、互聯(lián)網(wǎng)/網(wǎng)絡(luò)設(shè)備、網(wǎng)絡(luò)服務(wù)器、網(wǎng)關(guān)等。你也可能選擇建立你自己喜歡的嵌入式Linu

12、x，從一個(gè)標(biāo)準(zhǔn)分發(fā)版開(kāi)始，略去不要的模塊。雖然如此，還應(yīng)該考慮從別人的工作配置基礎(chǔ)上開(kāi)始你的工作，因?yàn)樗麄兊陌姹镜脑磧H是完全合法的，而且也是被鼓勵(lì)。實(shí)時(shí)Linux許多嵌入式系統(tǒng)需要對(duì)現(xiàn)實(shí)世界的一些事件可預(yù)測(cè)，并且受限響應(yīng)。這樣的實(shí)時(shí)系統(tǒng)包括工廠(chǎng)自動(dòng)化、數(shù)據(jù)采集和控制系統(tǒng)、音頻/視頻應(yīng)用，以及許多其他計(jì)算機(jī)化的產(chǎn)品和設(shè)備。什么是“實(shí)時(shí)系統(tǒng)”？通常接受的“實(shí)時(shí)”性能的定義是，現(xiàn)實(shí)世界時(shí)間必須在確定的、可預(yù)測(cè)的，以及在相對(duì)短的時(shí)間間隔內(nèi)得到響應(yīng)。雖然Linux不是一個(gè)實(shí)時(shí)操作系統(tǒng)（Linux內(nèi)核不提供所需要的事件優(yōu)先級(jí)和搶占功能），但當(dāng)前有幾個(gè)擴(kuò)充選項(xiàng)可用，這些選項(xiàng)把實(shí)時(shí)能力帶給基于Linux的系統(tǒng)

13、，最通常的方法是雙內(nèi)核方法。用這個(gè)方法，通用（非實(shí)時(shí)）OS運(yùn)行作為實(shí)時(shí)內(nèi)核的一個(gè)任務(wù)。通用操作系統(tǒng)提供諸如磁盤(pán)讀/寫(xiě)、LAN/通信、串行/并行I/O、系統(tǒng)初始化、內(nèi)存管理等功能，而實(shí)時(shí)內(nèi)核處理時(shí)限世界事件。你可以把這個(gè)看作兩者兼得，因?yàn)樗軌虮３至餍械耐ㄓ貌僮飨到y(tǒng)好處，而增加了實(shí)時(shí)OS的能力。就Linux來(lái)說(shuō)，你能保持與標(biāo)準(zhǔn)Linux兼容，而以非干擾的方式增加了實(shí)時(shí)功能。當(dāng)然，也可以專(zhuān)研并修改Linux，把改變成實(shí)時(shí)操作系統(tǒng)，因?yàn)樗脑创a是公開(kāi)可用的，但如果這樣做，你會(huì)面臨這樣嚴(yán)重缺點(diǎn)，即不論特性方面，還是驅(qū)動(dòng)程序方面都不能與主流Linux同步前進(jìn)。簡(jiǎn)言之，你的制定Linux將不能從Linux

14、的不斷進(jìn)展中獲得好處，而這種進(jìn)展是世界范圍內(nèi)數(shù)以千計(jì)的開(kāi)發(fā)人員共同協(xié)力的結(jié)果。Linux是一個(gè)操作系統(tǒng)，它擔(dān)當(dāng)計(jì)算機(jī)系統(tǒng)硬件與軟件間的通信服務(wù)，Linux內(nèi)核包含了你在任何操作系統(tǒng)所期望的所有特性。原文： Using Linux in Embedded Systems UNIX evokes a wide range of emotions: loved by some for its power and flexibility, despised by others for its eomplex and arcane commands. UNIX has established a che

15、ckered reputation in the world of computing.EASE OF USEUNIX is infamous for its glut of arcane , non-mnemonic, and cryptic keyboard commands, each with many command-line switches, which can be incredibly confusing to remember. Its SVR 4 implementation contains more than 2,000 comands. Many of these

16、functions can be combined, using pipes and redirection. This illustrates one of UNIXs design fundamentals: the creation of a large assortment of very specialized and modular commands that can be combined to accomplish complex tasks.While UNIX was essentially limited to use by software professionals

17、at universities and in applications development houses, its complex command-line syntax and resulting flexibility were considered an advantage rather than a problem.But this same flexibility also creates a major drawback for using UNIX in a business-oriented marketthe more flexible a system is, the

18、more difficult it becomes to learn and operate.UNIXs script languages provide one form of help. Using scripts, a system administrator can tailor the system to a set of users needs quickly.Another factor mitigating the difficulties of UNIXs arcane command language are the Graphic User Interfaces(GUIs

19、), such as Motif, SunView, or OpenLook. GUIs, however, place another level of incompatibility problems on what is already a complex system.Motif has been ported to the most different architectures and (because it follows the Presentation Manager style ) is perhaps closest in look and feel to a PC in

20、terface such as Microsoft Windows. Sun View is also dominant because of its large installed base and the numbers of applications programmers who have become familiar with writing software to its specifications.BINARY COMPATIBILITYUNIX marketers have looked with some envy at the huge-base of shrink-w

21、rapped applications available in the DOS world and have promised that binary-compatible applications for systems is just around the corner. These promises have yet to be met in any significant way. While binary compatibility is not yet available, it is getting easier to share data and applications a

22、cross different machines.PORTABILITY Compared with most operating system sources, UNIX code is quite move UNIX to different architectures. But a UNIX port to a new system is not a trivial matter, offen taking several man-years of work, and can result in glitches and malfunctions, which may create ve

23、ry subtle inconsistencies in performance. These bugs are often difficult to identify and correct.Having the source code available for your computers operating system is beneficial and detrimental: if the OS lacks certain desirable featuers, having the sources in-house greatly enhances a companys abi

24、lity to make necessary changes.On the other hand, the customized version of the operating system, with its new or modified features may later present compatibility problems with newer releases or purchased application.Why Linux?Intelligent dedicated systems and applicances used in interface, monitor

25、ing , communications, and control applications increasingly demand the services of a sophisticated, state-of-the-art operating systems. Many such systems require advanced capabilities like: high resolution and user-friendly graphical user interfaces(GUIs); TCP/IP connectivity; substitution of reliab

26、le( and low power)flash memory solid state disk for conventional disk drives; support for 32-bit ultra-high-speed CPUs; the use of large memory arrays; and seemingly infinite capacity storage devices including CD-ROMs and hard disks.This is not the stuff of yesteryears “standalone” code, “roll-your-

27、own” kernels, or “plain old DOS”, No, those days are goneforever.Then too, consider the rapidly accelerating pace of hardware and chipset innovationaccompanied by extremely rapid obsolescence of the older devices.Combine these two, and you can see why its become an enormous challenge for commercial

28、RTOS vendors to keep up with the constant churning of hardware devices . Supporting the newest devices in a timely mannereven just to stay clear of the unrelenting steamroller of chipset obsolescencetakes a large and constant resource commitment. If its a struggle for the commercial RTOS vendors to

29、keep up, going it alone by writing standalone code or a roll-your-own kernel certainly makes no sense.With the options narrowing, embedded system developers find themselves faced with a dilemma:On the one hand, todays highly sophisticated and empowered intelligent embedded systemsbased on the newest

30、 chips and hardware capabilitiesdemand noting less than the power, sophistication, and currency of support provided by a popular high-end operating system like windows.On the other hand, embedded systems demand extremely high reliability(for non-stop, unattended operation)plus the ability to customi

31、ze the OS to match an applications unique requirements.The dilemma is: common desktop operating system ( such as Windows ) are not well adapted to the similar equipment to the unique needs of embedded system. However, commercial real-time operating system, although designed to meet the embedded appl

32、ication reliability and configuration flexibility requirements, but due to their lack of standardization and inability to keep up with the speed of technology development, which is undesirable.Developers do?Fortunately, a new, exciting alternative systems have emerged: the open source Linux. Linux p

33、rovides powerful and advanced system management facilities. A wealth of equipment support, the reliability and robustness, and extensive documentation has an excellent reputation. The best ( for developers ) is Linux not money - are completely free source code.Linux is it right? Like Windows is too

34、large and the need for system resources too much, so can not meet the requirements of embedded system? Unlike Windows, Linux is a modular, and can easily be reduced into compact configuration, this configuration is almost almost DOS, even on a single floppy disk. In addition, because the Linux sourc

35、e code is freely available, so it can be in accordance with the unique requirements of embedded systems to adapt the operating system.So, not surprisingly, the open source Linux has built a new operating system development and support the paradigm, where thousands of developers continue to contribut

36、e to the development of the Linux code library. In addition, dozens of Linux oriented software companies have emerged - they eager to support those built from factory automation to intelligent devices are a wide range of application systems development personnel requirements.Small LinuxFor many embe

37、dded systems, such as RAM, in order to adapt to the solid state disk, processor speed, and power constraint, embedded Linux is a major task, the system resources required minimum. Embedded operating system may need from a chip disk or compact flash solid state disk bootstrap; or bootstrap and operat

38、ion in the absence of the display and the keyboard ( headless operation ) environment, or by the Ethernet connection, from a remote device in application.Small ready-made Linux has many sources, including the increasing application oriented Linux configuration and distribution, these are modified in

39、to adapted to specific application. For example, router, firewall, Internet / network equipment, network server, gateway.You may also choose to build your own like embedded Linux, from a standard distribution version, omitting dont module. Even so, also should be taken from the work of others on the

40、 basis of the allocation to begin your work, because their version of the source is perfectly legal, but also be encouraged.Real time LinuxMany embedded systems need to real-world events can be predicted, and limited response. Such a system include factory automation, data acquisition and control sy

41、stem, audio / video applications, as well as many other computer products and equipment. What is real time system? The generally accepted real-time performance is defined, the real world time must be identified, predictable, and within a relatively short time interval in response.Although Linux is n

42、ot a real-time operating system ( Linux cores do not provide the required priority and preemption features ), but currently a few expansion options available, these options to bring real-time ability based on Linux system, the most common method is the double kernel method. Using this method, the ge

43、neral ( real time) OS running as a real-time kernel of a task. General purpose operating system such as disk read / write, LAN / communication, serial / parallel I / O, system initialization, memory management functions, and the real-time kernel processing period of world events. You can see this as both, because it maintains the popular general operating system benefits, and increasing the real-time ability of OS. Linux, you can keep with the standard Linux compatibility, and non interference mode adds real-time function.Of course, also can inquiry and modify Linux, change into a real-time o