一個老鳥帶你(ni)了解(jie)嵌入(ru)式linux系統(tong)基礎
時間：2018-06-11 ;來源：未知
學(xue)習嵌(qian)入(ru)(ru)(ru)式linux，那(nei)么首先(xian)就(jiu)必(bi)須要了解嵌(qian)入(ru)(ru)(ru)式linux系(xi)(xi)統(tong)，及嵌(qian)入(ru)(ru)(ru)式linux系(xi)(xi)統(tong)的最(zui)為基(ji)礎的概(gai)念，今天就(jiu)讓(rang)我這(zhe)只老鳥帶你(ni)們去了解一(yi)下(xia)嵌(qian)入(ru)(ru)(ru)式linux系(xi)(xi)統(tong)的基(ji)礎知識及如(ru)何(he)一(yi)步(bu)一(yi)步(bu)對嵌(qian)入(ru)(ru)(ru)式linux系(xi)(xi)統(tong)熟悉(xi)。
首先學習一個知(zhi)識，就要(yao)做到層次化，有路線(xian)的(de)去學習，當然嵌入式linux也是這樣。
嵌入(ru)式Linux系統(tong)做模(mo)塊(kuai)化(hua)處理就是(shi)可(ke)劃分為Bootloader(引導程序)，Kernel(內(nei)核(he))，fs(文(wen)件系統(tong))，Shell(命令(ling)行界面)，Gui(圖形(xing)庫(ku))和(he) Embeded Sql(嵌入(ru)式數(shu)據庫(ku))等(deng)。以(yi)上就是(shi)嵌入(ru)式Linux系統(tong)的(de)7個重要模(mo)塊(kuai)，通過這些就可(ke)以(yi)開發(fa)出各(ge)種(zhong)各(ge)樣的(de)App(應(ying)用程序)。如上網用得網絡(luo)瀏覽器，播放歌曲(qu)的(de)音頻(pin)播放器，播放電影的(de)視頻(pin)播放器，各(ge)種(zhong)游戲(如連(lian)連(lian)看)等(deng)等(deng)。
嵌(qian)(qian)入(ru)(ru)式(shi)(shi)Linux系(xi)統(tong)--最開(kai)始就是要知道嵌(qian)(qian)入(ru)(ru)式(shi)(shi)linux系(xi)統(tong)如何安(an)裝PC安(an)裝Windows操作系(xi)統(tong)通常從光(guang)(guang)驅(qu)開(kai)始，按(an)Fn鍵進入(ru)(ru)安(an)裝模式(shi)(shi)，來讀(du)(du)取光(guang)(guang)盤并啟動安(an)裝過程。嵌(qian)(qian)入(ru)(ru)式(shi)(shi)Linux和(he)此(ci)類似，Bootoader啟動過程中(zhong)按(an)任意鍵(U-boot)進入(ru)(ru)安(an)裝模式(shi)(shi)，只不(bu)過安(an)裝不(bu)是從光(guang)(guang)驅(qu)讀(du)(du)取系(xi)統(tong)，而是從串口(UART)或者網(wang)口讀(du)(du)取系(xi)統(tong)。另外有個(ge)不(bu)同PC安(an)裝中(zhong)文件系(xi)統(tong)包含在系(xi)統(tong)之(zhi)中(zhong)，嵌(qian)(qian)入(ru)(ru)式(shi)(shi)Linux系(xi)統(tong)操作系(xi)統(tong)和(he)文件系(xi)統(tong)是分開(kai)的需要單獨安(an)裝。
嵌入(ru)式Linux系(xi)統(tong)(tong)(tong)--文(wen)件(jian)(jian)(jian)系(xi)統(tong)(tong)(tong)，即(ji)fs，是(shi)Linux系(xi)統(tong)(tong)(tong)的重(zhong)要(yao)部分(fen)，文(wen)件(jian)(jian)(jian)系(xi)統(tong)(tong)(tong)主要(yao)實(shi)現(xian)的是(shi)文(wen)件(jian)(jian)(jian)夾(jia)和(he)文(wen)件(jian)(jian)(jian)的操作(zuo)(如創建、刪除、打開、關閉、讀(du)寫等(deng))，這和(he)Windows操作(zuo)系(xi)統(tong)(tong)(tong)的文(wen)件(jian)(jian)(jian)系(xi)統(tong)(tong)(tong)比較相(xiang)似。嵌入(ru)式Linux系(xi)統(tong)(tong)(tong)下(xia)文(wen)件(jian)(jian)(jian)系(xi)統(tong)(tong)(tong)模塊(kuai)通常(chang)需(xu)要(yao)Kernel提(ti)供支持的，并包(bao)(bao)(bao)含Shell命令包(bao)(bao)(bao)，就是(shi)說嵌入(ru)式Linux文(wen)件(jian)(jian)(jian)系(xi)統(tong)(tong)(tong)不(bu)光提(ti)供對(dui)文(wen)件(jian)(jian)(jian)操作(zuo)的支持，還提(ti)供對(dui)Shell包(bao)(bao)(bao)的支持，你也(ye)許有疑問(wen)什么是(shi)Shell，請(qing)向下(xia)看(kan)。
嵌入(ru)(ru)式Linux系(xi)(xi)(xi)統--命(ming)令行，即Shell是(shi)操作(zuo)系(xi)(xi)(xi)統的(de)(de)(de)重要(yao)部分，當然也包括(kuo)嵌入(ru)(ru)式Linux系(xi)(xi)(xi)統。在(zai)Windows操作(zuo)系(xi)(xi)(xi)統下，打(da)開“開始”點進“運行”輸入(ru)(ru)“cmd”按“Enter”鍵(jian)，你就(jiu)進入(ru)(ru)了一(yi)個(ge)(ge)(ge)比較“土”的(de)(de)(de)窗口(kou)界面，這個(ge)(ge)(ge)界面就(jiu)是(shi)一(yi)個(ge)(ge)(ge) Shell，輸入(ru)(ru)“ipconfig”你就(jiu)可(ke)(ke)以看到本PC 的(de)(de)(de)IP信息。嵌入(ru)(ru)式Linux系(xi)(xi)(xi)統也有一(yi)個(ge)(ge)(ge)類(lei)似(si)的(de)(de)(de)Shell，不過不是(shi)映射到本機(如ARM硬件板)，而是(shi)映射到PC機的(de)(de)(de)串口(kou)終(zhong)端上(這里(li)概念(nian)比較多，推薦記住“映射”“ARM板”、“PC機”、“串口(kou)終(zhong)端”這幾(ji)個(ge)(ge)(ge)關鍵(jian)詞)，就(jiu)是(shi)說通過PC機的(de)(de)(de)串口(kou)終(zhong)端可(ke)(ke)以操作(zuo)嵌入(ru)(ru)式Linux的(de)(de)(de)Shell，如輸入(ru)(ru)“ifconfig”就(jiu)可(ke)(ke)以查看ARM硬件板IP信息，這個(ge)(ge)(ge)和(he)上面的(de)(de)(de)“ipconfig”作(zuo)用相同。
嵌入(ru)(ru)式(shi)Linux系(xi)(xi)統(tong)(tong)--內(nei)核，即Kernel，是Linux系(xi)(xi)統(tong)(tong)的(de)(de)(de)核心(xin)，Kernel包(bao)含了驅動程(cheng)(cheng)序，網絡(luo)協議，內(nei)存管(guan)理，文件系(xi)(xi)統(tong)(tong)，進(jin)(jin)程(cheng)(cheng)管(guan)理等模(mo)塊，這(zhe)(zhe)些概(gai)念(nian)比較抽(chou)象，在Windows操作(zuo)系(xi)(xi)統(tong)(tong)做(zuo)程(cheng)(cheng)序開(kai)發會遇(yu)到(dao)類似(si)的(de)(de)(de)模(mo)塊劃分，如(ru)果只是Windows操作(zuo)系(xi)(xi)統(tong)(tong)的(de)(de)(de)應用(yong)(yong)(yong)(yong)者是很少需要有這(zhe)(zhe)些概(gai)念(nian)的(de)(de)(de)，不過(guo)你的(de)(de)(de)使用(yong)(yong)(yong)(yong)之中(zhong)(zhong)是用(yong)(yong)(yong)(yong)到(dao)了這(zhe)(zhe)些東(dong)西。如(ru)外擴的(de)(de)(de)設備需要安裝額外的(de)(de)(de)驅動，你就用(yong)(yong)(yong)(yong)到(dao)驅動程(cheng)(cheng)序這(zhe)(zhe)種東(dong)西了;打開(kai)office時你就用(yong)(yong)(yong)(yong)到(dao)了文件系(xi)(xi)統(tong)(tong)了;上網時用(yong)(yong)(yong)(yong)到(dao)了網絡(luo)協議;同(tong)時打開(kai)千千靜聽和(he)計算器你就用(yong)(yong)(yong)(yong)到(dao)了進(jin)(jin)程(cheng)(cheng)管(guan)理。原來嵌入(ru)(ru)式(shi)Linux系(xi)(xi)統(tong)(tong)的(de)(de)(de)這(zhe)(zhe)些概(gai)念(nian)早就存在Windows操作(zuo)系(xi)(xi)統(tong)(tong)之中(zhong)(zhong)，就像遇(yu)到(dao)一個似(si)曾(ceng)相識的(de)(de)(de)人，想問一句“我們好像那里見過(guo)”。
嵌入(ru)式Linux系(xi)統(tong)--圖(tu)(tu)形(xing)(xing)庫(ku)(ku)，即Gui是用(yong)(yong)來做圖(tu)(tu)形(xing)(xing)面的(de)支撐庫(ku)(ku)。如Windows系(xi)統(tong)下(xia)的(de)“桌面”，“桌面”上的(de)圖(tu)(tu)標，都(dou)是用(yong)(yong)圖(tu)(tu)形(xing)(xing)庫(ku)(ku)來實現(xian)的(de)。你(ni)用(yong)(yong)的(de)手機顯(xian)示屏背景圖(tu)(tu)，顯(xian)示的(de)電話號碼，短(duan)信(xin)也都(dou)是基于圖(tu)(tu)形(xing)(xing)庫(ku)(ku)來實現(xian)的(de)。嵌入(ru)式Linux系(xi)統(tong)不一(yi)定用(yong)(yong)到圖(tu)(tu)形(xing)(xing)庫(ku)(ku)，所(suo)以(yi)圖(tu)(tu)形(xing)(xing)庫(ku)(ku)是嵌入(ru)式Linux系(xi)統(tong)可(ke)(ke)裁(cai)剪的(de)模塊之一(yi)，目前流行的(de)圖(tu)(tu)形(xing)(xing)庫(ku)(ku)有(you)QT/miniGUI/GTK+2/MFC，其(qi)中除了MFC都(dou)可(ke)(ke)以(yi)用(yong)(yong)在(zai)嵌入(ru)式Linux系(xi)統(tong)下(xia)。
嵌(qian)(qian)入(ru)式(shi)(shi)Linux系統--嵌(qian)(qian)入(ru)式(shi)(shi)數(shu)據(ju)(ju)庫(ku)(ku)(ku)，即(ji)Embeded Sql，是(shi)(shi)嵌(qian)(qian)入(ru)式(shi)(shi)Linux系統另(ling)重要的(de)(de)一(yi)個可(ke)裁(cai)剪模(mo)塊，就(jiu)是(shi)(shi)說有(you)些嵌(qian)(qian)入(ru)式(shi)(shi)Linux系統產品可(ke)能用(yong)(yong)到(dao)，有(you)些可(ke)能用(yong)(yong)不到(dao)，目前最流行(xing)的(de)(de)嵌(qian)(qian)入(ru)式(shi)(shi)數(shu)據(ju)(ju)庫(ku)(ku)(ku)就(jiu)是(shi)(shi) Sqlite。那么嵌(qian)(qian)入(ru)式(shi)(shi)數(shu)據(ju)(ju)庫(ku)(ku)(ku)到(dao)底做(zuo)什(shen)么用(yong)(yong)，如果(guo)你了(le)解數(shu)據(ju)(ju)庫(ku)(ku)(ku)，你可(ke)以把嵌(qian)(qian)入(ru)式(shi)(shi)數(shu)據(ju)(ju)庫(ku)(ku)(ku)看(kan)(kan)成(cheng)是(shi)(shi)一(yi)個小型的(de)(de)、輕量級的(de)(de)數(shu)據(ju)(ju)庫(ku)(ku)(ku)。如果(guo)不明白，請(qing)設想一(yi)個班的(de)(de)成(cheng)績單(dan)(表)，對(dui)每個學(xue)生成(cheng)績進(jin)行(xing)查(cha)看(kan)(kan)并做(zuo)排(pai)名，那么做(zuo)成(cheng)績單(dan)就(jiu)相當于(yu)存入(ru)數(shu)據(ju)(ju)庫(ku)(ku)(ku)，查(cha)看(kan)(kan)過程(cheng)就(jiu)相當于(yu)對(dui)數(shu)據(ju)(ju)庫(ku)(ku)(ku)進(jin)行(xing)搜(sou)索(檢索)，查(cha)看(kan)(kan)的(de)(de)結果(guo)就(jiu)像當于(yu)搜(sou)索(檢索)的(de)(de)結果(guo)，排(pai)名就(jiu)相當于(yu)對(dui)數(shu)據(ju)(ju)庫(ku)(ku)(ku)成(cheng)員(yuan)按名次創建索引。說的(de)(de)簡潔(jie)點-“數(shu)據(ju)(ju)庫(ku)(ku)(ku)就(jiu)是(shi)(shi)表和表的(de)(de)操作”。
看完了上面這些嵌入式linux系統概念及學習順序，是不是對他有一個初步的了解，想要知道更多，比較推薦華清遠見哦，而且在這里還有學習(xi)路線推薦給你哦，可以咨(zi)詢客服哦。
