【正文】 lly another boot loader called PMON, it wasn39。ll find a trx. A trx is just an encapsulation, which looks something like this Code:[ HDR0 ][ length ][ crc32 ][ flags ][ pointers ][ data ... ]HDR0 is a magic value to indicate a trx header, rest is 4 byte unsigned values followed by the actual contents. In short, it39。d lzma)(lzma39。s unable to remove the original package from squashfs。s not a seemless upgrade between releases. Having squashfs gives you a failsafe mechanism where you can always ignore the jffs2 partition and boot directly off squashfs, or restore files to their original squashfs versions.I used to have a trick where I could convert a squashfs install to a jffs2 install at runtime by copying all the data onto the squashfs partition and changing the partition boundaries. I never really had。ve implemented a policy that after each reflash the jffs2 data is reformatted. The trick to doing that is a special value, 0xdeadc0de。d lzma depress)(lzma39。 this can be triggered by the firmware not matching the firmware checksum, the boot_wait variable or via CFE39。t the firmware or we39。需要注意：l 盡量使用有線連接l 盡量使用HTTP，而不要使用HTTPS 通過TFTP安裝如果你非常小心，或者要從一次失敗的升級中重新更新映像，則可以使用tftp方式來安裝固件。(1) 啟用內(nèi)核選項可以通過修改build_mipsel/linux/.config來啟用相應(yīng)內(nèi)核選項，或者通過如下命令：$ cd build_mipsel/linux$ make menuconfig，這樣配置的參數(shù)就不會在make dirclean后丟失。(6) Makefile實例最后是最難的部分，創(chuàng)建Makefile。 擴展OpenWrt使用更多的軟件本小節(jié)主要是考慮你想加入更多的用戶空間的軟件，以加入軟件包foo為例：(1) 創(chuàng)建foo目錄在package/目錄中創(chuàng)建你的軟件包所對應(yīng)的目錄。為了建立該目錄，其會首先被刪除，將后將target/default/target_skeleton位置的綱要復(fù)制過去，最后刪除無用的SVN/目錄。(3) 創(chuàng)建toolchain編譯目錄（默認為toolchain_build_ARCH/）。l toolchain小節(jié)（在toolchain/目錄）：包含與交叉編譯環(huán)境相關(guān)的Makefiles和文件庫。(3) 。不過整個文件系統(tǒng)的層次結(jié)構(gòu)還不存在，因為其是在編譯過程中生成的。Squashfs包含一個只讀的文件系統(tǒng)，其為對使用了LZMA壓縮的squashfs文件系統(tǒng)的修改版本。當配置完成，以保存配置參數(shù)。就像上面說的，運行在你自己系統(tǒng)上的編譯工具鏈生成的二進制可執(zhí)行文件是運行在你自己主機系統(tǒng)上處理器上的。3 編譯配置新固件 介紹OpenWrt Buildroot 關(guān)于OpenWrt BuildrootOpenWrt Buildroot是一組Makefiles和補丁文件，這些文件可以使用用戶很容易的生成交叉編譯toolchain以及用于Wireless Router的根文件系統(tǒng)。經(jīng)過測試，來修改HustSupplicant所模擬的認證版本。包括這可能就是原因吧。這可以降低程序移植的難度和工作量。對于本路由器的一可用的較新版本是：下載地址為：解壓后即可獲得所需要交流編譯工具集。建議所以配置均通過web界面進行，因為其可以自動保存有關(guān)參數(shù)。 技術(shù)文檔Linksys WRT54G使用指南 blckstone20097111 基本運行環(huán)境 硬件平臺 Linksys WRT54G V4CPU 200MHz Broad BCM5352 chip rev0SDRAM: 16MFlash: 4M具體說明：The BCM5352EL integrates a highperformance MIPS32 processor, IEEE b/g MAC/PHY, SDRAM controller, and a configurable fiveport Fast Ethernet (FE) switch. The BCM5352EL provides wireless LAN connectivity supporting data rates of up to 125 Mbps that is backwardpatible with standard b/g. The BCM5352EL supports a WAN connection via its configurable media interfaces. The perport programmable fourlevel priority queues enable QoS (IEEE ) for guaranteed bandwidth applications, DiffServ/TOS, and L2/L3 IGMP snooping. The IEEE VLAN allows flexible implementation of VLAN grouping and WAN port segregation.特征200MHz MIPS32174。 配置路由器 通過web界面管理路由器路由器默認的網(wǎng)絡(luò)參數(shù)如下：Lan IP: Mask: web管理入口： 用戶名密碼：root/admin通過web界面可進行常規(guī)的參數(shù)配置。 Whiterussian系列 Kamikaze系列， 搭建交叉編譯環(huán)境 搭建可用主機環(huán)境安裝好可以編譯的主機環(huán)境，并在上面安裝好相應(yīng)的Apache2服務(wù)、samba服務(wù)等，方便后繼的與路由器的數(shù)據(jù)交換！ 獲取交叉編譯工具鏈。另外，本HustSupplicant不依賴其它特定的包，一般是只使用標準C函數(shù)。則該組播幀似乎就被交換機給屏蔽了。據(jù)我所知目前使用這個芯片的機器只有 Linksys WRT54G/GS 系列的前兩個版本，還有 Moto WR850G v2 ，Dell TrueMobile 2300 的某一個版本，其它的都不行了。但是在光電國家實驗室這邊的網(wǎng)絡(luò)中，似乎交換機較新，因此其對認證程序的版本就有一定要求。另外認證程序還不能自動獲得當前運行環(huán)境中的指定網(wǎng)卡的IP信息和掩碼信息。這樣主機編譯工具鏈是由你的發(fā)行版提供的，openwrt不會對其做任何事情。編譯的過程如下：(1) 配置$make menuconfig在配置選項中的每一項，你都可以獲得相關(guān)的幫助來了解對應(yīng)條目的作用。l Squashfs。你可以在這里定制配置文件及其它事情。修改uClibc最簡單的方式如下：(1) 在沒有對uClibc進行任何配置的情況下進行一次buildroot編譯(2) 改變當前目錄到toolchain_build_ARCH/uClibc/目錄，然后運行make 。每個子目錄代表一種工具。該目錄用于編譯用戶空間的工具。該目錄將會包含最終的目標根文件系統(tǒng)。 下載的軟件包的位置默認情況下下載的軟件都位于/dl目錄中。其中Depends域非常重要，這樣ipkg工具將會在目標系統(tǒng)上自動獲取所有依賴軟件。In Line 3 and 17 we include mon variables and routines to simplify the process of ipkg creation. It includes routines to download, verify and extract the software package archives.Line 19 contains the magic line which automatically creates the ipkg for us.Lines 2133 defines a target and associated rules that configures the software. It depends on the previous target (the hidden .prepared file) so that we are sure the software has been unpressed. In order to configure it, it basically runs the wellknown ./configurescript. As we may be doing crosspilation, target, host and build arguments are given. The prefix is also set to /usr, not because the software will be installed in /usr on your host system, but in the target filesystem. Finally it creates a .configured file to mark the software as configured.Lines 3542 defines a target and a rule that piles the software. This target will create the binary file in the pilation directory, and depends on the software being already configured (hence the reference to the .configured file). Afterwards it installs the resulting binary into the PKG_INSTALL_DIR. It basically runs make install inside the source directory.Lines 4450 defines a target and associated rules that create the ipkg package, which can optionally be embedded into the resulting firmware image. It manually installs all files you want to integrate in your resulting ipkg. RSTRIP will recursevily strip all binaries and libraries. Finally IPKG_BUILD is called to create the package. OpenWrt 內(nèi)核模塊創(chuàng)建本小節(jié)將主要介紹如何進行OpenWrt的內(nèi)核模塊的創(chuàng)建，使其成為安裝成為ipkg。安裝過程可能出現(xiàn)的問題及解決方法，見：(2f) 通過廠商提供的WEB界面安裝這是最簡單的方式，即通過WEB管理界面直接升級映像。 at power up the CPU begins executing the code at the very start of flash. Luckily this isn39。t render the device useless. CFE does this through the use of a TFTP server。s a highly pressed readonly filesystem remember that altering the contents of the trx in any way would invalidate the crc, so we put our writable data in a jffs2 partition ouside the trx. This means that our firmware looks like this:Code:[trx (gzip39。s not all without side effects however The fact that we pack things so tightly in flash means that if the firmware ever changes, the size and location of the