1. 問題簡介
最近在ubuntu 18.04 64位系統上搭建iTop4412的開發環境，將交叉編譯工具鏈解壓的指定位置並修改系統PATH變量後，運行arm-none-linux-gnueabi-gcc -v還是一直提示No Such File or Directory，直接在文件所在目錄運行./arm-none-linux-gnueabi-gcc -v也是報一樣的錯誤，所有文件都有可執行權限，這明顯就不是找不到文件的問題了，明顯是搞事情…
2. 原因分析
查資料的時候有大神提到交叉編譯工具鏈文件是有32位和64位區分的，趕緊查了查我的工具鏈，果然是32位的。
linux@ubuntu:/usr/local/arm/arm-2009q3/bin$ file arm-none-linux-gnueabi-gcc
arm-none-linux-gnueabi-gcc: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-, for GNU/Linux 2.2.5, stripped
3. 系統安裝32位支持
既然確定了原因，那就安裝對應的庫，讓64位系統支持32位工具鏈。
sudo dpkg --add-architecture i386
sudo apt-get update
sudo apt-get install libc6:i386
sudo apt-get install lib32ncurses5 lib32ncurses5-dev
sudo apt-get install lib32z1
驗證通過，搞定。
linux@ubuntu:/usr/local/arm/arm-2009q3/bin$ arm-none-linux-gnueabi-gcc -v
Using built-in specs.
Target: arm-none-linux-gnueabi
Configured with: /scratch/julian/2009q3-respin-linux-lite/src/gcc-4.4/configure --build=i686-pc-linux-gnu --host=i686-pc-linux-gnu --target=arm-none-linux-gnueabi --enable-threads --disable-libmudflap --disable-libssp --disable-libstdcxx-pch --enable-extra-sgxxlite-multilibs --with-arch=armv5te --with-gnu-as --with-gnu-ld --with-specs='%{funwind-tables|fno-unwind-tables|mabi=*|ffreestanding|nostdlib:;:-funwind-tables} %{O2:%{!fno-remove-local-statics: -fremove-local-statics}} %{O*:%{O|O0|O1|O2|Os:;:%{!fno-remove-local-statics: -fremove-local-statics}}}' --enable-languages=c,c++ --enable-shared --disable-lto --enable-symvers=gnu --enable-__cxa_atexit --with-pkgversion='Sourcery G++ Lite 2009q3-67' --with-bugurl=https://support.codesourcery.com/GNUToolchain/ --disable-nls --prefix=/opt/codesourcery --with-sysroot=/opt/codesourcery/arm-none-linux-gnueabi/libc --with-build-sysroot=/scratch/julian/2009q3-respin-linux-lite/install/arm-none-linux-gnueabi/libc --with-gmp=/scratch/julian/2009q3-respin-linux-lite/obj/host-libs-2009q3-67-arm-none-linux-gnueabi-i686-pc-linux-gnu/usr --with-mpfr=/scratch/julian/2009q3-respin-linux-lite/obj/host-libs-2009q3-67-arm-none-linux-gnueabi-i686-pc-linux-gnu/usr --with-ppl=/scratch/julian/2009q3-respin-linux-lite/obj/host-libs-2009q3-67-arm-none-linux-gnueabi-i686-pc-linux-gnu/usr --with-host-libstdcxx='-static-libgcc -Wl,-Bstatic,-lstdc++,-Bdynamic -lm' --with-cloog=/scratch/julian/2009q3-respin-linux-lite/obj/host-libs-2009q3-67-arm-none-linux-gnueabi-i686-pc-linux-gnu/usr --disable-libgomp --enable-poison-system-directories --with-build-time-tools=/scratch/julian/2009q3-respin-linux-lite/install/arm-none-linux-gnueabi/bin --with-build-time-tools=/scratch/julian/2009q3-respin-linux-lite/install/arm-none-linux-gnueabi/bin
Thread model: posix
gcc version 4.4.1 (Sourcery G++ Lite 2009q3-67)