用crosstool 制作交叉编译工具链
下面是用crosstools制作交叉编译工具链，
以下是编译过程：
  whw@whw-Aspire-4752:~/toolchain-build$ sudo ../toolchain-install/bin/ct-ng build
[INFO ] Performing some trivial sanity checks
[INFO ] Build started 20111215.183007
[INFO ] Building environment variables
[EXTRA] Preparing working directories
[EXTRA] Installing user-supplied crosstool-NG configuration
[EXTRA] =================================================================
[EXTRA] Dumping internal crosstool-NG configuration
[EXTRA] Building a toolchain for:
[EXTRA] build = x86_64-unknown-linux-gnu
[EXTRA] host = x86_64-unknown-linux-gnu
[EXTRA] target = arm-unknown-linux-gnueabi
[EXTRA] Dumping internal crosstool-NG configuration: done in 0.14s (at 00:10)
[INFO ] =================================================================
[INFO ] Retrieving needed toolchain components' tarballs
[INFO ] Retrieving needed toolchain components' tarballs: done in 0.13s (at 00:10)
[INFO ] =================================================================
[INFO ] Extracting and patching toolchain components
[INFO ] Extracting and patching toolchain components: done in 16.14s (at 00:26)
[INFO ] =================================================================
[INFO ] Installing GMP
[EXTRA] Configuring GMP
[EXTRA] Building GMP
[EXTRA] Installing GMP
[INFO ] Installing GMP: done in 104.41s (at 02:11)
[INFO ] =================================================================
[INFO ] Installing MPFR
[EXTRA] Configuring MPFR
[EXTRA] Building MPFR
[EXTRA] Installing MPFR
[INFO ] Installing MPFR: done in 21.51s (at 02:32)
[INFO ] =================================================================
[INFO ] Installing PPL
[EXTRA] Configuring PPL
[EXTRA] Building PPL
[EXTRA] Installing PPL
[INFO ] Installing PPL: done in 200.58s (at 05:53)
[INFO ] =================================================================
[INFO ] Installing CLooG/ppl
[EXTRA] Configuring CLooG/ppl
[EXTRA] Building CLooG/ppl
[EXTRA] Installing CLooG/ppl
[INFO ] Installing CLooG/ppl: done in 6.73s (at 05:59)
[INFO ] =================================================================
[INFO ] Installing binutils
[EXTRA] Configuring binutils
[EXTRA] Building binutils
[EXTRA] Installing binutils
[INFO ] Installing binutils: done in 54.53s (at 06:54)
[INFO ] =================================================================
[INFO ] Installing static core C compiler
[EXTRA] Configuring static core C compiler
[EXTRA] Building static core C compiler
[EXTRA] Installing static core C compiler
[INFO ] Installing static core C compiler: done in 138.29s (at 09:12)
[INFO ] =================================================================
[INFO ] Installing kernel headers
[EXTRA] Installing kernel headers
[EXTRA] Checking installed headers
[INFO ] Installing kernel headers: done in 7.88s (at 09:20)
[INFO ] =================================================================
[INFO ] Installing C library headers & start files
[EXTRA] Configuring C library
[EXTRA] Installing C library headers
[EXTRA] Installing C library start files
[INFO ] Installing C library headers & start files: done in 40.89s (at 10:01)
[INFO ] =================================================================
[INFO ] Installing shared core C compiler
[EXTRA] Configuring shared core C compiler
[EXTRA] Building shared core C compiler
[EXTRA] Installing shared core C compiler
[INFO ] Installing shared core C compiler: done in 151.75s (at 12:33)
[INFO ] ==============