Cross Compile libdnet and Python for Montavista/PowerPC

Cross Compile libdnet and Python for Montavista/PowerPC

Peter Jiangsy

一开始我是想把Python 2.5.1交叉编译，以运行在Montavista/PowerPC上，但是一直不成功。于是我想到了先编译一些相对比较小的程序，因为我原本是希望利用自己以前使用Python+Libdnet的经验，在Montavista/PowerPC上做一些开发，所以我就拿了Libdnet开刀。

一开始经过了很多的失败，在网上寻找“Cross Compile Python”和“Cross Compile PowerPC”也没有找到什么好的参考。不过后来不知道搜什么后，我在网上看到了Cross Compile libcurl的文章，这也是在PPC上交叉编译，很简短，摘录如下。

CROSS COMPILE libcurl CROSS COMPILE =============      (This section was graciously brought to us by Jim Duey, with additions by    Dan Fandrich)      Download and unpack the cURL package.  Version should be 7.9.1 or later.      'cd' to the new directory. (e.g. cd curl-7.12.3)      Set environment variables to point to the cross-compile toolchain and call    configure with any options you need.  Be sure and specify the '--host' and    '--build' parameters at configuration time.  The following script is an    example of cross-compiling for the IBM 405GP PowerPC processor using the    toolchain from MonteVista for Hardhat Linux.      (begin script)   #!  /bin/sh      export PATH=$PATH:/opt/hardhat/devkit/ppc/405/bin    export CPPFLAGS="-I/opt/hardhat/devkit/ppc/405/target/usr/include"    export AR=ppc_405-ar    export AS=ppc_405-as    export LD=ppc_405-ld    export RANLIB=ppc_405-ranlib    export CC=ppc_405-gcc    export NM=ppc_405-nm      ./configure --target=powerpc-hardhat-linux                --host=powerpc-hardhat-linux                --build=i586-pc-linux-gnu                --prefix=/opt/hardhat/devkit/ppc/405/target/usr/local                --exec-prefix=/usr/local      (end script)      You may also need to provide a parameter like '--with-random=/dev/urandom'    to configure as it cannot detect the presence of a random number    generating device for a target system.  The '--prefix' parameter    specifies where cURL will be installed.  If 'configure' completes    successfully, do 'make' and 'make install' as usual.      In some cases, you may be able to simplify the above commands to as    little as:          ./configure --host=ARCH-OS      There are a number of configure options that can be used to reduce the    size of libcurl for embedded applications where binary size is an    important factor.  First, be sure to set the CFLAGS environment variable    when configuring with any compiler optimization flags to reduce the    size of the binary.  For gcc, this would mean at minimum:         env CFLAGS='-Os' ./configure ...      Be sure to specify as many --disable- and --without- flags on the configure    command-line as you can to disable all the libcurl features that you    know your application is not going to need.  Besides specifying the    --disable-PROTOCOL flags for all the types of URLs your application    will not use, here are some other flags that can reduce the size of the    library:        --disable-ares (disables support for the ARES DNS library)      --disable-cookies (disables support for HTTP cookies)      --disable-crypto-auth (disables HTTP cryptographic authentication)      --disable-ipv6 (disables support for IPv6)      --disable-verbose (eliminates debugging strings and error code strings)      --without-libidn (disables support for the libidn DNS library)      --without-ssl (disables support for SSL/TLS)      --without-zlib (disables support for on-the-fly decompression)      You may find that statically linking libcurl to your application will    result in a lower total size.     PORTS =====    This is a probably incomplete list of known hardware and operating systems    that curl has been compiled for. If you know a system curl compiles and    runs on, that isn't listed, please let us know!           - Alpha DEC OSF 4         - Alpha Digital UNIX v3.2         - Alpha FreeBSD 4.1, 4.5         - Alpha Linux 2.2, 2.4         - Alpha NetBSD 1.5.2         - Alpha OpenBSD 3.0         - Alpha OpenVMS V7.1-1H2         - Alpha Tru64 v5.0 5.1         - HP-PA HP-UX 9.X 10.X 11.X         - HP-PA Linux         - HP3000 MPE/iX         - MIPS IRIX 6.2, 6.5         - MIPS Linux         - Pocket PC/Win CE 3.0         - Power AIX 3.2.5, 4.2, 4.3.1, 4.3.2, 5.1, 5.2         - PowerPC Darwin 1.0         - PowerPC Linux         - PowerPC Mac OS 9         - PowerPC Mac OS X         - SINIX-Z v5         - Sparc Linux         - Sparc Solaris 2.4, 2.5, 2.5.1, 2.6, 7, 8, 9, 10         - Sparc SunOS 4.1.X         - StrongARM (and other ARM) RISC OS 3.1, 4.02         - StrongARM/ARM7/ARM9 Linux 2.4, 2.6         - StrongARM NetBSD 1.4.1         - Ultrix 4.3a         - i386 BeOS         - i386 DOS         - i386 Esix 4.1         - i386 FreeBSD         - i386 HURD         - i386 Linux 1.3, 2.0, 2.2, 2.3, 2.4, 2.6         - i386 NetBSD         - i386 Novell NetWare         - i386 OS/2         - i386 OpenBSD         - i386 SCO unix         - i386 Solaris 2.7         - i386 Windows 95, 98, ME, NT, 2000, XP, 2003         - i386 QNX 6         - i486 ncr-sysv4.3.03 (NCR MP-RAS)         - ia64 Linux 2.3.99         - m68k AmigaOS 3         - m68k Linux         - m68k OpenBSD         - m88k dg-dgux5.4R3.00         - s390 Linux         - XScale/PXA250 Linux 2.4

 

这个文章给了我很大的启发，于是我参考它，在下载并解压libdnet 1.11之后，写了如下的脚本以编译libdnet：

[jiangsy@MontaVista libdnet-1.11]$ ./configure CC=ppc_85xx-gcc RANLIB=ppc_85xx-ranlib CPP=ppc_85xx-cpp AR=ppc_85xx-ar AS=ppc_85xx-as STRIP=ppc_85xx-strip LD=ppc_85xx-ld CXX=ppc_85xx-c++ GXX=ppc_85xx-g++ --prefix=/opt/montavista/pro/devkit/ppc/85xx/target/usr/local/ --host= ppc_85xx configure: WARNING: If you wanted to set the --build type, don't use --host.     If a cross compiler is detected then cross compile mode will be used. checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for powerpc-ppc85xx-linux2.4.20-strip... ppc_85xx-strip checking whether to enable maintainer-specific portions of Makefiles... no checking build system type... i686-pc-linux-gnu checking host system type... powerpc-ppc85xx-linux-gnu2.4.20 checking for powerpc-ppc85xx-linux2.4.20-gcc... ppc_85xx-gcc checking for C compiler default output file name... configure: error: C compiler cannot create executables See `config.log' for more details. [jiangsy@MontaVista libdnet-1.11]$

 

这个脚本中的好几个地方是学来的，例如“--prefix”这个选项，我知道应该设定为交叉编译toolchain工具链中的“/target/usr/local”目录，这里就是“/opt/montavista/pro/devkit/ppc/85xx/target/usr/local/”。

从脚本运行的Warning提示我们可以看出，Autoconf支持了cross-compile概念，通过“--build”，“--host”以及“--target”等选项帮助cross compile。

值得一提的是一开始学习搬用“--target”和“--host”这两个选项的时候，之前我一直不知道该怎么写，于是我自作主张，使用“ppc_85xx-gcc”的前缀“ppc_85xx”作为值，因为我发现“STRIP”这个工具需要使用“--host”的值作为前缀。结果出现了“machine `ppc_85xx' not recognized”错误。于是我又参考上文，将“--host”设定为“powerpc-ppc85xx-linux2.4.20”，我只是生搬硬套，同时将linux版本号改成我们的ICM3G使用的2.4.20而已。解决了这个问题，而且，“./configure”之后，编译系统得出了“powerpc-ppc85xx-linux-gnu2.4.20”这个信息，我很奇怪它怎么得到的。

export PATH=$PATH:/opt/montavista/pro/devkit/ppc/85xx/bin/ export CPPFLAGS="/opt/montavista/pro/devkit/ppc/85xx/include/" export AR=ppc_85xx-ar export AS=ppc_85xx-as export LD=ppc_85xx-ld export RANLIB=ppc_85xx-ranlib export CC=ppc_85xx-gcc export NM=ppc_85xx-nm export CPP=ppc_85xx-cpp export CXX=ppc_85xx-c++ export GXX=ppc_85xx-g++ export STRIP=ppc_85xx-strip   ./configure --target=powerpc-ppc85xx-linux2.4.20 /             --host=powerpc-ppc85xx-linux2.4.20 /             --build=i686-pc-linux-gnu /             --prefix=/opt/montavista/pro/devkit/ppc/85xx/target/usr/local/ /             --exec-prefix=/usr/local

 

这里我换了一种写法，把“export”语句独立出来了，具体的参考文档已经无处寻觅了。

另外，对于“STRIP”的问题，系统自动使用“--host”的值去试图使用“powerpc-ppc85xx-linux2.4.20-strip”，虽然不会中断“./configure”进程，但是会出现“no”的提示。如果设定了“STRIP=ppc_85xx-strip”，就可以解决问题。这里“--target”选项删除了，也不会影响编译。

这个脚本的执行结果出现了错误“checking for C compiler default output file name... configure: error: C compiler cannot create executables”。通过查看“config.log”，发现了如下的语句：

configure:2337: checking for C compiler default output file name configure:2340: ppc_85xx-gcc  /opt/montavista/pro/devkit/ppc/85xx/include/  conftest.c  >&5 /opt/montavista/pro/devkit/ppc/85xx/include/: file not recognized: Is a directory collect2: ld returned 1 exit status configure:2343: $? = 1 configure: failed program was: | /* confdefs.h.  */ | | #define PACKAGE_NAME "" | #define PACKAGE_TARNAME "" | #define PACKAGE_VERSION "" | #define PACKAGE_STRING "" | #define PACKAGE_BUGREPORT "" | #define PACKAGE "libdnet" | #define VERSION "1.11" | /* end confdefs.h.  */ | | int | main () | { | |   ; |   return 0; | } configure:2382: error: C compiler cannot create executables See `config.log' for more details.

我看了之后，把“export CPPFLAGS="/opt/montavista/pro/devkit/ppc/85xx/include/"”修改成“export CPPFLAGS=”，空的，就解决了。而且最后编译成功了。

所以最后的可用的最小命令集合就是：

export PATH=$PATH:/opt/montavista/pro/devkit/ppc/85xx/bin/ export CPPFLAGS= export AR=ppc_85xx-ar export AS=ppc_85xx-as export LD=ppc_85xx-ld export RANLIB=ppc_85xx-ranlib export CC=ppc_85xx-gcc export NM=ppc_85xx-nm export CPP=ppc_85xx-cpp export CXX=ppc_85xx-c++ export GXX=ppc_85xx-g++ export STRIP=ppc_85xx-strip   ./configure --host=powerpc-ppc85xx-linux2.4.20 /             --build=i686-pc-linux-gnu /             --prefix=/opt/montavista/pro/devkit/ppc/85xx/target/usr/local/ /             --exec-prefix=/usr/local

这些其实就是交叉编译比普通linux上编译的多余的步骤。我这里姑且称他们为“PPC交叉编译前奏”。

 

最后的输出，虽然比较多，但是也摘录下来，可以做参考。如下：

checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for powerpc-ppc85xx-linux2.4.20-strip... ppc_85xx-strip checking whether to enable maintainer-specific portions of Makefiles... no checking build system type... i686-pc-linux-gnu checking host system type... powerpc-ppc85xx-linux-gnu2.4.20 checking for powerpc-ppc85xx-linux2.4.20-gcc... ppc_85xx-gcc checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... yes checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether ppc_85xx-gcc accepts -g... yes checking for ppc_85xx-gcc option to accept ANSI C... none needed checking for style of include used by make... GNU checking dependency style of ppc_85xx-gcc... none checking for a BSD-compatible install... /usr/bin/install -c checking for a sed that does not truncate output... /bin/sed checking for egrep... grep -E checking for ld used by ppc_85xx-gcc... ppc_85xx-ld checking if the linker (ppc_85xx-ld) is GNU ld... yes checking for ppc_85xx-ld option to reload object files... -r checking for BSD-compatible nm... ppc_85xx-nm checking whether ln -s works... yes checking how to recognise dependent libraries... pass_all checking how to run the C preprocessor... ppc_85xx-cpp checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking dlfcn.h usability... yes checking dlfcn.h presence... yes checking for dlfcn.h... yes checking for powerpc-ppc85xx-linux2.4.20-ppc_85xx-g++... ppc_85xx-c++ checking whether we are using the GNU C++ compiler... no checking whether ppc_85xx-c++ accepts -g... no checking dependency style of ppc_85xx-c++... none checking how to run the C++ preprocessor... /lib/cpp checking for powerpc-ppc85xx-linux2.4.20-g77... no checking for powerpc-ppc85xx-linux2.4.20-f77... no checking for powerpc-ppc85xx-linux2.4.20-xlf... no checking for powerpc-ppc85xx-linux2.4.20-frt... no checking for powerpc-ppc85xx-linux2.4.20-pgf77... no checking for powerpc-ppc85xx-linux2.4.20-fort77... no checking for powerpc-ppc85xx-linux2.4.20-fl32... no checking for powerpc-ppc85xx-linux2.4.20-af77... no checking for powerpc-ppc85xx-linux2.4.20-f90... no checking for powerpc-ppc85xx-linux2.4.20-xlf90... no checking for powerpc-ppc85xx-linux2.4.20-pgf90... no checking for powerpc-ppc85xx-linux2.4.20-epcf90... no checking for powerpc-ppc85xx-linux2.4.20-f95... no checking for powerpc-ppc85xx-linux2.4.20-fort... no checking for powerpc-ppc85xx-linux2.4.20-xlf95... no checking for powerpc-ppc85xx-linux2.4.20-ifc... no checking for powerpc-ppc85xx-linux2.4.20-efc... no checking for powerpc-ppc85xx-linux2.4.20-pgf95... no checking for powerpc-ppc85xx-linux2.4.20-lf95... no checking for powerpc-ppc85xx-linux2.4.20-gfortran... no checking for g77... g77 checking whether we are using the GNU Fortran 77 compiler... yes checking whether g77 accepts -g... yes checking the maximum length of command line arguments... 32768 checking command to parse ppc_85xx-nm output from ppc_85xx-gcc object... ok checking for objdir... .libs checking for powerpc-ppc85xx-linux2.4.20-ar... ppc_85xx-ar checking for powerpc-ppc85xx-linux2.4.20-ranlib... ppc_85xx-ranlib checking for powerpc-ppc85xx-linux2.4.20-strip... (cached) ppc_85xx-strip checking if ppc_85xx-gcc static flag  works... yes checking if ppc_85xx-gcc supports -fno-rtti -fno-exceptions... no checking for ppc_85xx-gcc option to produce PIC... -fPIC checking if ppc_85xx-gcc PIC flag -fPIC works... yes checking if ppc_85xx-gcc supports -c -o file.o... yes checking whether the ppc_85xx-gcc linker (ppc_85xx-ld) supports shared libraries... yes checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking dynamic linker characteristics... GNU/Linux ld.so checking for shl_load... no checking for shl_load in -ldld... no checking for dlopen... no checking for dlopen in -ldl... yes checking whether a program can dlopen itself... cross checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... yes configure: creating libtool appending configuration tag "CXX" to libtool checking whether the ppc_85xx-c++ linker (ppc_85xx-ld) supports shared libraries... yes libtool.m4: error: problem compiling CXX test program checking for ppc_85xx-c++ option to produce PIC... checking if ppc_85xx-c++ supports -c -o file.o... no checking whether the ppc_85xx-c++ linker (ppc_85xx-ld) supports shared libraries... yes checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking dynamic linker characteristics... GNU/Linux ld.so checking for shl_load... (cached) no checking for shl_load in -ldld... (cached) no checking for dlopen... (cached) no checking for dlopen in -ldl... (cached) yes checking whether a program can dlopen itself... (cached) cross appending configuration tag "F77" to libtool checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... yes checking for g77 option to produce PIC... -fPIC checking if g77 PIC flag -fPIC works... yes checking if g77 supports -c -o file.o... yes checking whether the g77 linker (ppc_85xx-ld) supports shared libraries... yes checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking dynamic linker characteristics... GNU/Linux ld.so checking for Python... checking for gethostbyname... yes checking for socket... yes checking for putmsg in -lstr... no checking for open_mib in -lnm... no checking for Check... no checking for ANSI C header files... (cached) yes checking fcntl.h usability... yes checking fcntl.h presence... yes checking for fcntl.h... yes checking for unistd.h... (cached) yes checking sys/bufmod.h usability... no checking sys/bufmod.h presence... no checking for sys/bufmod.h... no checking sys/dlpi.h usability... no checking sys/dlpi.h presence... no checking for sys/dlpi.h... no checking sys/dlpihdr.h usability... no checking sys/dlpihdr.h presence... no checking for sys/dlpihdr.h... no checking sys/dlpi_ext.h usability... no checking sys/dlpi_ext.h presence... no checking for sys/dlpi_ext.h... no checking sys/ioctl.h usability... yes checking sys/ioctl.h presence... yes checking for sys/ioctl.h... yes checking sys/mib.h usability... no checking sys/mib.h presence... no checking for sys/mib.h... no checking sys/ndd_var.h usability... no checking sys/ndd_var.h presence... no checking for sys/ndd_var.h... no checking sys/socket.h usability... yes checking sys/socket.h presence... yes checking for sys/socket.h... yes checking sys/sockio.h usability... no checking sys/sockio.h presence... no checking for sys/sockio.h... no checking sys/sysctl.h usability... yes checking sys/sysctl.h presence... yes checking for sys/sysctl.h... yes checking sys/time.h usability... yes checking sys/time.h presence... yes checking for sys/time.h... yes checking net/bpf.h usability... yes checking net/bpf.h presence... yes checking for net/bpf.h... yes checking net/if.h usability... yes checking net/if.h presence... yes checking for net/if.h... yes checking net/if_var.h usability... no checking net/if_var.h presence... no checking for net/if_var.h... no checking net/if_arp.h usability... yes checking net/if_arp.h presence... yes checking for net/if_arp.h... yes checking net/if_dl.h usability... no checking net/if_dl.h presence... no checking for net/if_dl.h... no checking net/pfilt.h usability... no checking net/pfilt.h presence... no checking for net/pfilt.h... no checking net/pfvar.h usability... no checking net/pfvar.h presence... no checking for net/pfvar.h... no checking net/radix.h usability... no checking net/radix.h presence... no checking for net/radix.h... no checking net/raw.h usability... no checking net/raw.h presence... no checking for net/raw.h... no checking net/route.h usability... yes checking net/route.h presence... yes checking for net/route.h... yes checking netinet/in_var.h usability... no checking netinet/in_var.h presence... no checking for netinet/in_var.h... no checking net/if_tun.h usability... no checking net/if_tun.h presence... no checking for net/if_tun.h... no checking linux/if_tun.h usability... yes checking linux/if_tun.h presence... yes checking for linux/if_tun.h... yes checking netinet/ip_fw.h usability... no checking netinet/ip_fw.h presence... no checking for netinet/ip_fw.h... no checking linux/ip_fw.h usability... no checking linux/ip_fw.h presence... no checking for linux/ip_fw.h... no checking linux/ip_fwchains.h usability... no checking linux/ip_fwchains.h presence... no checking for linux/ip_fwchains.h... no checking linux/netfilter_ipv4/ipchains_core.h usability... no checking linux/netfilter_ipv4/ipchains_core.h presence... yes configure: WARNING: linux/netfilter_ipv4/ipchains_core.h: present but cannot be compiled configure: WARNING: linux/netfilter_ipv4/ipchains_core.h:     check for missing prerequisite headers? configure: WARNING: linux/netfilter_ipv4/ipchains_core.h: see the Autoconf documentation configure: WARNING: linux/netfilter_ipv4/ipchains_core.h:     section "Present But Cannot Be Compiled" configure: WARNING: linux/netfilter_ipv4/ipchains_core.h: proceeding with the preprocessor's result configure: WARNING: linux/netfilter_ipv4/ipchains_core.h: in the future, the compiler will take precedence configure: WARNING:     ## ------------------------------------------ ## configure: WARNING:     ## Report this to the AC_PACKAGE_NAME lists.  ## configure: WARNING:     ## ------------------------------------------ ## checking for linux/netfilter_ipv4/ipchains_core.h... yes checking ip_fil_compat.h usability... no checking ip_fil_compat.h presence... no checking for ip_fil_compat.h... no checking netinet/ip_fil_compat.h usability... no checking netinet/ip_fil_compat.h presence... no checking for netinet/ip_fil_compat.h... no checking ip_compat.h usability... no checking ip_compat.h presence... no checking for ip_compat.h... no checking netinet/ip_compat.h usability... no checking netinet/ip_compat.h presence... no checking for netinet/ip_compat.h... no checking ip_fil.h usability... no checking ip_fil.h presence... no checking for ip_fil.h... no checking netinet/ip_fil.h usability... no checking netinet/ip_fil.h presence... no checking for netinet/ip_fil.h... no checking hpsecurity.h usability... no checking hpsecurity.h presence... no checking for hpsecurity.h... no checking stropts.h usability... yes checking stropts.h presence... yes checking for stropts.h... yes checking for an ANSI C-conforming const... yes checking for inline... inline checking for pid_t... yes checking for size_t... yes checking for sockaddr_in6 struct in ... yes checking for sa_len in sockaddr struct... no checking for arp_dev in arpreq struct... yes checking for rt_msghdr struct in ... no checking whether ppc_85xx-gcc needs -traditional... no checking for working memcmp... no checking for err... yes checking for strlcat... no checking for strlcpy... no checking for strsep... yes checking for Berkeley Packet Filter... no checking for Linux proc filesystem... yes checking for Linux PF_PACKET sockets... yes checking for SNMP MIB2 STREAMS... no checking for route(7) STREAMS... no checking for arp(7) ioctls... yes checking for raw IP sockets ip_{len,off} host byte ordering... no checking for cooked raw IP sockets... no configure: creating ./config.status config.status: creating Makefile config.status: creating dnet-config config.status: creating include/Makefile config.status: creating include/dnet/Makefile config.status: creating man/Makefile config.status: creating src/Makefile config.status: creating python/Makefile config.status: creating python/setup.py config.status: creating test/Makefile config.status: creating test/check/Makefile config.status: creating test/dnet/Makefile config.status: creating include/config.h config.status: include/config.h is unchanged config.status: executing depfiles commands config.status: executing default commands [root@MontaVista libdnet-1.11]#

 

然后再通过“make –s”，得到了最终的dnet库。输出如下：

[root@MontaVista libdnet-1.11]# make -s Making all in include Making all in dnet Making all in man Making all in src mkdir .libs  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c addr-util.c  -fPIC -DPIC -o .libs/addr-util.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c addr-util.c -o addr-util.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c addr.c  -fPIC -DPIC -o .libs/addr.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c addr.c -o addr.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c blob.c  -fPIC -DPIC -o .libs/blob.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c blob.c -o blob.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c ip-util.c  -fPIC -DPIC -o .libs/ip-util.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c ip-util.c -o ip-util.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c ip6.c  -fPIC -DPIC -o .libs/ip6.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c ip6.c -o ip6.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c rand.c  -fPIC -DPIC -o .libs/rand.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c rand.c -o rand.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c memcmp.c  -fPIC -DPIC -o .libs/memcmp.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c memcmp.c -o memcmp.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c strlcat.c  -fPIC -DPIC -o .libs/strlcat.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c strlcat.c -o strlcat.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c strlcpy.c  -fPIC -DPIC -o .libs/strlcpy.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c strlcpy.c -o strlcpy.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c arp-ioctl.c  -fPIC -DPIC -o .libs/arp-ioctl.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c arp-ioctl.c -o arp-ioctl.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c eth-linux.c  -fPIC -DPIC -o .libs/eth-linux.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c eth-linux.c -o eth-linux.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c fw-ipchains.c  -fPIC -DPIC -o .libs/fw-ipchains.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c fw-ipchains.c -o fw-ipchains.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c intf.c  -fPIC -DPIC -o .libs/intf.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c intf.c -o intf.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c ip.c  -fPIC -DPIC -o .libs/ip.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c ip.c -o ip.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c route-linux.c  -fPIC -DPIC -o .libs/route-linux.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c route-linux.c -o route-linux.o >/dev/null 2>&1  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c tun-linux.c  -fPIC -DPIC -o .libs/tun-linux.o  ppc_85xx-gcc -DHAVE_CONFIG_H -I. -I. -I../include -I../include -g -O2 -Wall -c tun-linux.c -o tun-linux.o >/dev/null 2>&1 ppc_85xx-gcc -shared  .libs/addr-util.o .libs/addr.o .libs/blob.o .libs/ip-util.o .libs/ip6.o .libs/rand.o .libs/memcmp.o .libs/strlcat.o .libs/strlcpy.o .libs/arp-ioctl.o .libs/eth-linux.o .libs/fw-ipchains.o .libs/intf.o .libs/ip.o .libs/route-linux.o .libs/tun-linux.o  -lc  -Wl,-soname -Wl,libdnet.1 -o .libs/libdnet.1.0.1 (cd .libs && rm -f libdnet.1 && ln -s libdnet.1.0.1 libdnet.1) (cd .libs && rm -f libdnet && ln -s libdnet.1.0.1 libdnet) ppc_85xx-ar cru .libs/libdnet.a  addr-util.o addr.o blob.o ip-util.o ip6.o rand.o memcmp.o strlcat.o strlcpy.o arp-ioctl.o eth-linux.o fw-ipchains.o intf.o ip.o route-linux.o tun-linux.o ppc_85xx-ranlib .libs/libdnet.a creating libdnet.la (cd .libs && rm -f libdnet.la && ln -s ../libdnet.la libdnet.la) Making all in python Making all in test Making all in check Making all in dnet mkdir .libs ppc_85xx-gcc -g -O2 -Wall -o .libs/dnet addr.o arp.o aton.o dnet.o eth.o fw.o hex.o icmp.o intf.o ip.o rand.o route.o send.o tcp.o udp.o  ../../src/.libs/libdnet -Wl,--rpath -Wl,/usr/local/lib creating dnet [root@MontaVista libdnet-1.11]#

 

可以通过“make distclean”清除所有的最终文件和中间文件。

最后的输出就是：

[root@MontaVista libdnet-1.11]# ll /home1/jiangsy/libdnet-1.11/src/.libs/libdnet.a -rw-r--r--    1 root     root       170628 Sep 27 18:52 /home1/jiangsy/libdnet-1.11/src/.libs/libdnet.a

 

通过“ppc_85xx-objdump -d”导出的符号表可以看出具体的指令是属于PowerPC指令集的。如果我们直接采用x86-linux的gcc和make进行编译，具体的“./configure”以及“make –s”的不同可以通过输出进行比较，参见pc.configure.txt和ppc.configure.txt。最终得到的libdnet.a为：

	[root@MontaVista libdnet-1.11]# ll /home1/jiangsy/libdnet-1.11/src/.libs/libdnet.a -rw-r--r--    1 root     root       519550 Sep 27 19:02 /home1/jiangsy/libdnet-1.11/src/.libs/libdnet.a
	-rw-r--r--    1 root     root       309100 Sep 27 19:04 libdnet.sym.pc -rw-r--r--    1 root     root       240750 Sep 27 19:04 libdnet.sym.ppc
	X86-PC和PowerPC不同的“./configure”输出记录：
	符号表我就不嵌入进来了。不过应该都是完整的，因为我在两个符号表中都查找到了其中的一个函数。

 

两个libdnet.a的文件大小差别很大，到底会不会是交叉编译失败了呢？具体的回答，只能在以后使用的时候做解答了。不过两者的符号表大小相差不大。

我这些是通过“su”到“root”用户执行的。

 

编译libdnet成功之后，我有信心重新去交叉编译（cross compile）python 2.5.1了。我使用跟上面一样的命令集合，结果还是出现了下面的错误：

checking for %zd printf() format support... configure: error: cannot run test program while cross compiling See `config.log' for more details. [root@MontaVista Python-2.5.1]#

 

我开始寻找原因。在“./configure”文件中我发现如下代码段：

if test "$cross_compiling" = yes; then   { { echo "$as_me:$LINENO: error: catttnnot run test program while cross compiling See /`config.log' for more details." >&5 echo "$as_me: error: cannot run test program while cross compiling See /`config.log' for more details." >&2;}    { (exit 1); exit 1; }; } else

 

这一段代码段的意思很明显，就是如果“$cross_compiling”=yes”，就要执行“exit 1”。也就是说对于交叉编译，肯定是做不下去了。这是怎么回事呢？

我想来想去，觉得先把这段代码删除试试。于是就变成这样：

echo "$as_me:$LINENO: checking for %zd printf() format support" >&5 echo $ECHO_N "checking for %zd printf() format support... $ECHO_C" >&6 if test "$cross_compiling" = yes; then   { { echo "$as_me:$LINENO: error: catttnnot run test program while cross compiling See /`config.log' for more details." >&5 echo "$as_me: error: cannot run test program while cross compiling See /`config.log' for more details." >&2;}    }

就是直接把“(exit 1); exit 1; };”删除了。注意这里的“;”都不要留下来。

 

然后重新执行ppc的交叉编译前奏，跳过了那一步之后，竟然通过了！于是，我又开始执行“make –s”，中间出现了很多warning，部分摘录如下：

./Modules/_codecsmodule.c:555: warning: dereferencing type-punned pointer will break strict-aliasing rules ./Modules/zipimport.c: In function `initzipimport': ./Modules/zipimport.c:1181: warning: dereferencing type-punned pointer will break strict-aliasing rules ./Modules/xxsubtype.c: In function `initxxsubtype': ./Modules/xxsubtype.c:292: warning: dereferencing type-punned pointer will break strict-aliasing rules ./Modules/xxsubtype.c:297: warning: dereferencing type-punned pointer will break strict-aliasing rules libpython2.5.a(posixmodule.o)(.text+0x51e4): In function `posix_tmpnam': ./Modules/posixmodule.c:6850: warning: the use of `tmpnam_r' is dangerous, better use `mkstemp' libpython2.5.a(posixmodule.o)(.text+0x50f4): In function `posix_tempnam': ./Modules/posixmodule.c:6805: warning: the use of `tempnam' is dangerous, better use `mkstemp'

不过一直都没有中断，直到最后，出现了“./python: cannot execute binary file”，退出了编译。

/bin/sh: line 1: ./python: cannot execute binary file make: *** [sharedmods] Error 126 [root@MontaVista Python-2.5.1]# ll

 

一开始我以为“真的”出错了，但是立刻我就想起来，我们编译出来的最终python可执行程序是在PowerPC/linux上才能跑的，现在在x86/linux上，当然不能跑！于是我认为已经成功了！只要输出就好了！于是赶紧“ll”以下当前目录，果然，看到了“python”和“libpython2.5.a”（就这两个输出是同一个时间的）两个最新的文件！！！：

[jiangsy@MontaVista Python-2.5.1]$ ll *python* -rw-r--r--    1 root     root      4814512 Sep 27 19:20 libpython2.5.a -rwxr-xr-x    1 root     root      3014140 Sep 27 19:20 python

 

我把着两个文件TFTP bin模式上传到ICM3G上面，使用“bash-2.05a# chmod a+x python”修改了属性，然后尝试运行。天哪！成功了！！！！！！

bash-2.05a# ./python Could not find platform independent libraries Could not find platform dependent libraries Consider setting $PYTHONHOME to [:] 'import site' failed; use -v for traceback Python 2.5.1 (r251:54863, Sep 27 2007, 19:20:03) [GCC 3.4.1 (MontaVista 3.4.1-2.0.16.0501116 2005-07-21)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> a=2 >>> a 2 >>> a=3 >>> a 3 >>> >>> >>>

 

此时此刻，我能说什么呢？我太激动了。程序员的要求，原来就是如此而已啊！如果编译失败，今晚肯定很难睡着觉了。可是现在，竟然成功了，可是我还是很难睡着觉吧？这几天一直失眠，这是一个原因；另一个原因，我太激动了！我还能睡得着吗？后面还会有多少问题呢？而且，我为之奋斗了一个下午，加上黄昏到现在，我总算有个成果了。想想工作近七年，有多少天是面对失败而失眠！

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