【发布时间】：2014-06-10 12:52:03
【问题描述】：
我的源码树是
cpp
├── bin
├── CMakeLists.txt
├── src
├── headers
├── Makefile
├── TestConfig.h
├── TestConfig.h.in
├── README.txt
├── third_party
├── x_build
└── xtoolchain.cmake
我正在使用crosstool-ng。
编辑： 附加信息（可能对其他人有所帮助）：我使用了 http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/ 的引用通过 QEMU 引导 RPI（重要的是，将 img 文件的大小调整为 8GB）。
qemu-img resize 2014-01-07-wheezy-raspbian.img +6G
sudo fdisk /dev/mmcblk0
- use "parted" or 'd' options to delete the 2nd partition and then recreate it but with a larger size. (don't worry, the data will remain). 1st partition is vfat.
- reboot to activate the partition changes.
- use "sudo resize2fs /dev/mmclk0p2" (or /dev/sda2 if symlink set in udev rules) to enlarge the root file system.
- use e2fsck -f /dev/mmcblk0p2 to perform a file system check.
使用apt-get 安装了所有lib<package>-dev 和其他库。然后关闭 QEMU
mkdir -p /tmp/rasp
sudo mount /home/test/raspberrypi/2014-01-07-wheezy-raspbian.img /tmp/rasp/ -o offset=$((122880*512))
cd $HOME/raspberrypi
sudo cp -ar /tmp/rasp ./rootfs
sudo chown -R $USER:$USER rootfs/home/pi
cd $HOME/raspberrypi/rootfs
# also small hack around: error "Never use <bits/predefs.h> directly; include <stdc-predef.h> instead."
sudo cp /home/test/raspberrypi/rootfs/usr/include/features.h /home/test/raspberrypi/rootfs/usr/include/features.h-
sudo cp /home/test/local/x-tools/arm-unknown-linux-gnueabi/arm-unknown-linux-gnueabi/sysroot/usr/include/features.h /home/test/raspberrypi/rootfs/usr/include
sudo umount /tmp/rasp
我还设置了目标文件系统/home/test/raspberrypi/rootfs（这包含了已经安装的交叉编译所需的所有库）
xtoolchain.cmake 如下所示
# ========================= CROSS COMPILATION INITIALIZATION BEGIN =======================
# this one is important
SET(CMAKE_SYSTEM_NAME Linux)
#this one not so much
SET(CMAKE_SYSTEM_VERSION 1)
# specify the cross compiler
SET(CMAKE_C_COMPILER
$ENV{HOME}/local/x-tools/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-gcc)
SET(CMAKE_CXX_COMPILER
$ENV{HOME}/local/x-tools/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-g++)
# where is the target environment
#SET(CMAKE_FIND_ROOT_PATH
#/home/test/local/x-tools/arm-unknown-linux-gnueabi /home/test/raspberrypi/rootfs)
SET(CMAKE_FIND_ROOT_PATH $ENV{HOME}/raspberrypi/rootfs)
# search for programs in the build host directories
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
# for libraries and headers in the target directories
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
#include_directories ("/home/test/local/raspidev/include")
# ========================= CROSS COMPILATION INITIALIZATION END =========================
src 目录中的 CMakeLists.txt（这是在父目录中的 CMakeLists.txt 的补充，您可以从文件结构中看到）部分看起来像
cmake_minimum_required(VERSION 2.8)
...
...
...
#Change 1 to 0 to disable logging
add_definitions(-DENABLE_LOG=1)
set(CMAKE_PREFIX_PATH $ENV{HOME}/raspberrypi/rootfs/)
set(CMAKE_LIBRARY_PATH $ENV{HOME}/raspberrypi/rootfs/lib:$ENV{HOME}/raspberrypi/rootfs/usr/lib:$ENV{HOME}/raspberrypi/rootfs/usr/local/lib)
set(CMAKE_MODULE_PATH $ENV{HOME}/raspberrypi/rootfs/usr/share/cmake-2.8/Modules)
#rdynamic is for stack unwinding on crash
set(CMAKE_CXX_FLAGS "-W -O3 -g -Wall -std=c++0x -rdynamic -D_AIBTRACE ${CMAKE_CXX_FLAGS}")
set_target_properties(${TARGET} PROPERTIES COMPILE_FLAGS ${CMAKE_CXX_FLAGS})
include_directories ("${PROJECT_SOURCE_DIR}/headers")
#add_subdirectory (headers)
...
...
...
# ======================== SQLITE3 =================================
pkg_check_modules(SQLITE3 REQUIRED sqlite3)
include_directories(${SQLITE3_INCLUDE_DIRS})
...
... (...And other libraries)
我在x_build 目录中进行了源外构建。如下
cmake -DCMAKE_TOOLCHAIN_FILE=/home/test/xcompile/cpp/xtoolchain.cmake ../
奇怪的是，它似乎链接的是宿主库而不是目标库。 make VERBOSE=1 显示这个
它为所有库引发链接器错误（这些库肯定存在于目标系统rootfs）
/home/test/local/x-tools/arm-unknown-linux-gnueabi/lib/gcc/arm-unknown-linux-gnueabi/4.7.3/../../../../arm-unknown-linux-gnueabi/bin/ld: cannot find -lgmodule-2.0
/home/test/local/x-tools/arm-unknown-linux-gnueabi/lib/gcc/arm-unknown-linux-gnueabi/4.7.3/../../../../arm-unknown-linux-gnueabi/bin/ld: cannot find -lgthread-2.0
/home/test/local/x-tools/arm-unknown-linux-gnueabi/lib/gcc/arm-unknown-linux-gnueabi/4.7.3/../../../../arm-unknown-linux-gnueabi/bin/ld: cannot find -lxml2
/home/test/local/x-tools/arm-unknown-linux-gnueabi/lib/gcc/arm-unknown-linux-gnueabi/4.7.3/../../../../arm-unknown-linux-gnueabi/bin/ld: cannot find -lglib-2.0
/home/test/local/x-tools/arm-unknown-linux-gnueabi/lib/gcc/arm-unknown-linux-gnueabi/4.7.3/../../../../arm-unknown-linux-gnueabi/bin/ld: cannot find -lsqlite3
/home/test/local/x-tools/arm-unknown-linux-gnueabi/lib/gcc/arm-unknown-linux-gnueabi/4.7.3/../../../../arm-unknown-linux-gnueabi/bin/ld: cannot find -ldbus-1
collect2: error: ld returned 1 exit status
我有点迷茫。
编辑：
根据这里的要求，还有一些来自CMakeLists.txt的东西
set (SOURCES
file1.cc
file2.cc
main.cc
)
# Similarly, why not concise files grouping that will be reused ;)?
set (COMMONS_LIBS
${OpenCV_LIBS}
pthread
${GLIBMM_LIBRARIES}
${GTKMM_LIBRARIES}
#${GSTMM_LIBRARIES}
${GSTREAMER_LIBRARIES}
${SQLITE3_LIBRARIES}
#${DBUS_GLIB_LIBRARY}
${DBUS_LIBRARIES}
${DBUS_GLIB_LIBRARIES}
${OPENSSL_LIBRARIES}
)
add_executable (
${EXE_DAEMON}
${SOURCES}
)
target_link_libraries(
${EXE_DAEMON}
$COMMONS_LIBS}
)
install (TARGETS
${EXE_DAEMON}
DESTINATION bin)
【问题讨论】：
-
你能告诉我们完整的
ld命令吗？ -
@Peter 我的编辑有帮助吗？
-
你能在这里粘贴完整链接命令（创建上面显示的错误的命令），而不是创建它的 CMakeLists.txt 吗？
-
@Peter，找到解决方案，查看答案。我显然错过了一些路径。除了 cmake 博客页面上的跨工具链设置列表之外，这些似乎是必要的。
-
请不要在标题中添加“[已解决]”。表明您的问题已解决的方法是接受答案。 （是的，接受你自己的答案是完全可以接受的。）
标签： c cmake raspberry-pi cross-compiling embedded-linux