libwebsocket库的交叉编译和使用方法

./config no-asm shared no-async --prefix=/opt/lib/openssl-1.1.1g --cross-compile-prefix=/opt/toolchains/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf-
make -j8
make install
复制

./configure --prefix=/opt/lib/wolfssl-3.13.0 --host=arm-linux --enable-openssh --enable-static --disable-shared
CC=/opt/toolchains/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc
make
make install
复制

git clone https://github.com/warmcat/libwebsockets.git
复制

vim CMakeLists.txt
# 设置交叉编译 -----------------------------------------------
# CMAKE_SYSTEM_NAME:指定目标机所在的操作系统名称,只有当该变量被设置了，CMake才认为此时正值交叉编译
# CMAKE_FIND_ROOT_PATH:代表一系列的相关文件夹路径的根路径的变更，所有的Find_***.cmake脚本首先会在这个路径的usr/lib，lib目录下找，然后才会去系统的目录下可>以指定多个路径
# CMAKE_FIND_ROOT_PATH_MODE_PROGRAM:有三种取值:NEVER,ONLY,BOTH  ，这边选NEVER表示不在当前机器的系统目录下查找，而是去宿主机查找
# CMAKE_FIND_ROOT_PATH_MODE_LIBRARY:选ONLY表示依赖库只在交叉编译环境中找
# CMAKE_FIND_ROOT_PATH_MODE_INCLUDE:表示依赖的头文件只在交叉编译环境中找
# CMAKE_C_COMPILER CMAKE_CXX_COMPILE:指定交叉编译链gcc和g++


SET(CMAKE_SYSTEM_NAME Linux)
SET(CMAKE_FIND_ROOT_PATH "/opt/toolchains/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/")
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
SET(CMAKE_C_COMPILER "/opt/toolchains/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc")
SET(CMAKE_CXX_COMPILE "/opt/toolchains/gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf-g++")


#告诉编译器产生与位置无关代码(Position-Independent Code)，使用相对地址
add_compile_options(-fPIC)


#关闭警告当做错误
option(DISABLE_WERROR "Avoid treating compiler warnings as fatal errors" ON


#
# TLS library options... all except mbedTLS are basically OpenSSL variants.
#
option(LWS_WITH_SSL "Include SSL support (defaults to OpenSSL or similar, mbedTLS if LWS_WITH_MBEDTLS is set)" ON)
option(LWS_WITH_MBEDTLS "Use mbedTLS (>=2.0) replacement for OpenSSL. When setting this, you also may need to specify LWS_MBEDTLS_LIBRARIES and LWS_MBEDTLS_INCLUDE_DIRS" OFF)
option(LWS_WITH_BORINGSSL "Use BoringSSL replacement for OpenSSL" OFF)
option(LWS_WITH_CYASSL "Use CyaSSL replacement for OpenSSL. When setting this, you also need to specify LWS_CYASSL_LIBRARIES and LWS_CYASSL_INCLUDE_DIRS" OFF)
option(LWS_WITH_WOLFSSL "Use wolfSSL replacement for OpenSSL. When setting this, you also need to specify LWS_WOLFSSL_LIBRARIES and LWS_WOLFSSL_INCLUDE_DIRS" OFF)
option(LWS_SSL_CLIENT_USE_OS_CA_CERTS "SSL support should make use of the OS-installed CA root certs" OFF)
option(LWS_TLS_LOG_PLAINTEXT_RX "For debugging log the received plaintext as soon as decrypted" OFF)
option(LWS_TLS_LOG_PLAINTEXT_TX "For debugging log the transmitted plaintext just before encryption" OFF)
option(LWS_WITH_TLS_SESSIONS "Enable persistent, resumable TLS sessions" ON)
option(LWS_WITH_TLS_JIT_TRUST "Enable dynamically computing which trusted TLS CA is needed to be instantiated" ON)
复制

mkdir build
cd build
# openssl
cmake ../ -DCMAKE_INSTALL_PREFIX=/opt/lib/libwebsockets/ -DLWS_OPENSSL_INCLUDE_DIRS="/opt/lib/openssl-1.1.1g/include/" -DLWS_OPENSSL_LIBRARIES="/opt/lib/openssl-1.1.1g/lib/libssl.so;/opt/lib/openssl-1.1.1g/lib/libcrypto.so"
# wolfssl


# 为了调试可以添加DEBUG编译选项，-DCMAKE_BUILD_TYPE=DEBUG / RELEASE
# 也可以设置 `-DLWS_LOGGING_BITFIELD_SET="LLL_INFO|LLL_DEBUG"`，这将即使在RELEASE模式下，也会导致内置这些日志级别的跟踪。
复制

sudo make
sudo make install
复制

#查看交叉编译结果是否是ARM架构
readelf -h XXX.a
file xxx.so
复制