Hello Andreas, Thank you for the reply. I have made some progress since my initial post, I have found that part of the problem is that I am using gcc 4.2 and the various #defines for atomics assume that 4.2 will have the appropriate support. The compiler expects that `__sync_add_and_fetch_4' will be provided. I've found there is some assembler provided with the compiler which gives a 'atomic_exchange_and_add' macro which I've had working correctly in a demo programme, but I haven't yet got it integrated with boost, though that would be a nice long-term solution. Back to the problem though. I've tried a clean build with BOOST_ASIO_DISABLE_FENCED_BLOCK but I'm still getting the same problem. I've attached the build output below. Here are the steps I took to make the clean build: 1.    unzip boost_1_48_0.zip 2.    mkdir boost-binary 3.    set and export     BOOST_BUILD_ROOT=/home/jayne/boost-stb/boost_1_48_0     export BOOST_BUILD_ROOT     BOOST_BIN_ROOT=$BOOST_BUILD_ROOT/boost-binary     export BOOST_BIN_ROOT 4.    ./bootstrap.sh 5.    Edit the resulting project-config.jam file (which has been generated for the host x86 system)     using gcc : mipsel : mipsel-linux-g++ ; and     option.set prefix : /opt/brcm/stblinux-2.6.31 ;     option.set exec-prefix : /opt/brcm/stblinux-2.6.31 ;     option.set libdir : /opt/brcm/stblinux-2.6.31/lib ;     option.set includedir : /opt/brcm/stblinux-2.6.31/include/linux ; 6.    Edit tools/build/v2/tools/gcc.jam to remove ‘-pendantic’ option (otherwise the string library assembler will not compile) 7.    Run  ./b2 cxxflags=-DBOOST_ASIO_DISABLE_FENCED_BLOCK --without-python --without-mpi 8.    Run ./b2 threading=multi variant=release link=shared toolset=gcc --build-dir=$BOOST_BIN_ROOT --prefix=/tmp/boost --without-python --without-mpi install While compiling in step 7, a typical compiler line is: "mipsel-linux-g++"  -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -DBOOST_ASIO_DISABLE_FENCED_BLOCK -Wextra -Wno-long-long -pedantic -DBOOST_ALL_DYN_LINK=1 -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DNDEBUG  -I"." -c -o "bin.v2/libs/chrono/build/gcc-mipsel/release/threading-multi/process_cpu_clocks.o" "libs/chrono/src/process_cpu_clocks.cpp" This is the output from build: /opt/bcmtools/bin/mipsel-linux-g++  -O2 -I/tmp/boost/include echo_server.o network_utilities.o sha1.o base64.o md5.o uri.o hybi_header.o data.o atomic.o -o echo_server -L/tmp/boost/lib -lboost_regex -lboost_date_time -lboost_program_options -lboost_system  -lboost_thread echo_server.o: In function `boost::asio::detail::wait_handler::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail12wait_handlerINS_3_bi6bind_tIvNS_4_mfi3mf0IvN11websocketpp4role6serverINS7_8endpointIS9_NS7_6socket5plainENS7_3log6loggerEEEEEEENS3_5list1INS3_5valueIPSG_EEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationERKNS_6system10error_codeEj+0x94): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::wait_handler::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail12wait_handlerINS_3_bi6bind_tIvNS_4_mfi3mf1IvN11websocketpp10connectionINS7_8endpointINS7_4role6serverENS7_6socket5plainENS7_3log6loggerEEENSB_ISG_E10connectionENSD_ISG_E10connectionEEERKNS_6system10error_codeEEENS3_5list2INS3_5valueINS_10shared_ptrISL_EEEEPFNS_3argILi1EEEvEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationESP_j+0xd4): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_accept_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail25reactive_socket_accept_opINS0_12basic_socketINS0_2ip3tcpENS0_21stream_socket_serviceIS5_EEEES5_NS_3_bi6bind_tIvNS_4_mfi3mf2IvN11websocketpp4role6serverINSD_8endpointISF_NSD_6socket5plainENSD_3log6loggerEEEEENS_10shared_ptrINSD_10connectionISL_NSM_10connectionENSI_ISL_E10connectionEEEEERKNS_6system10error_codeEEENS9_5list3INS9_5valueIPSM_EENS10_IST_EEPFNS_3argILi1EEEvEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationESX_j+0xdc): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_service_base::start_op(boost::asio::detail::reactive_socket_service_base::base_implementation_type&, int, boost::asio::detail::reactor_op*, bool, bool)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x1b0): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x2b4): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x2ec): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x3cc): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x548): undefined reference to `__sync_fetch_and_add_4' echo_server.o:echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x65c): more undefined references to `__sync_fetch_and_add_4' follow echo_server.o: In function `boost::asio::detail::reactive_socket_send_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_send_opINS1_17consuming_buffersINS0_12const_bufferEN11websocketpp19shared_const_bufferEEENS1_8write_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceISB_EEEES6_NS1_14transfer_all_tENS_3_bi6bind_tIvNS_4_mfi3mf1IvNS5_4role6serverINS5_8endpointISL_NS5_6socket5plainENS5_3log6loggerEEEE10connectionINS5_10connectionISR_NSS_10connectionENSO_ISR_E10connectionEEEEERKNS_6system10error_codeEEENSG_5list2INSG_5valueINS_10shared_ptrISY_EEEEPFNS_3argILi1EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationES13_j+0x1a8): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_send_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_send_opINS1_17consuming_buffersINS0_12const_bufferESt6vectorIS4_SaIS4_EEEENS1_8write_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceISC_EEEES7_NS1_14transfer_all_tENS_3_bi6bind_tIvNS_4_mfi3mf1IvN11websocketpp10connectionINSL_8endpointINSL_4role6serverENSL_6socket5plainENSL_3log6loggerEEENSP_ISU_E10connectionENSR_ISU_E10connectionEEERKNS_6system10error_codeEEENSH_5list2INSH_5valueINS_10shared_ptrISZ_EEEEPFNS_3argILi1EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationES13_j+0x208): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::epoll_reactor::descriptor_state::perform_io(unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state10perform_ioEj+0x244): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state10perform_ioEj+0x324): undefined reference to `__sync_fetch_and_add_4' echo_server.o: In function `boost::asio::detail::epoll_reactor::descriptor_state::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationERKNS_6system10error_codeEj+0x21c): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationERKNS_6system10error_codeEj+0x340): undefined reference to `__sync_fetch_and_add_4' echo_server.o: In function `boost::asio::detail::reactive_socket_recv_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_recv_opINS0_17mutable_buffers_1ENS1_26read_until_delim_string_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceIS7_EEEESaIcENS_3_bi6bind_tIvNS_4_mfi3mf2IvN11websocketpp4role6serverINSG_8endpointISI_NSG_6socket5plainENSG_3log6loggerEEEE10connectionINSG_10connectionISO_NSP_10connectionENSL_ISO_E10connectionEEEEERKNS_6system10error_codeEjEENSC_5list3INSC_5valueINS_10shared_ptrISV_EEEEPFNS_3argILi1EEEvEPFNS17_ILi2EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationES10_j+0x13c): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_recv_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_recv_opINS0_17mutable_buffers_1ENS1_17read_streambuf_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceIS7_EEEESaIcENS1_19transfer_at_least_tENS_3_bi6bind_tIvNS_4_mfi3mf1IvN11websocketpp10connectionINSH_8endpointINSH_4role6serverENSH_6socket5plainENSH_3log6loggerEEENSL_ISQ_E10connectionENSN_ISQ_E10connectionEEERKNS_6system10error_codeEEENSD_5list2INSD_5valueINS_10shared_ptrISV_EEEEPFNS_3argILi1EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationESZ_j+0x104): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `websocketpp::message::intrusive_ptr_release(websocketpp::message::data const*)': echo_server.cpp:(.gnu.linkonce.t._ZN11websocketpp7message21intrusive_ptr_releaseEPKNS0_4dataE+0x34): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN11websocketpp7message21intrusive_ptr_releaseEPKNS0_4dataE+0x114): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN11websocketpp7message21intrusive_ptr_releaseEPKNS0_4dataE+0x244): undefined reference to `__sync_fetch_and_add_4' echo_server.o: In function `std::deque::_M_push_back_aux(boost::intrusive_ptr const">On Fri 17/02/12 07:01 , "Andreas Wehrmann" a.wehrmann@centersystems.com sent: On 02/16/2012 10:06 AM, Jayne wrote:

Hello,

I'm trying to build Boost 1.48.0 for use with the WebSockets++ library on a MIPS based embedded Linux board.

My build machine reports itself as: Linux version

2.6.40.4-5.fc15.x86_64

(mockbuild@x86-10.phx2.fedoraproject.org) (gcc version 4.6.0 20110603 (Red Hat 4.6.0-10) (GCC) ) #1 SMP Tue Aug 30 14:38:32 UTC 2011

My cross-compiler version is: mipsel-linux-g++ (GCC) 4.2.0 20070124 (prerelease) - BRCM 11ts-20090508. I don't have any control over this as its provided by the chip manufacturer.

I can build Boost without any reported errors and can link to and use most of the libraries without any problems. However, when WebSockets tries to link to the Boost::asio library I get link errors like this:

(.gnu.linkonce.t._ZNSt5dequeIN5boost13intrusive_ptrIN11websocketpp7message4dataEEESaIS5_EE16_M_push_back_auxERKS5_+0x30):

undefined reference to `__sync_add_and_fetch_4'

(.gnu.linkonce.t._ZNSt5dequeIN5boost13intrusive_ptrIN11websocketpp7message4dataEEESaIS5_EE16_M_push_back_auxERKS5_+0x80):

undefined reference to `__sync_add_and_fetch_4'

(.gnu.linkonce.t._ZN11websocketpp9processor4hybiINS_10connectionINS_8endpointINS_4role6serverENS_6socket5plainENS_3log6loggerEEENS5_ISA_E10connectionENS7_ISA_E10connectionEEEE19prepare_close_frameEN5boost13intrusive_ptrINS_7message4dataEEENS_5close6status5valueERKSs+0xc8):

more undefined references to `__sync_add_and_fetch_4' follow

I've done enough research to find this has been a problem in the past with ARM chips and is to do with atomic transactions not being implemented by gcc for the target machine. I've tried the suggested fixes for ARM which were to build with either BOOST_SP_DISABLE_THREADS or BOOST_SP_USE_PTHREADS but that didn't help with my MIPS environment.

Can anyone make any suggestions as to what I could try next?

thanks,

Jayne.

Try this #define: BOOST_ASIO_DISABLE_FENCED_BLOCK -- Dipl.-Ing. (FH) Andreas Wehrmann Software Development -------------------------------------------------------------- Center Communication Systems GmbH Sitz in Wien FN 796 88p, Firmenbuchgericht Wien http://www.centersystems.com [1]">www.centersystems.com Tel.: +43 (0) 190 199 - 3616 Mobile: +43 (0) 664 884 75916 Fax: +43 (0) 190 199 - 2110 E-Mail: a.wehrmann@centersystems.com _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users [2]">http://lists.boost.org/mailman/listinfo.cgi/boost-users Links: ------ [1] http://www.centersystems.com [2] http://lists.boost.org/mailman/listinfo.cgi/boost-users