Table of Contents
Compiling ima-carpc package
prepare maketools
./autogen.sh mkdir build cp build_script.sh build cd build; ./build_script.sh
carpcd: configure.ac
139 # Set -DUCLIBC_OWRT and put it in config.h.in 140 AM_CONDITIONAL([UCLIBC_OWRT], [test 1]) 141 AC_DEFINE([UCLIBC_OWRT],[1],[Compile on openwrt_uclibc]) 142 143 AM_CONDITIONAL([GPS_DEBUG], [test ]) 144 AC_DEFINE([GPS_DEBUG],[0],[Test with gpsd ver. < 2.5])
carpcd: src/Makefile.am
36 if UCLIBC_OWRT 37 AM_CPPFLAGS += -DUCLIBC_OWRT @OONET_CPPFLAGS@ @DAIUTIL_CPPFLAGS@ @YAJL_CPPFLAGS@ \ 38 @LIBPHIDGET_CPPFLAGS@ \ 39 $(GPSD_CPPFLAGS) 40 endif
IMA carpcd packaging
We are using Attitude Adjustment.
12.09 branch (Attitude Adjustment)
Main repository
git clone git://git.openwrt.org/12.09/openwrt.git
Packages feed
git clone git://git.openwrt.org/12.09/packages.git
Check out certain revision
git commits are tagged with SVN ids.
git log --grep=<svn id>
Git create own branch td_xxxx
Usefulness
[dang@localhost openwrt]$ find feeds -name *gdb* feeds/packages.tmp/info/.packageinfo-libs_gdbm feeds/packages/libs/gdbm feeds/packages/net/dsniff/patches/003-gdbm.patch [dang@localhost openwrt]$ find package/ -name *gdb*
Fix Other packages
carpcd
- libgpsmm.h not available by default so fix libgps.
vim feeds/packages/net/gpsd/Makefile
95 SCONS_OPTIONS += \ 96 dbus_export=no \ 97 tsip=no \ 98 fv18=no \ 99 tripmate=no \ 100 earthmate=no \ 101 itrax=no \ 102 navcom=no \ 103 ubx=no \ 104 evermore=no \ 105 ntrip=no \ 106 libgpsmm=yes \ <---------- enable it! 107 libQgpsmm=no \ 108 bluez=no \ 109 strip=no \ ... 114 define Build/InstallDev 115 $(INSTALL_DIR) $(1)/usr/include 116 $(CP) $(PKG_INSTALL_DIR)/usr/include/gps.h $(1)/usr/include/ 117 $(CP) $(PKG_INSTALL_DIR)/usr/include/libgpsmm.h $(1)/usr/include/ <------ make libgpsmm.h available after installation 118 $(INSTALL_DIR) $(1)/usr/lib 119 $(CP) $(PKG_INSTALL_DIR)/usr/lib/libgps*.so* $(1)/usr/lib/ 120 $(INSTALL_DIR) $(1)/usr/lib/pkgconfig 121 $(CP) \ 122 $(PKG_INSTALL_DIR)/usr/lib/pkgconfig/libgps*.pc \ 123 $(1)/usr/lib/pkgconfig/ 124 endef
- libstdcpp is also not available. <code> 38 define Package/gpsd 39 $(call Package/gpsd/Default) 40 SECTION:=net 41 CATEGORY:=Network 42 DEPENDS+= +libgps +libgpsd +libstdcpp ←—- add libstdcpp 43 TITLE:=An interface daemon for GPS receivers 44 endef … 69 define Package/libgps 70 $(call Package/gpsd/Default) 71 SECTION:=libs 72 CATEGORY:=Libraries 73 DEPENDS+= +libcap +libstdcpp ←—- add libstdcpp 74 TITLE:=C service library for communicating with the GPS daemon 75 endef
</code>
webcam motion ffmpeg
- ffmpeg needs
- ffprobe
- ffserver
NFC
Libs:
- libnfc & libllcp
Demo code:
TODO:
- see if kernel module for nfc and llcp work.
- how kernel detect nfc usb device?.
NFC Spec
TNF
Empty 0x00 NFC Forum well-known type [NFC RTD] 0x01 Media-type as defined in RFC 2046 [RFC 2046] 0x02 Absolute URI as defined in RFC 3986 [RFC 3986] 0x03 NFC Forum external type [NFC RTD] 0x04 Unknown 0x05 Unchanged (see section 2.3.3) 0x06 Reserved 0x07
Sample message:
SnepLength=60 N DEF RECORDS: 2 Record0 0x7f0550000990 Record1 0x7f0550000b70 Version: 10 MessageCode: 2 Snep Length: 60 NDefRecord 0: >> Ndef HeaderFlags: 82 >>>> TNF: 2 <------------ >>>> IL: 0 >>>> SR: 0 >>>> CF: 0 >>>> ME: 0 >>>> MB: 1 >> Type: application/com.example.nfc_test >> Payload length: 11 >> Payload: test1 test2 test3 NDefRecord 1: >> Ndef HeaderFlags: 44 >>>> TNF: 4 >>>> IL: 0 >>>> SR: 0 >>>> CF: 0 >>>> ME: 1 >>>> MB: 0 >> Type: android.com.pkg >> Payload length: 14 >> Payload: com.example.nfc_test
NFC device used
-
- PN532 NFC Breakout Board
NFCClient dev
[dang@localhost build]$ sudo ./src/nfcclient ***** start ***** libnfc-llcp.llc.link service 0x16ae6c0 bound to SAP 1 libnfc-llcp.llc.link service 0x16ae5f0 bound to SAP 32 mac_link_activate_as_initiator libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) Attempting to activate LLCP Link as initiator libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) nfc_initiator_init() succeeded libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) nfc_initiator_poll_dep_target() succeeded libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) LLCP Link activated (initiator) libnfc-llcp.llc.link llc_link_configure (0x16adf00, (nil), 0) libnfc-llcp.llc.link mq_open (/libnfc-llcp-2548-0x16adf00-up) libnfc-llcp.llc.link mq_open (/libnfc-llcp-2548-0x16adf00-down) libnfc-llcp.llc.link LLC Link started successfully libnfc-llcp.llc.llc (0x7f855525a700) Link activated libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ llc_connection_wait() libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) libnfc-llcp.mac.link Received 2 bytes (Requested 8192, buffer size 2) libnfc-llcp.mac.link Received 2 PDU bytes libnfc-llcp.llc.llc (0x7f855525a700) Received 2 byteslibnfc-llcp.mac.link Sending 19 bytes libnfc-llcp.mac.link Sending 19 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) libnfc-llcp.llc.llc (0x7f855525a700) Symmetry PDU libnfc-llcp.llc.llc (0x7f855525a700) Read -1 bytes from service 32 libnfc-llcp.llc.llc (0x7f855525a700) mq_send+ libnfc-llcp.llc.llc (0x7f855525a700) Nothing to send libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ libnfc-llcp.mac.link Received 2 bytes (Requested 8192, buffer size 2) libnfc-llcp.mac.link Received 2 PDU bytes libnfc-llcp.llc.llc (0x7f855525a700) Received 2 bytes libnfc-llcp.mac.link libnfc-llcp.llc.llc (0x7f855525a700) Symmetry PDU Sending 2 bytes libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) libnfc-llcp.llc.llc (0x7f855525a700) Read -1 bytes from service 32 libnfc-llcp.llc.llc (0x7f855525a700) mq_send+ libnfc-llcp.llc.llc (0x7f855525a700) Nothing to send libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ libnfc-llcp.mac.link Received 2 bytes (Requested 8192, buffer size 2) libnfc-llcp.mac.link Received 2 PDU bytes libnfc-llcp.llc.llc (0x7f855525a700) Received 2 bytes libnfc-llcp.llc.llc (0x7f855525a700) Connection Complete PDU libnfc-llcp.llc.llc (0x7f855525a700) Read -1 bytes from service 32 service start libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) Status is now connected libnfc-llcp.llc.llc (0x7f855525a700) mq_send+ libnfc-llcp.llc.llc (0x7f855525a700) Nothing to send libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ setMessageBegin setMessageEnd NdefRecord::encode() NdefRecord::encode() SnepLength=64 N DEF RECORDS: 2 Record0 0x7f8548000990 Record1 0x7f8548000b70 Version: 10 MessageCode: 2 Snep Length: 64 NDefRecord 0: >> Ndef HeaderFlags: 82 >>>> TNF: 2 >>>> IL: 0 >>>> SR: 0 >>>> CF: 0 >>>> ME: 0 >>>> MB: 1 >> Type: application/com.example.android.beam >> Payload length: 11 >> Payload: test1 test2 test3 NDefRecord 1: >> Ndef HeaderFlags: 44 >>>> TNF: 4 >>>> IL: 0 >>>> SR: 0 >>>> CF: 0 >>>> ME: 1 >>>> MB: 0 >> Type: android.com.pkg >> Payload length: 14 >> Payload: com.example.nfc_test Message: 10 2 0 0 0 64 82 24 0 0 0 11 61 70 70 6c 69 63 61 74 69 6f 6e 2f 63 6f 6d 2e 65 78 61 6d 70 6c 65 2e 61 6e 64 72 6f 69 64 2e 62 65 61 6d 74 65 73 74 31 20 74 65 73 74 32 20 74 65 73 74 33 44 f 0 0 0 14 61 6e 64 72 6f 69 64 2e 63 6f 6d 2e 70 6b 67 63 6f 6d 2e 65 78 61 6d 70 6c 65 2e 6e 66 63 5f 74 65 73 74 Encoded message: d�$application/com.example.android.beamtest1 test2 test3Dandroid.com.pkgcom.example.nfc_test libnfc-llcp.mac.link Received 2 bytes (Requested 8192, buffer size 2) libnfc-llcp.mac.link Received 2 PDU bytes libnfc-llcp.llc.llc (0x7f855525a700) Received 2 bytes libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) libnfc-llcp.llc.llc (0x7f855525a700) Symmetry PDU libnfc-llcp.llc.llc (0x7f855525a700) Read 109 bytes from service 32 libnfc-llcp.llc.llc (0x7f855525a700) mq_send+ libnfc-llcp.llc.llc (0x7f855525a700) Sent 109 bytes libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ libnfc-llcp.mac.link Received 2 bytes (Requested 8192, buffer size 2) libnfc-llcp.mac.link Received 2 PDU bytes libnfc-llcp.mac.link Sending 109 bytes libnfc-llcp.mac.link Sending 109 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) libnfc-llcp.llc.llc (0x7f855525a700) Received 2 bytes libnfc-llcp.llc.llc (0x7f855525a700) Symmetry PDU libnfc-llcp.llc.llc (0x7f855525a700) Read -1 bytes from service 32 libnfc-llcp.llc.llc (0x7f855525a700) mq_send+ libnfc-llcp.llc.llc (0x7f855525a700) Nothing to send libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ libnfc-llcp.mac.link Received 3 bytes (Requested 8192, buffer size 3) libnfc-llcp.mac.link Received 3 PDU bytes libnfc-llcp.llc.llc (0x7f855525a700) Received 3 bytes libnfc-llcp.mac.link libnfc-llcp.llc.llc Sending 2 bytes(0x7f855525a700) Receive Ready PDU libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) libnfc-llcp.llc.llc (0x7f855525a700) Read -1 bytes from service 32 libnfc-llcp.llc.llc (0x7f855525a700) mq_send+ libnfc-llcp.llc.llc (0x7f855525a700) Nothing to send libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ libnfc-llcp.mac.link Received 9 bytes (Requested 8192, buffer size 9) libnfc-llcp.mac.link Received 9 PDU bytes libnfc-llcp.llc.llc (0x7f855525a700) Received 9 bytes NOT NULL 10 81 00 00 00 00 00 00 6a 00 00 00 00 libnfc-llcp.mac.link 00 Sending 2 bytes libnfc-llcp.mac.link Sending 2 bytes libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote) 00 00 c0 0a 00 50 85 7f 00 00 85 00 00 00 00 00 00 libnfc-llcp.llc.llc (0x7f855525a700) Information PDU libnfc-llcp.llc.llc (0x7f855525a700) Send 9 bytes to service 32 Send NDEF message done. libnfc-llcp.llc.llc �(0x7f855525a700) Read -1 bytes from service 32 libnfc-llcp.llc.llc (0x7f855525a700) Send acknoledgment for received data libnfc-llcp.llc.llc (0x7f855525a700) mq_send+ libnfc-llcp.llc.llc (0x7f855525a700) Sent 3 bytes libnfc-llcp.llc.llc (0x7f855525a700) mq_receive+ libnfc-llcp.llc.connection Stopping Data Link Connection [32 -> 4] libnfc-llcp.llc.link Deactivating LLC Link libnfc-llcp.llc.link The LLC Link has an active MAC link libnfc-llcp.mac.link MAC Link deactivation requested (reason: 0) libnfc-llcp.mac.link Received 2 bytes (Requested 8192, buffer size 2) libnfc-llcp.mac.link MAC Link deactivated libnfc-llcp.llc.link Back to LLC Link deactivation libnfc-llcp.llc.link Stopping Data Link Connection [4205912 -> -1126872448] libnfc-llcp.llc.connection Stopping Data Link Connection [32 -> 4] libnfc-llcp.llc.connection Freeing Data Link Connection [32 -> 4] libnfc-llcp.llc.link Data Link Connection [4205912 -> -1126872448] stopped libnfc-llcp.llc.link LLC Link deactivated libnfc-llcp.llc.link Freeing service 32 libnfc-llcp.llc.link Freeing service 1 [dang@localhost build]$
NFC/nfcclient on openwrt
Device driver error: Unexpected PN53x reply!
Error
LIBNFC_LOG_LEVEL=3 nfc-list
root@imaopenwrt:~# nfc-list nfc-list uses libnfc 1.7.0 error libnfc.chip.pn53x Unexpected PN53x reply! pn53x_check_communication: Input / Output Error error libnfc.chip.pn53x Unexpected PN53x reply! nfc-list: ERROR: Unable to open NFC device: pn532_uart:/dev/ttyUSB0
Solution
Compile libnfc-1.7.1
New Source Location: https://bintray.com/nfc-tools/sources/libnfc
Link with libusb-1.0
compile libllcp and test
Device not found:
Resolution:
- configure device name in /etc/nfc/nfc.conf.
# Manually set default device (no default) # To set a default device, you must set both name and connstring for your device # Note: if autoscan is enabled, default device will be the first device available in device list. #device.name = "microBuilder.eu" #device.connstring = "pn532_uart:/dev/ttyUSB0" device.name = "imanfc" device.connstring = "pn532_uart:/dev/ttyUSB1"
- sudo nfc-list
examples/snep-server dbg out put
Segfault:
[pid 3366] <... ioctl resumed> , [0]) = 0
[pid 3365] <... munmap resumed> ) = 0
[pid 3366] write(4, "\0\0\377\4\374\324\216\0\0\236\0", 11 <unfinished ...>
[pid 3365] mprotect(0x7f90a4000000, 135168, PROT_READ|PROT_WRITE <unfinished ...>
[pid 3366] <... write resumed> ) = 11
[pid 3365] <... mprotect resumed> ) = 0
[pid 3366] select(5, [4], NULL, NULL, {0, 350000} <unfinished ...>
[pid 3365] mq_timedreceive(0, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 1024, 0, NULL) = -1 EBADF (Bad file descriptor)
[pid 3365] --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x55} ---
[pid 3366] +++ killed by SIGSEGV (core dumped) +++
[pid 3365] +++ killed by SIGSEGV (core dumped) +++
+++ killed by SIGSEGV (core dumped) +++
GDB
libnfc-llcp.mac.link Received 2 PDU bytes
libnfc-llcp.llc.llc libnfc-llcp.mac.link Sending 19 bytes(0x7ffff7abe700) Received 2 bytes
libnfc-llcp.llc.llc (0x7ffff7abe700) Symmetry PDU
libnfc-llcp.llc.llc (0x7ffff7abe700) Garbage-collecting Logical Data Link [32 -> 1]
libnfc-llcp.llc.connection Freeing Data Link Connection [32 -> 1]
libnfc-llcp.llc.llc (0x7ffff7abe700) Can' read from service 73 message queue
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7ffff7abe700 (LWP 929)]
llc_service_llc_thread (arg=0x611e40) at llc_service_llc.c:410
410 length = mq_receive(link->datagram_handlers[i]->llc_down, (char *) buffer, sizeof(buffer), NULL);
Missing separate debuginfos, use: debuginfo-install glibc-2.18-12.fc20.x86_64 libgcc-4.8.2-7.fc20.x86_64 libnfc-1.7.0-1.fc20.x86_64 libselinux-2.2.1-6.fc20.x86_64 libstdc++-4.8.2-7.fc20.x86_64 libusb-0.1.5-3.fc20.x86_64 libusbx-1.0.16-3.fc20.x86_64 pcre-8.33-4.fc20.x86_64 pcsc-lite-libs-1.8.10-1.fc20.x86_64 systemd-libs-208-9.fc20.x86_64 xz-libs-5.1.2-6alpha.fc20.x86_64
(gdb) l
405
406 ssize_t length = 0;
407 for (int i = 0; i <= MAX_LOGICAL_DATA_LINK; i++) {
408 if (link->datagram_handlers[i]) {
409 pthread_t thread = link->datagram_handlers[i]->thread;
410 length = mq_receive(link->datagram_handlers[i]->llc_down, (char *) buffer, sizeof(buffer), NULL);
411 if (length > 0)
412 break;
413 switch (errno) {
414 case EAGAIN:
(gdb) q
Solution
- Resolution: Increase MAXLOGICALDATALINK which is the upper-bounce of datagramhandlers[i]. in llcp.h:
55 //#define MAX_LOGICAL_DATA_LINK 8 56 #define MAX_LOGICAL_DATA_LINK 80
bug report
#4 thuydang...@gmail.com
Hi,
I seem to have problem with "receive" operation using both master- and socket-branch. My settings is Fedora 20 x86_64 <---> Android 4.4.2
I tested the "socket" branch and had ENOTSOCK from strace:
-----------
ioctl(7, FIONREAD <unfinished ...>
[pid 18493] select(9, [8], NULL, NULL, {0, 100000} <unfinished ...>
[pid 18492] <... ioctl resumed> , [2]) = 0
[pid 18492] recvfrom(7, "\0\0", 1024, 0, NULL, NULL) = 2
[pid 18492] mmap(NULL, 134217728, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = 0x7fd17761c000
[pid 18492] munmap(0x7fd17761c000, 10371072) = 0
[pid 18492] munmap(0x7fd17c000000, 56737792) = 0
[pid 18492] mprotect(0x7fd178000000, 135168, PROT_READ|PROT_WRITE) = 0
[pid 18492] recvfrom(0, 0x7fd18061a9e0, 1024, 0, 0, 0) = -1 ENOTSOCK (Socket operation on non-socket)
[pid 18492] --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x200000025} ---
[pid 18493] +++ killed by SIGSEGV (core dumped) +++
-------------
On the master branch I had EBADF (Bad file descriptor):
-----
[pid 19884] write(4, "\0\0\377\4\374\324\216\0\0\236\0", 11) = 11
[pid 19883] mq_timedreceive(0, <unfinished ...>
[pid 19884] select(5, [4], NULL, NULL, {0, 350000} <unfinished ...>
[pid 19883] <... mq_timedreceive resumed> "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 1024, 0, NULL) = -1 EBADF (Bad file descriptor)
[pid 19883] --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x55} ---
[pid 19883] +++ killed by SIGSEGV (core dumped) +++
-----
Today (moments ago) Delete comment
#5 thuydang...@gmail.com
Hi, during compilation there is also this warning, which seems to relate to the problem:
---
CC llc_link.lo
llc_link.c: In function 'llc_link_new':
llc_link.c:66:34: warning: iteration 8ul invokes undefined behavior [-Waggressive-loop-optimizations]
link->datagram_handlers[i] = NULL;
^
llc_link.c:64:5: note: containing loop
for (size_t i = 0; i < sizeof(link->available_services) / sizeof(*link->available_services); i++) {
^
CC llc_service.lo
---
- compiler agressive loop optimization: http://blog.regehr.org/archives/918
Disable aggressive loop optimization:
In configure.ac add:
CFLAGS="$CFLAGS -std=c99 -fno-aggressive-loop-optimizations"
A new option, <code>-fno-aggressive-loop-optimizations
, was added +can be disabled with
-Wno-aggressive-loop-optimizations
.</p>
<p>On ARM, a bug has been fixed in GCC's implementation of the AAPCS rules for the layout of vectors that could lead to wrong code being
</code>
Check mqueue
- m-queue limitations: http://kirkwylie.blogspot.de/2008/10/posix-message-queues-useful-but-limited.html
Ensure CONFIG_POSIX_MQUEUE is enabled
it's not in voyage for example
grep CONFIG_POSIX_MQUEUE /boot/config-3.10.11-xxx # CONFIG_POSIX_MQUEUE is not set
Other problems
GDB nfcclient:
sudo gdb ./src/nfcclient ... run [return]
error:
***** start *****
libnfc-llcp.llc.link service 0x6123c0 bound to SAP 1
libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) Attempting to activate LLCP Link as initiator
libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) nfc_initiator_init() succeeded
libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) nfc_initiator_poll_dep_target() succeeded
libnfc-llcp.mac.link (pn532_uart:/dev/ttyUSB1) LLCP Link activated (initiator)
libnfc-llcp.llc.link llc_link_configure (0x611e40, (nil), 0)
libnfc-llcp.llc.link mq_open (/libnfc-llcp-925-0x611e40-up)
libnfc-llcp.llc.link mq_open (/libnfc-llcp-925-0x611e40-down)
[New Thread 0x7ffff7abe700 (LWP 929)]
libnfc-llcp.llc.link LLC Link started successfully
libnfc-llcp.llc.llc (0x7ffff7abe700) Link activated
libnfc-llcp.llc.llc (0x7ffff7abe700) mq_receive+
[New Thread 0x7ffff72bd700 (LWP 930)]
libnfc-llcp.llc.link service 0x6122f0 bound to SAP 32
llc_connection_wait()
libnfc-llcp.mac.link Sending 2 bytes
libnfc-llcp.mac.link LTOs: 1000 ms (local), 100 ms (remote)
libnfc-llcp.mac.link Received 2 bytes (Requested 8192, buffer size 2)
libnfc-llcp.mac.link Received 2 PDU bytes
libnfc-llcp.llc.llc libnfc-llcp.mac.link Sending 19 bytes(0x7ffff7abe700) Received 2 bytes
libnfc-llcp.llc.llc (0x7ffff7abe700) Symmetry PDU
libnfc-llcp.llc.llc (0x7ffff7abe700) Garbage-collecting Logical Data Link [32 -> 1]
libnfc-llcp.llc.connection Freeing Data Link Connection [32 -> 1]
libnfc-llcp.llc.llc (0x7ffff7abe700) Can' read from service 73 message queue
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7ffff7abe700 (LWP 929)]
llc_service_llc_thread (arg=0x611e40) at llc_service_llc.c:410
410 length = mq_receive(link->datagram_handlers[i]->llc_down, (char *) buffer, sizeof(buffer), NULL);
Missing separate debuginfos, use: debuginfo-install glibc-2.18-12.fc20.x86_64 libgcc-4.8.2-7.fc20.x86_64 libnfc-1.7.0-1.fc20.x86_64 libselinux-2.2.1-6.fc20.x86_64 libstdc++-4.8.2-7.fc20.x86_64 libusb-0.1.5-3.fc20.x86_64 libusbx-1.0.16-3.fc20.x86_64 pcre-8.33-4.fc20.x86_64 pcsc-lite-libs-1.8.10-1.fc20.x86_64 systemd-libs-208-9.fc20.x86_64 xz-libs-5.1.2-6alpha.fc20.x86_64
(gdb) l
405
406 ssize_t length = 0;
407 for (int i = 0; i <= MAX_LOGICAL_DATA_LINK; i++) {
408 if (link->datagram_handlers[i]) {
409 pthread_t thread = link->datagram_handlers[i]->thread;
410 length = mq_receive(link->datagram_handlers[i]->llc_down, (char *) buffer, sizeof(buffer), NULL);
411 if (length > 0)
412 break;
413 switch (errno) {
414 case EAGAIN:
(gdb)
Fixing m_queue
Message Size
The default Linux implementation has the maximum message size set to 8192 bytes. That's not a lot of data to be honest, although it would be more than enough for an bridge between Erlang processes for most data. Unfortunately, this is a kernel option, and so to increase it you need to muck with your runtime kernel parameters (/proc/sys/fs/mqueue/msgsize_max).
Maximum Queue Size
The maximum number of messages you can put into the queue before it starts to block the sender is 10 messages. Again, kernel configurable (/proc/sys/fs/mqueue/msg_max), but 10 messages is pretty darn small.
