eCos applications and components can be debugged in + traditional ways, with printing statements and debugger + single-stepping, but there are situations in which these + techniques cannot be used. One example of this is when a + program is getting data at a high rate from a real-time + source, and cannot be slowed down or interrupted.
eCos’s infrastructure module provides a + tracing formalism, allowing the + kernel’s tracing macros to be configured in many useful + ways. eCos’s kernel provides instrumentation + buffers which also collect specific + (configurable) data about the system’s history and + performance.
To use eCos’s tracing facilities you must first + configure your system to use tracing. + You should enable the Asserts and Tracing component + (CYGPKG_INFRA_DEBUG) and the + Use tracing component within it + (CYGDBG_USE_TRACING). These + options can be enabled with the Configuration + Tool or by editing the file + BUILD_DIR/pkgconf/infra.h + manually.
You should then examine all the tracing-related options in +the Package: Infrastructure chapter of the eCos Reference +Manual. One useful set of configuration options are: CYGDBG_INFRA_DEBUG_FUNCTION_REPORTS and CYGDBG_INFRA_DEBUG_TRACE_MESSAGE, +which are both enabled by default when tracing is enabled.
The following “Hello world with tracing” shows +the output from running the hello world program (from the Section called eCos Hello World in Chapter 13) that was +built with tracing enabled:
Example 27-1. Hello world with tracing
$ mips-tx39-elf-run --board=jmr3904 hello
+Hello, eCos world!
+ASSERT FAIL: <2>cyg_trac.h [ 623] Cyg_TraceFunction_Report_::set_exitvoid() exitvoid used in typed function
+TRACE: <1>mlqueue.cxx [ 395] Cyg_ThreadQueue_Implementation::enqueue() {{enter
+TRACE: <1>mlqueue.cxx [ 395] Cyg_ThreadQueue_Implementation::enqueue() }}RETURNING UNSET!
+TRACE: <1>mlqueue.cxx [ 126] Cyg_Scheduler_Implementation::add_thread() }}RETURNING UNSET!
+TRACE: <1>thread.cxx [ 654] Cyg_Thread::resume() }}return void
+TRACE: <1>cstartup.cxx [ 160] cyg_iso_c_start() }}return void
+TRACE: <1>startup.cxx [ 142] cyg_package_start() }}return void
+TRACE: <1>startup.cxx [ 150] cyg_user_start() {{enter
+TRACE: <1>startup.cxx [ 150] cyg_user_start() (((void)))
+TRACE: <1>startup.cxx [ 153] cyg_user_start() 'This is the system default cyg_user_start()'
+TRACE: <1>startup.cxx [ 157] cyg_user_start() }}return void
+TRACE: <1>sched.cxx [ 212] Cyg_Scheduler::start() {{enter
+TRACE: <1>mlqueue.cxx [ 102] Cyg_Scheduler_Implementation::schedule() {{enter
+TRACE: <1>mlqueue.cxx [ 437] Cyg_ThreadQueue_Implementation::highpri() {{enter
+TRACE: <1>mlqueue.cxx [ 437] Cyg_ThreadQueue_Implementation::highpri() }}RETURNING UNSET!
+TRACE: <1>mlqueue.cxx [ 102] Cyg_Scheduler_Implementation::schedule() }}RETURNING UNSET!
+TRACE: <2>intr.cxx [ 450] Cyg_Interrupt::enable_interrupts() {{enter
+TRACE: <2>intr.cxx [ 450] Cyg_Interrupt::enable_interrupts() }}RETURNING UNSET!
+TRACE: <2>thread.cxx [ 69] Cyg_HardwareThread::thread_entry() {{enter
+TRACE: <2>cstartup.cxx [ 127] invoke_main() {{enter
+TRACE: <2>cstartup.cxx [ 127] invoke_main() ((argument is ignored))
+TRACE: <2>dummyxxmain.cxx [ 60] __main() {{enter
+TRACE: <2>dummyxxmain.cxx [ 60] __main() (((void)))
+TRACE: <2>dummyxxmain.cxx [ 63] __main() 'This is the system default __main()'
+TRACE: <2>dummyxxmain.cxx [ 67] __main() }}return void
+TRACE: <2>memcpy.c [ 112] _memcpy() {{enter
+TRACE: <2>memcpy.c [ 112] _memcpy() ((dst=80002804, src=BFC14E58, n=19))
+TRACE: <2>memcpy.c [ 164] _memcpy() }}returning 80002804
+TRACE: <2>cstartup.cxx [ 137] invoke_main() 'main() has returned with code 0. Calling exit()'
+TRACE: <2>exit.cxx [ 71] __libc_exit() {{enter
+TRACE: <2>exit.cxx [ 71] __libc_exit() ((status=0 ))
+TRACE: <2>atexit.cxx [ 84] cyg_libc_invoke_atexit_handlers() {{enter
+TRACE: <2>atexit.cxx [ 84] cyg_libc_invoke_atexit_handlers() (((void)))
+
+Scheduler:
+
+Lock: 0
+Current Thread: <null>
+
+Threads:
+
+Idle Thread pri = 31 state = R id = 1
+ stack base = 800021F0 ptr = 80002510 size = 00000400
+ sleep reason NONE wake reason NONE
+ queue = 80000C54 wait info = 00000000
+
+<null> pri = 0 state = R id = 2
+ stack base = 80002A48 ptr = 8000A968 size = 00008000
+ sleep reason NONE wake reason NONE
+ queue = 80000BD8 wait info = 00000000
+ |