File	Date	Author	Commit
kernel_patch	2011-12-18	Martijn Rutten	[6e6209] Initial linux kernel module, kernel patch to cr...
.cproject	2011-12-18	Martijn Rutten	[6e6209] Initial linux kernel module, kernel patch to cr...
.project	2011-12-18	Martijn Rutten	[6e6209] Initial linux kernel module, kernel patch to cr...
COPYING	2011-12-18	Martijn Rutten	[45962e] Added GPL license
Makefile	2011-12-18	Martijn Rutten	[6e6209] Initial linux kernel module, kernel patch to cr...
README	2011-12-18	Martijn Rutten	[719aff] renamed to README
TD_logger.c	2011-12-18	Martijn Rutten	[45962e] Added GPL license
TD_logger.h	2011-12-18	Martijn Rutten	[45962e] Added GPL license
log2tdi	2011-12-18	Martijn Rutten	[45962e] Added GPL license

Read Me

TimeDoctor Logger Linux Component
---------------------------------

usage :
 - compile the kernel module (TD_logger) : make
 - patch your kernel to instrument with logging calls : see example modified fork.c and sched.c (look for #ifdef CONFIG_PHILIPS_LOG)
 - insmod the logging module : (sudo) insmod TD_logger.ko
 - the module uses procfs for interfacing (see TD_logger source for details) : echo reset | status | on | off > /proc/TimeDoctor
 - a dump of the log buffer can be obtained by reading from /proc/TimeDoctor : cat /proc/TimeDoctor > trace.raw
 - the raw buffer can be converted to a TDI file by using the script log2tdi : log2tdi trace.raw > trace.tdi
     (N.B. potential endianess issues issues when target & host are different, see bytes2int32)
 - trace.tdi can be viewed with the Eclipse TimeDoctor viewer

Todo :
 - did not test the kernel patching, instead added some test logging to the 'on' command. (avoids recompiling kernel).
 - Not sure how logging without the module installed works (instrumented kernel calls functions that are not yet there?)
 - module now uses X86 TSC cycle counter ( rdtscll() ). This will not work on ARM, and has issues on X86 (sleep states, frequency changes).
   A portable solution using high resolution timers might be better, could have performance impact, though.
 - CONFIG_LOG_SIZE is now statically define in TD_logger.c Make this a (kernel) config option.
 - The logging module starts logging only when the module is loaded initialized. For starting logging asap. see if the init can be done
   earlier (e.g. using  early_initcall(TD_BufferInit) )