suddenly, beagleboard xm board is unable to boot and load kernel

Could be something very different, but we’ve had SD cards go flakey on us. There has been discussion about this here and elsewhere. Apparently, Quality Varies, and Size Matters (or at least, it may help…). Some links I’ve collected :

http://forum.xda-developers.com/showthread.php?t=1947560 A blog discussion SD cards in depth
https://groups.google.com/forum/?fromgroups=#!category-topic/beagleboard/bPMNZ0Qz-rg Another discussion, praising SanDisk Ultra Mobile and Samsung Plus microSD, perhaps anecdotally
http://raspberrypi.stackexchange.com/questions/169/how-can-i-extend-the-life-of-my-sd-card A forum discussion on sd card wear with more good links in it.
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=19554 Another forum post with a long rambling discussion about wear leveling, especially as handled by Linux systems.

thanks, but who and where can i get the exact answer?

You would need to let someone else have your board and take a look at it. Hard to debug issues with only email messages. Creating a new SD card would be the next logical step. If that works, then that is answer.

Gerald

i took new 8 gb sd card, and did full copy of original card's
backup..............then also same result( i do copy the back up by
following method:
i first copy MLO file, then uEnv.text, u-boot.bin file. Then i untar
the zipped file of root file system in ext3 partion. then i copy the
uimage file in fat partition. that's it).

now what shoul i do? i don't know anyone nearby who knows beagleboard.
is there any center in india for check up of beagleboard or detailed
website regarding beagleboard or its problems?

Follow the instructions found here to make your card using the latest image. Do exactly as it says. No deviations!

Check your board out using that. That will tell you if your board has a HW issue or not that is preventing it from booting.

http://circuitco.com/support/index.php?title=BeagleBoard-xM

Gerald

same output came after doing things on above link