Thanks at both.
I sit the boot flag in the mmc and when I turn on the tablet it show the NOKIA splash screen, I see that it turn off the video for an instant and show again the splash screen, but finally go in the boot loop. I don't know why can't boot..
I must set something how the master or the super block?

I tried the last method supplied by Kroll, now the tablet show the splash screen of "debug and recovery", and with the mmc I have the same problem of the boot loop.
Without the mmc it boot (till the sound of Nokia and the splash screen of the 2 hands) but it keep in a blank screen!
In this state the bluetooth is working and I can lock the touch screen (it appears the "lock screen" or "unlock screen" message).
I think that the solution is to succeed to boot from a mmc, because the R&D mode can't help in this case.

I wrong something?
Any suggestion?
Thanks.