Compiling TWRP from sources - OTT MXQ (S805)

Hello,
I'm trying to compile TWRP from source for my MXQ (S805) Box.
I've based my device tree on this: https://github.com/TeamWin/android_device_amlogic_k200 modified with the files extracted from a dump of my recovery.img

I'm able to complete the build process, but the box is not able to boot from the resulting recovery.img (It just reboot).
How can I debug? Is there a way to log the problem?

Thank you!

PS: of course I'll upload my recovery.img when it is stable!