After struggling with sucking Bochs 2.3.6(2.3.7), I finally solved the int 13h issue. Then the logo show of my OS works now 
The left pic shows my honey cat, the right one is myself.
I would say till now all the blocking issues have all been cleared in bootloader. From now on, I can devote myself into kernel development totally. (Of course, I will refractory bootloader if needed later when I developing some other components.)
p.s. SourceForge is not that slow than I thought. I've submitted nearly 1.5M data to the server and only about 3 mins elapsed before everything is done. I love SF, except some of its politics views.