Booting process?

["Noah Yan" <yanyh@xxxxxxxxx>]

I am looking at the code about the booting process of DFL while referring to 
FreeBSD related book.
in DFL source tree for x86, on sys/boot/i386 includes related source code 
for booting,
but I also find another place sys/i386/boot that seems to have all the 
related booting code.
For me, seems that sys/boot/i386 is the actural one, but what is 
sys/i386/boot is used for?

Another question is for the BTX. I know boot2 is linked with btxld and use 
BTX protected environment.
After boot2 load the /boot/loader and jump to it, is the loader still in 
BTX? how about later on the
kernel? If not, the loader or kernel will clean BTX and setup everything 
(such as GDT, IDT, etc) by itself,
right? but how the loader or the kernel get out of the control of BTX?

One more question, why the boot0 need to be moved from 0x7c00 to 0x6000 when 
it loaded?

Thanks very much
Noah