question about boot code

[fretre]

1.  I try to learn something about boot code with version 3.0. I
    wander whether I can begin with biosboot?(/usr/src/sys/i386/
    boot/biosboot)
2.  The initialized data will be loaded into memory after kernel
    text during boot stage. And where is the file that the
    initialized data is defined in? and
3.  What's the file name?

                                Thanks a lot from Fre Tre
                                <fre...@163.net>
                                China