Hey, I'm back to working on start.S and I came across a few things.
(I realize others may be working on bootup procedures; they can feel
 free to ignore mine or incorporate it if they wish)

Is the preferred comment style /* C */ or #asm/script/perl/kitchen-sink?

Also, the comment on the int $0x13/2 call is placed too late, and wrong:
the carry flag is the failure indicator, not %al.  Register %al holds 
the number of sectors transferred.  The code, however, is correct.

I'm kind of curious what probs I'll have if I link at segment 0 instead
of 7c00, when entering boot2.

Also, if I wanted to disassemble a program, for example if I wanted to
double-check my opcodes, what tool could I use?
I found out I can probably use "-a" to gas, but in the more general
case of disassembling an executable/object file, what is a good way?

Despite my gripes, the assembly portion of the kernel is more readable
to me than the C parts -- better commenting, very few cryptically-named
data structures.