I've just committed a bunch of changes to the i386 boot code.
Besides some cleanup and code sharing, there is now
information collected at strategic places in the code about
console setting, boot disk or network interface and name of the
booted kernel.
This is what I considered useful; the framework is quite
extensible, and I'm open for suggestions.
Obviously these data have to be passed to te kernel at startup
somehow (1 pointer is sufficient). I see two easy possibilities:
a) use the "cyloffset" field which is unused for ages
b) use the current boot device field as a selector - there is
  a magic value in the upper 4 bits which we can assign a
  new reserved value to. If this new magic is present, an
  additional argument is on the stack.
I like "a" more because one can easily maintain backwards
compatibility this way - the bootloader can pass both styles
at once.

Is there something what would break if I implemented "a"?
Are there systems out which use the "cyloffset"?

best regards
Matthias Drochner