Tweak the code to handle intercepting BIOS calls to int 0x15 to shave another 16 bytes off of BTX (and thus boot2): - Compare against the value of %eax that is saved on the stack instead of   loading it into %eax (which requires saving the current %eax on the   stack). - Use %ch to examine the keyboard flag state in the BIOS to see if   Ctrl-Alt-Del is pressed instead of %al so we don't have to save %eax on   the stack anymore.
Tweak the code to handle intercepting BIOS calls to int 0x15 to shave
another 16 bytes off of BTX (and thus boot2):
- Compare against the value of %eax that is saved on the stack instead of
  loading it into %eax (which requires saving the current %eax on the
  stack).
- Use %ch to examine the keyboard flag state in the BIOS to see if
  Ctrl-Alt-Del is pressed instead of %al so we don't have to save %eax on
  the stack anymore.

MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase