On Tuesday 04 January 2005 08:36 pm, Peter Edwards wrote: > I don't have a box I can test this on, but this looks like a definite > candidate to get > 3 more bytes: > > --- boot0.S 24 Nov 2004 15:39:04 -0000 1.12 > +++ boot0.S 5 Jan 2005 01:27:31 -0000 > _at__at_ -314,8 +314,7 _at__at_ > cmpw $MAGIC,0x1fe(%bx) # Bootable? > jne main.10 # No > pushw %si # Save > - movw $crlf,%si # Leave some > - callw puts # space > + callw putn # Leave space > popw %si # Restore > jmp *%bx # Invoke bootstrap > > If my arithmetic is correct, that leaves us wanting one more byte. > I don't get the save/restore of %si at the end, and judging by the > comment, someone else didn't either. It could be of some use to the > chained loader, but our boot1.S doesn't do anything with it. This actually changes behavior I think (the earlier code outputs two blank lines, the second only one). However, the push and pop of %si probably can go. I think the save/restore there is just pedantic save/restore around puts. -- John Baldwin <jhb_at_FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.orgReceived on Thu Jan 06 2005 - 20:21:21 UTC
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