From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Lance Taylor To: vax@linkdead.paranoia.com Cc: gas2@cygnus.com, baford@schirf.cs.utah.edu Subject: Re: fixing i386 gas for 16-bit code Date: Thu, 20 Jun 1996 08:46:00 -0000 Message-id: <199606201546.LAA05668@sanguine.cygnus.com> References: <199606190541.AAA00489@linkdead.paranoia.com> X-SW-Source: 1996/msg00043.html Date: Wed, 19 Jun 1996 00:41:40 -0500 From: VaX#n8 I was wondering if you know how hard it would be (for me) to fix gas to create 16-bit code properly, especially in the case of SIB (scaled indexed based) addressing modes on the i386. I don't know much about the i386 myself, so I'm CC'ing your note to the gas developers list, gas2@cygnus.com. Perhaps somebody on the list will have some useful information. I have to hand code things like: movb 1(%si), %dh because it flubs the Mod-R/M byte. Another cool thing would be 8-bit offset addressing. Coding all this by hand is hair-pulling material. It is so ugly I chose not to do it :) I used to hand code stuff when I was a kid, but it's pretty horrifying to think that anybody still has to do it. I believe that there are some 16 bit i386 assemblers out there. Would I have to learn bfd? It confused the heck outta me when I looked at the bfd source last time :-/ You shouldn't have to look at BFD for this sort of thing. Ian