Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!ucbvax!mtxinu!taniwha!paul From: paul@taniwha.UUCP (Paul Campbell) Newsgroups: comp.unix.aux Subject: Re: Raw (More or Less) Ethernet Access in A/UX? Message-ID: <814@taniwha.UUCP> Date: 13 Apr 91 07:27:32 GMT References: <10944@bunny.GTE.COM> <13022@goofy.Apple.COM> Reply-To: paul@taniwha.UUCP (Paul Campbell) Organization: Taniwha Systems Design, Oakland Lines: 48 In article <13022@goofy.Apple.COM> ksand@Apple.COM (Kent Sandvik, 120dB or more) writes: > >A word of warning, the A/UX dev. driver kit is for A/UX 2.0, and u_phys >has changed, and there are some header file changes. It could happen >that the dev. driver kit works OK with most of the 2.0.1 headers/object >files, but the object code will link together a 2.0 kernel, and that's >not exactly what you want for testing on a 2.0.1 system. > Every time I go to a developers conference I rail about the A/UX people changing the kernel data structures out from under developers feet all the time - it's really simple - if you are going to remove/reuse a data structure field by all means do it BUT LEAVE A PAD IN ITS PLACE don't change the offsets to all the other stuff. However everyone nods their heads wisely, sais that they understand the problem and nothing ever seems to change. Can you imagine the havoc it would cause if the MacOS systems people started popping fields out of say Window structures - every MacOS application in the world would break if you did you would get fired!! Well when you do it to us developers in the A/UX world it's just as bad (there are just fewer of us). I figure that getting upgrades to all my users last time you did this cost me about $1,000 (out of my pocket) - and you didn't actually change anything that really affected me (someone just snuck a new field into the middle of the tty structure instead of put it at the end). It's about time we came up with some guidelines for binary compatability a good start would be for Apple Q/A to verify offsets key fields within key data structures and make sure that they don't change from release to release - perhaps developers could nominate the ones that they really care about and we could all come to some agreement Flame off. BTW CommCard drivers don't use anything after u.u_phys so the 2.0 drivers (our version 2.5.2) work under 2.01 too - but I'm sure someone else somewhere is tearing their hair. Paul Campbell Taniwha Systems -- Paul Campbell UUCP: ..!mtxinu!taniwha!paul AppleLink: CAMPBELL.P "But don't we all deserve. More than a kinder and gentler fuck" - Two Nice Girls, "For the Inauguration"