There is a large body of code, and a bunch of vectoring through tables, within ld.so.1 that support the loading/relocation and symbol lookup of 4.x applications.
There's AOUT processing in exec() and mmapobj() too. And we've had oodles of fun massaging the Unified Process Model into being able to cope with two lib's within the same process (required to support sbcp's dependencies and the 4.x app). I've wanted to nuke the ld.so.1 4.x stuff a number of times, and as recently as the mmapobj() project, visited the subject again. Yes, we had to do extra work in mmpobj to make sure 4.x objects could be mapped - was it worth the effort? It's always been interesting to learn that 4.x binaries still exist. Some live in the bin directories of those watching this alias (you know who you are :-). And it wasn't so long ago that we relied on them internally (the netinstall "addclient" I recall?). Which has always made us wonder, if *we're* still using 4.x binaries then might our customers be using them too? The result is that I always backed down and left the 4.x stuff (at least in ld.so.1) as it was. I like the idea of a branded zone. I don't have a concrete opinion on the 4.x support. If there was a time for its removal, now seems as good as any. And it would certainly simplify some of my life. The counter argument is that it works (to some degree - there are only a handful of binaries I know of that I ever use to verify it's functionality), and that some customer might still be using it. The trouble is that we think it needs no more support, ie. the code's done, but mmapobj() proved we had to go do extra work to keep supporting it. I'd really like to not have to visit 4.x again. One question I've always had is why do we keep building the libraries etc? For example, to support 4.x we have /usr/lib/ld.so, which is a 4.x binary (which we probably couldn't rebuild again if we tried, the last 4.x machine I know of got taken off the net long ago), so why couldn't we package up the 4.x components and simply not build them again. We haven't changed them in years, have we? If a customer wanted them we could point them at the package, but beyond that, they're done, and they'd be out of our source base. Just thinking out loud. -- Rod.
