7 Mar
2017
7 Mar
'17
7:52 a.m.
On 06/03/17, Clem Cole wrote:
On Mon, Mar 6, 2017 at 11:20 AM, Joerg Schilling
<schily(a)schily.net> wrote:
I find this hard to believe. Of course code evolves, but I don't really
see anything that looks like original UNIX code in AIX 4.1.3. I would
expect at least a slight semblance. Had they really replaced (almost?)
all code by the time of AIX 4?
aap
The kernel definitely looks like it was written from scratch.
The fact that there are functions like "issig()" make it obvious that the
authors did have access to at least the V6 kernel via the Lions book.
I can say for a fact that is not how it was. AIX was a port starting
with AT&T code originally targeted to run on DEC and Intel Systems.
As I said previously when I ran down the history of AIX, the developers had
AT&T licenses. As I was reminded in an off line discussion with one of
the IBM guys when I was checking to make sure, ISC did the original 386
port for all of AT&T, Intel and IBM (one port - 3 checks). ISC also
started the AIX port, with a number of the folks moving to LCC which was a
step I left out in my previous email sorry, since it was implied when I
said they started with that AT&T 386 stuff (which AT&T got from ISC).
Bottom line.... it was not a rewrite, it was always a port.
...
Companies like DEC, HP and IBM start working with one version of the kernel
or worse yet, the command system and enhance it as they need. But time
moves forward and their version and the rest of the world start to become
different (branch/fork). Linux has been mostly able to keep the kernel
the same, but not the command system.