[TUHS] Pre-init initialization

[Clem Cole]

A couple of the commercial systems did this for sure. Linux definitely
picked it up from UNIX practices, although I have no idea/memory of who did
it first.  We used the idea at Stellar (Stellix) and at Masscomp (RTU).
IIRC, a couple of others like Pyramid made have created a RAMFS - but it
was kicking around the UNIX community for a fairly long time - certainly in
the late 1970s - *i.e.* post V7.

FWIW: V7 had /stand which was a funky UNIX-like standalone system that some
applications could be compiled.  The problem was that it was a little
different so you would end up seeing #ifdef STAND in code for things like
fsck, fsdb, even cat.  At Masscomp we ended up with three target
environments for a couple of the system maintenance utilities: the OS,
/stand and the boot ROMS.   This was expensive/a PITA to maintain and keep
straight, and in the case of the boot ROM, space was a huge problem.

The RAMFS idea was created to get rid of at least /stand and IIRC we were
able to drop a number of utilities out of the boot ROM.  I'm not sure how
far they took it.   I left for Stellar and it was always the way Stellix
booted.



On Tue, Aug 6, 2019 at 7:47 PM Grant Taylor via TUHS <tuhs at minnie.tuhs.org>
wrote:

> Do, or did, anything other than Linux use a concept of an initramfs /
> initrd to create a pre-(main)-init initialization environment to prepare
> the system to execute the (main)-init process?
>
>
>
> --
> Grant. . . .
> unix || die
>
>
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