Re: [TUHS] Abstractions

[Warner Losh <imp@bsdimp.com>]

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On Tue, Feb 23, 2021, 7:47 PM Greg A. Woods <woods@robohack.ca> wrote:

> At Tue, 23 Feb 2021 16:15:52 -0500, Henry Bent <henry.r.bent@gmail.com>
> wrote:
> Subject: Re: [TUHS] Abstractions
> >
> > It's also worth
> > pointing out that NetBSD, in addition to having a separate /bin and
> > /usr/bin, has /rescue which has a large selection of statically linked
> > binaries.
>
> Indeed.  However /rescue is really just a hack to avoid the problems
> that occur when basic tools are dynamic-linked.
>
> My vastly preferred alternative is to static-link everything.
>
> Of course with C libraries these days that means the binaries can be
> rather large -- albiet still relatively small in comparison to modern
> disks.
>
> In any case I've also built NetBSD such that all of the base system
> binaries are linked together into one binary (we call this "crunchgen",
> but Linux usually calls it "Busybox(tm)").  I decided to put all the bin
> directories together into one for the ultimate savings of space and time
> and effort, but it would be trivial to keep the root and /usr split for
> better managing application-specific embedded systems.
>
> This hard-static-linking of everything into one binary results in a
> surprisingly small, indeed very tiny, system.  For i386 (32-bit) it
> could probably boot multiuser in about 16mb of RAM.
>

I booted a FreeBSD/i386 4 system, sans compilers and a few other things,
off 16MB CF card in the early 2000s. I did both static (one binary) and
dynamic and found dynamic worked a lot better for the embedded system...

I also did a 8MB PoC router and data logger image that was stripped to the
bone.

PicoBSD fit onto a 1.44MB floppy as lat as FreeBSD 4 and made a good
firewall...

Warner

What I've got so far is a bootable image file of a "complete"
> NetBSD-5/i386 systems that's just a tiny bit over 7Mb.  It contains a
> kernel and a ramdisk image with a 12Mb filesystem containing a crunchgen
> binary with almost everything in it (247 system programs, including all
> the networking tools, but no named, and no toolchain, no mailer, and no
> manual pages -- not atypical of what was delivered with some commercial
> unix systems of days gone by, but of course updated with modern things
> like ssh, etc..)
>
> --
>                                         Greg A. Woods <gwoods@acm.org>
>
> Kelowna, BC     +1 250 762-7675           RoboHack <woods@robohack.ca>
> Planix, Inc. <woods@planix.com>     Avoncote Farms <woods@avoncote.ca>
>

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