Re: Where does ELKS need to go?

David Given <[email protected]> Mon, 21 Apr 2014 23:05:14 +0100
Newsgroups	org.kernel.vger.linux-8086
Message-ID	<[email protected]>
On 4/19/14, 5:45 PM, Harley Laue wrote:
[...]
> I'm pretty sure it's been mentioned in the past, but SDCC might be an
> option (though, I don't think there is a code generator for 8086-80286).
> Edoardo's suggestion of TACK might be a good fit as well. I've had some
> experience with SDCC, but I haven't ever tried TACK. I will say, SDCC
> has a fairly dedicated community behind it and the project is still
> quite active. TACK, however, doesn't seem to have had many commits in
> the last few years.

I'm the maintainer for TACK. It's actually had some development recently
--- and from people who aren't me, too! But unfortunately the design is
rather hostile to RISC architectures. But it's got decent C89 support
and a reasonable 8086 code generator, and it does have the big advantage
over bcc or pcc in that it's a complete toolchain --- it's got a libc,
an assembler and a linker in it, so it can be made to spit out binaries
with no external dependencies.

Adding a new target to TACK is a bit specialist but relatively easy.
Ping me if there's interest.

[...]
>> * What can/does ELKS offer compared to other small OSes such as NuttX?
> Running more than one process (I'm assuming at least.) IIRC, NuttX
> compiles the kernel into the application to run the single application
> on the hardware.

ELKS' big feature is that it's got a userland. Unfortunately I'm not
sure this is particularly useful these days, particularly as the way it
works is strongly dependent on having an MMU (the 8086's segmentation
counts as an MMU here). I doubt whether ELKS could be easily ported to a
non-MMU system. (How do you relocate a running process, for example?)

One option is to turn ELKS into a Unix emulation layer on top of NuttX,
but that would mean giving up a lot of what makes ELKS a Unix. And I'm
afraid that even for the 8086, ELKS has been superceded by Minix 2,
which is a lot more mature and robust than ELKS is.

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