[erlang-questions] embedded systems erlang?

[Matthias Lang]

On Monday, December 15, Raoul Duke wrote:

> I see many google hits for things people have done with Erlang
> targeting "embedded" resource constrained systems. But I'm not sure if
> there's like an official build or something for it?

There is no "official" build for "resource constrained" erlang.

But cross compilation, which is a hurdle for many embedded systems, has
been part of the official build for years now (it's definitely in R14B03,
probably appeared around R12 or R13)

> Does everybody hack up their own thing?

Yes, because different people's embedded systems are quite different.

> I'm looking at like 256 K RAM (!)

There's no way you'll get normal Erlang to run in that.

Just starting the shell on R14B03 on a 32 bit ARM CPU uses about 10 MB.
Older versions of Erlang, e.g. R7, were a bit less hungry, maybe 6 MB.
But 256 K is totally out of reach.

Here's erlang:memory() on an ARM, for a newly started emulator which
hasn't done anything other than start the shell:

Erlang R14B03 (erts-5.8.4) [source] [rq:1] [async-threads:0] [kernel-poll:false]

Eshell V5.8.4  (abort with ^G)
1> erlang:memory().
[{total,3488376},
 {processes,679792},
 {processes_used,673232},
 {system,2808584},
 {atom,300553},
 {atom_used,272023},
 {binary,17688},
 {code,1745473},
 {ets,86156}]

the values are in bytes. (The memory use according to the OS is 10 MB for
that emulator)

Matt