unusual bare metal target: Amazon Dash

[Rikki Cattermole via Digitalmars-d-learn]

On 18/08/2015 1:32 p.m., Laeeth Isharc wrote:
> I don't know whether D can run on one, but from a quick look perhaps
> feasible.  Running D on something like this (perhaps it's underpowered,
> but looked to have similar spec to what people had been doing with
> related ARM cortex processors) would certainly make the point very vivid
> that it can be a bare metal programming language.
>
> Only 1Mb of flash RAM for the program - is that enough?
>
> https://learn.adafruit.com/dash-hacking-bare-metal-stm32-programming/programming
>
> https://learn.adafruit.com/dash-hacking-bare-metal-stm32-programming/overview
>
>
> The Amazon Dash button is a tiny device that orders products from
> Amazon.com at the press of a button.  It's designed to be put wherever
> you store consumeables like paper towels, trash bags, etc. so that you
> can easily order more when they run out.  The Dash is great at what it's
> designed to do, but did you know inside the Dash is a powerful ARM
> Cortex-M3 processor and WiFi module that are very similar to wireless
> development boards like the Particle Photon?  You'll even find there are
> easily accessible test pads on the Dash which allow you to reprogram its
> CPU and turn it into your own $5 internet button!  This guide will
> explore how to take apart the Dash and reprogram its CPU to run your own
> code.
> ...
> The CPU is a STM32F205RG6 processor which is an ARM Cortex-M3 that can
> run up to 120mhz and has 128 kilobytes of RAM and 1 megabyte of flash
> memory for program storage.
> The WiFi module is a BCM943362 module which in combination with the CPU
> make it a platform for Broadcom's WICED SDK.
> There's a 16 megabit SPI flash ROM which is typically used in
> conjunction with the WICED SDK for storing application data.
> An ADMP441 microphone is connected to the CPU and used by the Dash iOS
> application to configure the device using the speaker on a phone/tablet.
> There's a single RGB LED and a button.

By what you are saying, I believe it should be doable.
Although I'm a little worried for the WiFi support. Do you need to 
include the code to drive it beyond wrap up some communication to it?

1mb flash should be enough to run D code on it. If you strip out a good 
percentage of druntime and definitely no Phobos.
Although you may be able to mark and use some of that 16mb flash rom as 
executable code storage. If that's so, you'll be in a good place to have 
more then 1mb. It would require some clever runtime linking tricks however.

I'm probably not the best person to go more in depth about it or the 
specific chips. So I won't. Most of my knowledge comes from reading what 
others says and talking with Jens Bauer.