Howto: Building the espruino code

Well, there were lots of fun hurdles, but I finally got a working build environment that can build itself automagically. The instructions are the same as before, with a few extensions:

• after the vm is created, stlink is built (more on this below)
  
• after that, arm-eabi-toolchain from jsnyder (https://github.com/jsnyder/arm-eabi-toolchain) is installed
  
• on my machine, it took about an hour (all but maybe 10 minutes of this is building using the jsnyder/arm-eabi-toolchain makefile)
  
  

It works! I've been able to build for my STM32F4DISCOVERY, flash it using stlink, and use screen to get to the virtual terminal - all within the vm.

I wish it didn't take so long. For those more familiar with the toolchain, is an hour normal? I tried adding some settings to the vm to use more cores and added 'PROCS=2' before my make statement, but that didn't seem to change anything.

Another option is I could just create an image of the vm at this state and that could be hosted somewhere (probably not in this repository since it would be fairly large). However, it would be much faster to setup for the first time.

Please let me know how it goes if you give it a try. I hope this is useful to others ;)