New build instructions

source/docs/building.md

@@ -8,30 +8,121 @@ This document will explain how to install, test, and run Nimbus on your local ma
 ## Getting Started
 
 - [install Nim](https://bitfalls.com/nim1)
-- be on a command-line friendly system (i.e. access to Terminal / Console / Git Bash / Powershell)
+- be on a command-line friendly system (i.e. access to Terminal / Console / Cmder / [Git Bash](https://git-scm.com) / Powershell)
 
-## Prerequisites
+Alternatively, [download our pre-configured Vagrant box](https://our.status.im/setting-up-a-local-vagrant-environment-for-nim-development/).
 
-- install [RocksDB](https://rocksdb.org/) via official instructions or by running the below commands:
+_Note: the Nimbus build system uses Makefiles to make the process identical across platforms, easy to update, and compatible with any OS. We don't use Nim's package manager Nimble because it's fundamentally broken._
 
-    - on OS X:
-        ```bash
-        brew install rocksdb
-        curl https://nim-lang.org/choosenim/init.sh -sSf | sh 
-        ```
-    - on Linux
-        ```bash
-        sudo apt-get install librocksdb-dev rocksdb # or your own Linux distribution's equivalent
-        curl https://nim-lang.org/choosenim/init.sh -sSf | sh     
-        ```
+### Installing
 
-## Install Nimbus
+Clone Nimbus.
 
 ```bash
-git clone https://github.com/status-im/nimbus
+git clone git@github.com:status-im/nimbus
 cd nimbus
+```
+### Dependencies
+
+To run the Nimbus, we'll need the RocksDB database and a newer version of Nim. On OS X, execute:
+
+```bash
+brew install rocksdb
+curl https://nim-lang.org/choosenim/init.sh -sSf | sh
+```
+
+On Linux, this should do it:
+
+```bash
+sudo apt-get install librocksdb-dev rocksdb # or your own Linux distribution's equivalent
+curl https://nim-lang.org/choosenim/init.sh -sSf | sh
+```
+
+On Windows, please first make sure you have `make` installed - either in the form of `MinGW32make.exe` via [MinGW website](http://www.mingw.org) or regular old make installed through Git Bash or a package manager like Chocolatey:
+
+```bash
+choco install make
+```
+
+_Note - Windows requires you to add things to your PATH environment variable. This is done by simply opening the Start Menu, searching for "Env", selecting "Edit the system environment variables", clicking on Environment Variables in the popup, and then editing the PATH variable in the list by adding a new entry that corresponds to the folder into which you installed your version of `make` (Choco takes care of this for you, only applies if you installed manually)_
+
+Next, run:
+
+```
+make fetch-dlls
+```
+
+or 
+
+```
+mingw32make.exe fetch-dlls
+```
+
+This downloads the rocksdb and sqlitedb DLL files into `nimbus/build` so that the built program can read them.
+
+### Building, Testing, Running
+
+To build Nimbus:
+
+On OS X / Linux:
+
+```bash
+make
+```
+
+On Windows:
+
+```bash
+make
+```
+
+or 
+
+```bash
+mingw32make.exe
+```
+
+The Nimbus client will now be in `build/nimbus` on any OS and can be run with the same command:
+
+```bash
+./build/nimbus
+```
+
+It should synchronize up to block 49439 and then crash, as mentioned above. Look at flags and options with `build/nimbus --help`.
+
+To test, run:
+
+```bash
+make test # (or mingw32make.exe test on Win if you use mingw32)
+```
+
+### Ethereum 2.0
+
+To run and test the Ethereum 2.0 version of Nimbus:
+
+```bash
+git clone git@github.com:status-im/nim-beacon-chain
+cd nim-beacon-chain
+```
+
+This one still uses Nimble, so:
+
+```bash
 nimble install
+```
+
+It is possible that Nimble will get stuck without output, or that it will ask you strange questions like overwriting a dependency that's already installed in the very same project you're installing it to. In any case, confirm if possible, or restart the installation process by canceling (CTRL+C) and re-running the command.
+
+Once done, run:
+
+```bash
 nimble test
 ```
 
-Run Nimbus with `nimbus` or look at flags and options with `nimbus --help`.
+This executes the test written for the Ethereum 2.0 client version of Nimbus. To run the simulation which spins up a few beacon nodes and builds a beacon chain locally (local testnet), run:
+
+```bash
+sh tests/simulation/start.sh
+```
+
+Congrats! You're now running Nimbus for both the Ethereum 1.0 platform, and the coming [Ethereum 2.0](https://our.status.im/tag/two-point-oh).