Expand pre-req instructions in hello_world readme. (#351)

* Expand pre-req instructions in hello_world readme.

* Docs: cargo-playdate. Switch development instructions from git remote to locally checked out copy.

---------

Co-authored-by: Alexander Koz. <[email protected]>

cargo/README.md

@@ -6,52 +6,72 @@ It can build programs written in Rust, manage assets, build package for Playdate
 Usually it builds static or dynamic libraries for sim and hardware,
 but also it can build executable binaries for hardware and this method produces highly optimized output with dramatically minimized size (thanks to DCE & LTO)\*.
 
-\* For executable binaries use `--no-gcc` argument._
+\* _For executable binaries use `--no-gcc` argument._
+
+### Platform specific pre-req install instructions
+
+MacOS:
+
+1. Install the [PlaydateSDK](https://play.date/dev/) (by default installs into `~/Developer/PlaydateSDK`)
+1. Set PLAYDATE_SDK_PATH env var: `export PLAYDATE_SDK_PATH="$HOME/Developer/PlaydateSDK"`
+1. Install cmake: `brew install cmake`
+1. Install rust nightly: `rustup toolchain install nightly`
+1. Arm toolchain is included with PlaydateSDK.
+
+Ubuntu Linux:
+1. Install the [PlaydateSDK](https://play.date/dev/) - remember where you extracted it.
+1. Set PLAYDATE_SDK_PATH env var: `export PLAYDATE_SDK_PATH="/path/to/PlaydateSDK-2.x.x/"`
+1. Install cmake: `sudo apt-get install cmake`
+1. Install rust nightly: `rustup toolchain install nightly`
+1. Install arm toolchain: `sudo apt-get install gcc-arm-none-eabi`
+1. Install libudev: `sudo apt-get install libudev-dev`
+
+Windows:
+1. Install the [PlaydateSDK](https://play.date/dev/) (by default installs into `~/Documents/PlaydateSDK`)
+1. Set PLAYDATE_SDK_PATH
+    1. windows+r, run: `sysdm.cpl`
+    2. Advanced Tab -> Environment Variables -> New
+    3. Variable name: `PLAYDATE_SDK_PATH`
+    4. Variable value: `C:\Users\username\Documents\PlaydateSDK`
+1. Install CMake: [cmake downloads](https://cmake.org/download/)
+1. Install rust nightly: `rustup toolchain install nightly`
+1. Install arm toolchain: [arm gnu toolchain downloads](https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads). Filename will be like 'arm-gnu-toolchain-13.2.rel1-mingw-w64-i686-arm-none-eabi.exe'.
+1. Add arm toolchain and cmake to PATH environment:
+    1. windows+r, run: `sysdm.cpl`
+    2. Advanced Tab -> Environment Variables.
+    3. Find `Path` and click `Edit`
+    4. Click `New` and add `C:\Program Files\CMake\bin`
+    4. Click `New` and add `C:\Program Files (x86)\Arm GNU Toolchain arm-none-eabi\13.2 Rel1\bin`
 
 
-
-## Prerequisites
-
-To build `cargo-playdate` you're need:
-1. Rust __nightly__ toolchain
-
-To build programs using `cargo-playdate` you need:
-1. Rust __nightly__ toolchain
-1. [Playdate SDK][sdk]
-   - Ensure that env var `PLAYDATE_SDK_PATH` points to the SDK root
-1. Follow the [official documentation][doc-prerequisites]
-   - Ensure that `arm-none-eabi-gcc` or `gcc-arm-none-eabi` in your `PATH`
-
  <!-- TODO: Make gcc optional -->
 
-To run on sim or dev with `cargo-playdate`:
-1. Linux only:
-  - `libudev`, follow [instructions for udev crate][udev-crate-deps].
-1. Windows only:
-  - `powershell` (used as fallback)
+See also: [Inside Playdate with C: Prerequisites](https://sdk.play.date/Inside%20Playdate%20with%20C.html#_prerequisites)
 
-[sdk]: https://play.date/dev/#cardSDK
-[doc-prerequisites]: https://sdk.play.date/Inside%20Playdate%20with%20C.html#_prerequisites
-[rusb]: https://crates.io/crates/rusb
-
-
-## Installation
+## Cargo-Playdate Installation
 
 ```bash
-cargo install cargo-playdate
-# or
-cargo install --git="https://github.com/boozook/playdate.git" --bin=cargo-playdate
+cargo +nightly install cargo-playdate
+cargo +nightly playdate --version
 ```
 
+Or install to use bleeding edge bits from a local git clone:
+```bash
+mkdir ~/code
+cd ~/code
+git clone https://github.com/boozook/playdate.git
+cargo +nightly install --path="$HOME/code/playdate/cargo" cargo-playdate
+```
 
 ## Hello World
 
 Generate new project using `new` or `init` command.
 
 ```bash
-mkdir hello-world && cd $_
-cargo playdate init --lib --full-metadata --deps="playdate"
-cargo playdate run
+mkdir -p ~/code/pd-hello/
+cd ~/code/pd-hello/
+cargo +nightly playdate init --lib --full-metadata --deps="playdate"
+cargo +nightly playdate run
 ```
 
 > Note, there are more options for this command, e.g. `--deps="sys:git, controls:git"`.