add different requirements for different actions

README.md

@@ -7,7 +7,7 @@ information from GbaTek, Tonc, and the existing
 Note that this currently contains no documentation of any kind, unless you count
 examples as documentation.
 
-## Requirements
+## Build Requirements
 
 * Nightly rust, probably quite a recent version.
 * arm eabi binutils 
@@ -15,6 +15,22 @@ examples as documentation.
     * Alpine: binutils-arm-none-eabi
     * Arch Linux and derivatives: arm-none-eabi-binutils
 
+## Test Requirements
+
+* need a recent mgba (known to work on 0.8.4+)
+* xvfb
+* [corwinkuiper/mgba-test-runner](https://github.com/corwinkuiper/mgba-test-runner)
+    * `cargo install --git https://github.com/corwinkuiper/mgba-test-runner.git`
+
+## Real Hardware Build
+
+* Need gbafix, rust implementation can be installed with `cargo install gbafix`.
+* On compiled elf file, additionally need to
+```bash
+arm-none-eabi-objcopy -O binary {input-elf} {output-gba}
+gbafix {output-gba}
+```
+
 ## Stability
 
 0% stable, I have no problems making drastic changes in the API in order to make