Document configuration file & more cleanup

README.md

@@ -5,14 +5,87 @@
 
 A local diffing tool for decompilation projects.
 
-Currently supports:
+Supports:
 - PowerPC 750CL (GameCube & Wii)
 - MIPS (Nintendo 64)
 
+See [Usage](#usage) for more information.
+
 ![Symbol Screenshot](assets/screen-symbols.png)
 ![Diff Screenshot](assets/screen-diff.png)
 
-### License
+## Usage
+
+objdiff works by comparing two relocatable object files (`.o`). The objects are expected to have the same relative path from the "target" and "base" directories.
+
+For example, if the target ("expected") object is located at `build/asm/MetroTRK/mslsupp.o` and the base ("actual") object 
+is located at `build/src/MetroTRK/mslsupp.o`, the following configuration would be used:
+
+- Target build directory: `build/asm`
+- Base build directory: `build/src`
+- Object: `MetroTRK/mslsupp.o`
+
+objdiff will then execute the build system from the project directory to build both objects:
+
+```sh
+$ make build/asm/MetroTRK/mslsupp.o # Only if "Build target object" is enabled
+$ make build/src/MetroTRK/mslsupp.o
+```
+
+The objects will then be compared and the results will be displayed in the UI.
+
+See [Configuration](#configuration) for more information.
+
+## Configuration
+
+While **not required** (most settings can be specified in the UI), projects can add an `objdiff.json` (or `objdiff.yaml`, `objdiff.yml`) file to configure the tool automatically. The configuration file must be located in the root project directory.
+
+```json5
+// objdiff.json
+{
+  "custom_make": "ninja",
+  "target_dir": "build/mp1.0/asm",
+  "base_dir": "build/mp1.0/src",
+  "build_target": true,
+  "watch_patterns": [
+    "*.c",
+    "*.cp",
+    "*.cpp",
+    "*.h",
+    "*.hpp",
+    "*.py"
+  ],
+  "objects": [
+    {
+      "path": "MetroTRK/mslsupp.o",
+      "name": "MetroTRK/mslsupp",
+      "reverse_fn_order": false
+    },
+    // ...
+  ]
+}
+```
+
+- `custom_make` _(optional)_: By default, objdiff will use `make` to build the project.  
+  If the project uses a different build system (e.g. `ninja`), specify it here.
+- `target_dir`: Relative from the root of the project, this where the "target" or "expected" objects are located.  
+  These are the **intended result** of the match.
+- `base_dir`: Relative from the root of the project, this is where the "base" or "actual" objects are located.  
+  These are objects built from the **current source code**.
+- `build_target`: If true, objdiff will tell the build system to build the target objects before diffing (e.g. `make path/to/target.o`).  
+  This is useful if the target objects are not built by default or can change based on project configuration or edits to assembly files.  
+  Requires the build system to be configured properly.
+- `watch_patterns` _(optional)_: A list of glob patterns to watch for changes. ([Supported syntax](https://docs.rs/globset/latest/globset/#syntax))  
+  If any of these files change, objdiff will automatically rebuild the objects and re-compare them.
+- `objects` _(optional)_: If specified, objdiff will display a list of objects in the sidebar for easy navigation.
+  - `path`: Relative path to the object from the `target_dir` and `base_dir`.
+  - `name` _(optional)_: The name of the object in the UI. If not specified, the object's `path` will be used.  
+  - `reverse_fn_order` _(optional)_: Displays function symbols in reversed order.  
+    Used to support MWCC's `-inline deferred` option, which reverses the order of functions in the object file.
+
+
+
+## License
 
 Licensed under either of