Better instructions, version bump.

Author: schulzch

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "openvr_sys"
-version = "2.0.2"
+version = "2.0.3"
 authors = [
     "Colin Sherratt",
     "Erick Tryzelaar",

README.md

@@ -1,7 +1,28 @@
-To update, update the submodule then bindgen on wrapper.h
+# openvr-sys
 
-The following structs must be marked `#[cfg_attr(unix, repr(packed))]` to work around OpenVR's broken ABI on Linux/OSX:
-- `VRControllerState_t`
-- `RenderModel_TextureMap_t`
-- `RenderModel_t`
-- `VREvent_t`
+Contains function definitions for the [OpenVR](https://github.com/ValveSoftware/openvr) library. Use the `openvr` crate, unless you know what you are doing.
+
+## Instructions for updating OpenVR
+
+1. `git submodule update --init --recursive` (initial checkout only)
+1. `git submodule foreach git pull origin master` to update the submodule 
+1. `cargo build --features "buildtime_bindgen"` to update the bindings
+1. Apply the workaround for broken OpenVR ABIs, if required
+
+## Workaround for broken OpenVR ABIs (Linux/macOS only)
+
+Search for packed structs in `headers/openvr.h`, i.e., `#pragma pack( push, 4 )`. Currently, that is:
+
+```
+VRControllerState_t
+RenderModel_TextureMap_t
+RenderModel_t
+VREvent_t
+```
+
+Depending on what bindgen did parse, you have to replace a bunch of `#[repr(C)]` and `#[repr(C, packed(4))]` precending those structs in `bindings.rs` with:
+
+```rust
+#[repr(C)]
+#[cfg_attr(unix, repr(packed(4)))]
+```