Better Windows instructions.

Author: thejpster

README.md

@@ -21,7 +21,7 @@ $ export LIBRARY_PATH="$LIBRARY_PATH:$(brew --prefix)/lib"
 
 You will need to re-run the `export` command before you re-build the application.
 
-## Building
+## Building on Linux
 
 Build and run this BIOS (and use it to boot Neotron OS) with...
 
@@ -44,6 +44,23 @@ The file `libneotron_os.so` is not supplied. You can build it with:
 ~/neotron-os $ cp ./target/release/libneotron_os.so ~/Neotron-Desktop-BIOS
 ```
 
+## Building on Windows
+
+1. Install and bootstrap [vcpkg](https://github.com/microsoft/vcpkg)
+2. Install the SDL2 libraries with vcpkg:
+
+  ```console
+  C:\Users\user\Documents\vcpkg> ./vcpkg.exe install sdl2-ttf:x64-windows sdl2:x64-windows sdl2-mixer:x64-windows sdl2-gfx:x64-windows sdl2-ttf:x64-windows sdl2-image:x64-windows
+  ```
+
+3. Set your PATH, INCLUDE and LIB to include the directories in your vcpkg install folder:
+
+  ```console
+  C:\Users\user\Documents> set PATH=%PATH%;C:\Users\user\Documents\vcpkg\installed\x64-windows\bin
+  C:\Users\user\Documents> set INCLUDE=%INCLUDE%;C:\Users\user\Documents\vcpkg\installed\x64-windows\include
+  C:\Users\user\Documents> set LIB=%LIB%;C:\Users\user\Documents\vcpkg\installed\x64-windows\lib
+  ```
+
 ## Features
 
 * GUI window with pixel-perfect video rendering

src/main.rs

@@ -720,9 +720,15 @@ fn main() {
 	}
 
 	// Process args
-	info!("Loading OS from {}", args.os.display());
-	let lib = unsafe { libloading::Library::new(args.os).expect("library to load") };
-	println!("Loaded!");
+	let mut lib = None;
+	for arg in std::env::args() {
+		if let Some(os_path) = arg.strip_prefix("--os=") {
+			info!("Loading OS from {:?}", os_path);
+			lib = unsafe { Some(libloading::Library::new(os_path).expect("library to load")) };
+			println!("Loaded!");
+		}
+	}
+	let lib = lib.expect("Fetching --os=filename from args");
 
 	// Make a window
 	let mut engine = PixEngine::builder()
@@ -751,7 +757,7 @@ fn main() {
 		drop(queue);
 		info!("Video init complete. OS starting...");
 		let main_func: libloading::Symbol<unsafe extern "C" fn(api: &'static common::Api) -> !> =
-			lib.get(b"main").expect("main() found");
+			lib.get(b"os_main").expect("os_main() not found");
 		main_func(&BIOS_API);
 	});
 
@@ -798,7 +804,7 @@ extern "C" fn serial_get_info(_device: u8) -> common::Option<common::serial::Dev
 /// options are invalid for that serial device.
 extern "C" fn serial_configure(_device: u8, _config: common::serial::Config) -> common::Result<()> {
 	debug!("serial_configure()");
-	common::Result::Err(common::Error::Unimplemented)
+	Err(common::Error::Unimplemented).into()
 }
 
 /// Write bytes to a serial port. There is no sense of 'opening' or
@@ -812,7 +818,7 @@ extern "C" fn serial_write(
 	_timeout: common::Option<common::Timeout>,
 ) -> common::Result<usize> {
 	debug!("serial_write()");
-	common::Result::Err(common::Error::Unimplemented)
+	Err(common::Error::Unimplemented).into()
 }
 
 /// Read bytes from a serial port. There is no sense of 'opening' or
@@ -826,7 +832,7 @@ extern "C" fn serial_read(
 	_timeout: common::Option<common::Timeout>,
 ) -> common::Result<usize> {
 	debug!("serial_read()");
-	common::Result::Err(common::Error::Unimplemented)
+	Err(common::Error::Unimplemented).into()
 }
 
 /// Get the current wall time.
@@ -874,15 +880,15 @@ extern "C" fn time_clock_set(time: common::Time) {
 /// battery-backed SRAM.
 extern "C" fn configuration_get(_buffer: common::ApiBuffer) -> common::Result<usize> {
 	debug!("configuration_get()");
-	common::Result::Err(common::Error::Unimplemented)
+	Err(common::Error::Unimplemented).into()
 }
 
 /// Set the configuration data block.
 ///
 /// See `configuration_get`.
 extern "C" fn configuration_set(_buffer: common::ApiByteSlice) -> common::Result<()> {
 	debug!("configuration_set()");
-	common::Result::Err(common::Error::Unimplemented)
+	Err(common::Error::Unimplemented).into()
 }
 
 /// Does this Neotron BIOS support this video mode?
@@ -981,7 +987,7 @@ extern "C" fn video_get_framebuffer() -> *mut u8 {
 /// The pointer must point to enough video memory to handle the current video
 /// mode, and any future video mode you set.
 unsafe extern "C" fn video_set_framebuffer(_buffer: *const u8) -> common::Result<()> {
-	common::Result::Err(common::Error::Unimplemented)
+	Err(common::Error::Unimplemented).into()
 }
 
 /// Find out whether the given video mode needs more VRAM than we currently have.
@@ -1185,7 +1191,7 @@ fn convert_keycode(key: Key) -> common::hid::KeyCode {
 /// Control the keyboard LEDs.
 extern "C" fn hid_set_leds(_leds: common::hid::KeyboardLeds) -> common::Result<()> {
 	debug!("hid_set_leds()");
-	common::Result::Err(common::Error::Unimplemented)
+	Err(common::Error::Unimplemented).into()
 }
 
 /// Wait for the next occurence of the specified video scan-line.
@@ -1523,6 +1529,7 @@ impl MyApp {
 		for glyph in 0..=255 {
 			for palette_entry in PALETTE.iter().take(Self::NUM_FG) {
 				let fg = RGBColour::from_packed(palette_entry.load(Ordering::Relaxed));
+				info!("Drawing {glyph} in {:06x}", fg.as_packed());
 				let texture_id = if texture_buffer.len() > slot {
 					texture_buffer[slot]
 				} else {
@@ -1631,6 +1638,7 @@ impl AppState for MyApp {
 		let num_rows = self.mode.text_height().unwrap();
 		// FRAMEBUFFER is an num_cols x num_rows size array of (u8_glyph, u8_attr).
 		for row in 0..num_rows {
+			let y = row * font_height;
 			for col in 0..num_cols {
 				let cell_no = (row * num_cols) + col;
 				let byte_offset = usize::from(cell_no) * 2;