Various updates when testing with Neotron Desktop BIOS.

* Screen is cleared from the OS side, with the default attributes.
* It now builds a .so file if it can
* The thumb target is not longer the default, as it's a pain to turn off
  default targets to build native (I wish there was --target=native).

Updates to BIOS API 0.6.0

Author: thejpster

.cargo/config

@@ -23,14 +23,21 @@ name = "flash0002"
 test = false
 bench = false
 
+[lib]
+crate-type = ["rlib", "cdylib"]
+
 [profile.release]
 lto = true
 debug = true
 codegen-units = 1
 opt-level = "s"
+panic = "abort"
+
+[profile.dev]
+panic = "abort"
 
 [dependencies]
-neotron-common-bios = "0.1.0"
+neotron-common-bios = { version = "0.6.0", path = "../neotron-common-bios" }
 r0 = "1.0"
 postcard = "0.5"
 serde = { version = "1.0", default-features = false }

Cargo.toml

@@ -1,6 +1,7 @@
 # Neotron OS
 
-This is the Neotron OS. It will run on any system which can execute ARM Thumb v7-M instructions, and has an implementation of the [Neotron BIOS](https://github.com/neotron-compute/Neotron-BIOS).
+This is the Neotron OS. It will run on any system which has an implementation
+of the [Neotron BIOS](https://github.com/neotron-compute/Neotron-BIOS).
 
 ## Status
 
@@ -24,23 +25,30 @@ OpenOCD or some other programming tool running for your particular board. See
 your BIOS instructions for more details.
 
 We compile one version of Neotron OS, but we link it three times to produce
-three binaries:
+three different binaries:
 
 * `flash0002` - is linked to run from address `0x0002_0000`
 * `flash1002` - is linked to run from address `0x1002_0000`
 * `flash0802` - is linked to run from address `0x0802_0000`
 
-```
+```console
 $ git clone https://github.com/neotron-compute/Neotron-OS.git
 $ cd Neotron-OS
-$ git submodule update --init
-$ cargo build --release
-$ ls ./target/thumbv6m-none-eabi/release/flash{10,08,00}02
+$ cargo build --target thumbv6m-none-eabi --release --bins
+$ ls ./target/thumbv6m-none-eabi/release/flash*02
 ./target/thumbv6m-none-eabi/release/flash0002 ./target/thumbv6m-none-eabi/release/flash0802 ./target/thumbv6m-none-eabi/release/flash1002
 ```
 
 Your BIOS should tell you which one you want and how to load it onto your system.
 
+You can also build a *shared object* to load into a Windows/Linux/macOS application.
+
+```console
+$ cargo build --lib
+$ ls ./target/debug/*.so
+./target/debug/libneotron_os.so
+```
+
 ## Changelog
 
 ### Unreleased Changes ([Source](https://github.com/neotron-compute/Neotron-OS/tree/master))

README.md

@@ -1,7 +1,16 @@
+use std::env;
 fn main() {
-    println!("cargo:rustc-link-arg-bin=flash1002=-Tneotron-flash-1002.ld");
-    println!("cargo:rustc-link-arg-bin=flash0802=-Tneotron-flash-0802.ld");
-    println!("cargo:rustc-link-arg-bin=flash0002=-Tneotron-flash-0002.ld");
+
+    match env::var("CARGO_CFG_TARGET_OS").as_deref() {
+        Ok("none") => {
+            println!("cargo:rustc-link-arg-bin=flash1002=-Tneotron-flash-1002.ld");
+            println!("cargo:rustc-link-arg-bin=flash0802=-Tneotron-flash-0802.ld");
+            println!("cargo:rustc-link-arg-bin=flash0002=-Tneotron-flash-0002.ld");                    
+        }
+        _ => {
+            // No args
+        }
+    }
 
     if let Ok(cmd_output) = std::process::Command::new("git")
         .arg("describe")

build.rs

@@ -70,7 +70,8 @@ struct VgaConsole {
 }
 
 impl VgaConsole {
-    const DEFAULT_ATTR: u8 = (2 << 3) | (1 << 0);
+    /// White on Black
+    const DEFAULT_ATTR: u8 = (15 << 3) | 0;
 
     fn move_char_right(&mut self) {
         self.col += 1;
@@ -88,23 +89,16 @@ impl VgaConsole {
         }
     }
 
-    fn read(&self) -> (u8, u8) {
-        let offset =
-            ((isize::from(self.row) * isize::from(self.width)) + isize::from(self.col)) * 2;
-        let glyph = unsafe { core::ptr::read_volatile(self.addr.offset(offset)) };
-        let attr = unsafe { core::ptr::read_volatile(self.addr.offset(offset + 1)) };
-        (glyph, attr)
-    }
-
-    fn find_start_row(&mut self) {
+    fn clear(&mut self) {
         for row in 0..self.height {
-            self.row = row;
-            let g = self.read().0;
-            if (g == b'\0') || (g == b' ') {
-                // Found a line with nothing on it - start here!
-                break;
+            for col in 0..self.width {
+                self.row = row;
+                self.col = col;
+                self.write(b' ', Some(Self::DEFAULT_ATTR));
             }
         }
+        self.row = 0;
+        self.col = 0;
     }
 
     fn write(&mut self, glyph: u8, attr: Option<u8>) {
@@ -253,6 +247,7 @@ impl core::default::Default for Config {
 
 /// Initialise our global variables - the BIOS will not have done this for us
 /// (as it doesn't know where they are).
+#[cfg(target_os = "none")]
 unsafe fn start_up_init() {
     extern "C" {
 
@@ -269,6 +264,11 @@ unsafe fn start_up_init() {
     r0::init_data(&mut __sdata, &mut __edata, &__sidata);
 }
 
+#[cfg(not(target_os = "none"))]
+unsafe fn start_up_init() {
+    // Nothing to do
+}
+
 // ===========================================================================
 // Public functions / impl for public types
 // ===========================================================================
@@ -279,6 +279,9 @@ unsafe fn start_up_init() {
 pub extern "C" fn main(api: &'static bios::Api) -> ! {
     unsafe {
         start_up_init();
+        if (api.api_version_get)() != neotron_common_bios::API_VERSION {
+            panic!("API mismatch!");
+        }
         API = Some(api);
     }
 
@@ -296,7 +299,7 @@ pub extern "C" fn main(api: &'static bios::Api) -> ! {
                 row: 0,
                 col: 0,
             };
-            vga.find_start_row();
+            vga.clear();
             unsafe {
                 VGA_CONSOLE = Some(vga);
             }