Add some mode demos, and a palette IOCTL.

Author: thejpster

Cargo.lock

@@ -51,13 +51,27 @@ fn packages() -> Vec<nbuild::Package> {
             testable: nbuild::Testable::All,
         },
         // *** utilities ***
+        nbuild::Package {
+            name: "desktop",
+            path: std::path::Path::new("./utilities/desktop/Cargo.toml"),
+            output_template: Some("./target/{target}/{profile}/desktop"),
+            kind: nbuild::PackageKind::Utility,
+            testable: nbuild::Testable::No,
+        },
         nbuild::Package {
             name: "flames",
             path: std::path::Path::new("./utilities/flames/Cargo.toml"),
             output_template: Some("./target/{target}/{profile}/flames"),
             kind: nbuild::PackageKind::Utility,
             testable: nbuild::Testable::No,
         },
+        nbuild::Package {
+            name: "logo",
+            path: std::path::Path::new("./utilities/logo/Cargo.toml"),
+            output_template: Some("./target/{target}/{profile}/logo"),
+            kind: nbuild::PackageKind::Utility,
+            testable: nbuild::Testable::No,
+        },
         nbuild::Package {
             name: "neoplay",
             path: std::path::Path::new("./utilities/neoplay/Cargo.toml"),

nbuild/src/main.rs

@@ -850,6 +850,16 @@ pub const GFX_COMMAND_MOVE_CURSOR: u64 = 3;
 /// The start position is the cursor position. The cursor is updated to the final position.
 pub const GFX_COMMAND_DRAW_LINE: u64 = 4;
 
+/// Set a palette entry
+///
+/// The command contains [ <padding> | II | RR | GG | BB ]
+///
+/// II, RR, GG and BB are 8-bit values where II is the index into the 256 long
+/// palette, and RR, GG and BB are the 24-bit RGB colour for that index.
+///
+/// Use [`set_palette_value`] to construct a value.
+pub const GFX_COMMAND_SET_PALETTE: u64 = 5;
+
 /// Handle framebuffer-specific ioctls
 fn ioctl_gfx(state: &mut GfxState, command: u64, value: u64) -> neotron_api::Result<u64> {
     let mut lock = crate::VGA_CONSOLE.lock();
@@ -1003,6 +1013,14 @@ fn ioctl_gfx(state: &mut GfxState, command: u64, value: u64) -> neotron_api::Res
             state.cursor_y = new_y;
             neotron_api::Result::Ok(0)
         }
+        GFX_COMMAND_SET_PALETTE => {
+            let index = (value >> 24) as u8;
+            let rgb_packed = (value & 0xFFFFFF) as u32;
+            let api = crate::API.get();
+            let rgb_colour = neotron_common_bios::video::RGBColour::from_packed(rgb_packed);
+            (api.video_set_palette)(index, rgb_colour);
+            neotron_api::Result::Ok(0)
+        }
         _ => neotron_api::Result::Err(neotron_api::Error::InvalidArg),
     }
 }

neotron-os/src/program.rs

@@ -0,0 +1,12 @@
+[package]
+name = "desktop"
+version = "0.1.0"
+edition = "2021"
+license = "MIT OR Apache-2.0"
+authors = ["Jonathan 'theJPster' Pallant <neotron@thejpster.org.uk>"]
+description = "Shows the Windows 95 desktop"
+
+[dependencies]
+neotron-sdk = { workspace = true }
+
+# See workspace for profile settings

utilities/desktop/Cargo.toml

@@ -0,0 +1,3 @@
+# Desktop
+
+Displays a raw 640x480 bitmap in 16 colour mode.

utilities/desktop/README.md

@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo:rustc-link-arg-bin=desktop=-Tneotron-cortex-m.ld");
+}

utilities/desktop/build.rs

@@ -0,0 +1,103 @@
+//! Logic for the vidtest utility
+
+#![no_std]
+#![deny(missing_docs)]
+
+use core::{cell::UnsafeCell, fmt::Write};
+
+// Big enough for our Mode 5 (640 x 480 @ 4bpp) logo
+struct RacyBuffer {
+    inner: UnsafeCell<[u8; 320 * 480]>,
+}
+
+unsafe impl Sync for RacyBuffer {}
+
+static FRAMEBUFFER: RacyBuffer = RacyBuffer {
+    inner: UnsafeCell::new(*include_bytes!("desktop.raw")),
+};
+
+/// Entry point to the program
+pub fn main() -> i32 {
+    let mut stdout = neotron_sdk::stdout();
+
+    let Some(mode) = neotron_sdk::VideoMode::try_from_u8(5) else {
+        _ = writeln!(stdout, "Invalid mode");
+        return -1;
+    };
+
+    let handle: Result<_, _> = neotron_sdk::File::open(
+        neotron_sdk::path::Path::new("GFX:").unwrap(),
+        neotron_sdk::Flags::WRITE,
+    );
+    let Ok(handle) = handle else {
+        return -1;
+    };
+    unsafe {
+        // point at our canned data
+        if handle
+            .ioctl(
+                neotron_sdk::ioctls::gfx::COMMAND_CHANGE_MODE,
+                neotron_sdk::ioctls::gfx::change_mode_value(
+                    mode,
+                    FRAMEBUFFER.inner.get() as *mut u32,
+                ),
+            )
+            .is_err()
+        {
+            return -2;
+        }
+    }
+
+    for (index, entry) in PALETTE.iter().enumerate() {
+        unsafe {
+            // load the palette
+            if handle
+                .ioctl(
+                    neotron_sdk::ioctls::gfx::COMMAND_SET_PALETTE,
+                    neotron_sdk::ioctls::gfx::set_palette_value(
+                        index as u8,
+                        entry.0,
+                        entry.1,
+                        entry.2,
+                    ),
+                )
+                .is_err()
+            {
+                return -2;
+            }
+        }
+    }
+
+    wait_for_key();
+
+    0
+}
+
+fn wait_for_key() {
+    let stdin = neotron_sdk::stdin();
+    let mut buffer = [0u8; 1];
+    while let Ok(0) = stdin.read(&mut buffer) {
+        // spin
+    }
+}
+
+static PALETTE: [(u8, u8, u8); 16] = [
+    (0, 0, 0),
+    (136, 0, 0),
+    (255, 0, 0),
+    (0, 136, 0),
+    (0, 255, 0),
+    (136, 136, 0),
+    (255, 255, 0),
+    (0, 0, 136),
+    (0, 0, 255),
+    (0, 136, 136),
+    (0, 255, 255),
+    (136, 136, 136),
+    (187, 187, 187),
+    (255, 255, 255),
+    (0, 0, 0),
+    (0, 0, 0),
+];
+
+// End of file

utilities/desktop/src/desktop.raw

@@ -0,0 +1,14 @@
+#![cfg_attr(target_os = "none", no_std)]
+#![cfg_attr(target_os = "none", no_main)]
+
+#[cfg(not(target_os = "none"))]
+fn main() {
+    neotron_sdk::init();
+}
+
+#[no_mangle]
+extern "C" fn neotron_main() -> i32 {
+    desktop::main()
+}
+
+// End of file

utilities/desktop/src/lib.rs

@@ -0,0 +1,12 @@
+[package]
+name = "logo"
+version = "0.1.0"
+edition = "2021"
+license = "MIT OR Apache-2.0"
+authors = ["Jonathan 'theJPster' Pallant <neotron@thejpster.org.uk>"]
+description = "Shows the Windows 95 boot-up logo"
+
+[dependencies]
+neotron-sdk = { workspace = true }
+
+# See workspace for profile settings