Store a raw pointer in Display for the framebuffer

src/devices/graphical_debug/debug.rs

@@ -65,12 +65,7 @@ impl DebugDisplay {
     /// Draw a character
     fn char(&mut self, x: usize, y: usize, character: char, color: u32) {
         if x + 8 <= self.display.width && y + 16 <= self.display.height {
-            let mut dst = unsafe {
-                self.display
-                    .data_mut()
-                    .as_mut_ptr()
-                    .add(y * self.display.stride + x)
-            };
+            let mut dst = unsafe { self.display.data_mut().add(y * self.display.stride + x) };
 
             let font_i = 16 * (character as usize);
             if font_i + 16 <= FONT.len() {
@@ -94,7 +89,7 @@ impl DebugDisplay {
         let offset = cmp::min(self.display.height, lines) * self.display.stride;
         let size = (self.display.stride * self.display.height) - offset;
         unsafe {
-            let ptr = self.display.data_mut().as_mut_ptr();
+            let ptr = self.display.data_mut();
             ptr::copy(ptr.add(offset), ptr, size);
             ptr::write_bytes(ptr.add(size), 0, offset);
         }

src/devices/graphical_debug/display.rs

@@ -6,10 +6,12 @@ pub(super) struct Display {
     pub(super) width: usize,
     pub(super) height: usize,
     pub(super) stride: usize,
-    onscreen: &'static mut [u32],
+    onscreen_ptr: *mut u32,
     offscreen: Option<Box<[u32]>>,
 }
 
+unsafe impl Send for Display {}
+
 impl Display {
     pub(super) fn new(
         width: usize,
@@ -17,28 +19,28 @@ impl Display {
         stride: usize,
         onscreen_ptr: *mut u32,
     ) -> Display {
-        let size = stride * height;
-        let onscreen = unsafe {
-            ptr::write_bytes(onscreen_ptr, 0, size);
-            slice::from_raw_parts_mut(onscreen_ptr, size)
-        };
+        unsafe {
+            ptr::write_bytes(onscreen_ptr, 0, stride * height);
+        }
         Display {
             width,
             height,
             stride,
-            onscreen,
+            onscreen_ptr,
             offscreen: None,
         }
     }
 
     pub(super) fn heap_init(&mut self) {
-        self.offscreen = Some(self.onscreen.to_vec().into_boxed_slice());
+        let onscreen =
+            unsafe { slice::from_raw_parts(self.onscreen_ptr, self.stride * self.height) };
+        self.offscreen = Some(onscreen.to_vec().into_boxed_slice());
     }
 
-    pub(super) fn data_mut(&mut self) -> &mut [u32] {
+    pub(super) fn data_mut(&mut self) -> *mut u32 {
         match &mut self.offscreen {
-            Some(offscreen) => offscreen,
-            None => self.onscreen,
+            Some(offscreen) => offscreen.as_mut_ptr(),
+            None => self.onscreen_ptr,
         }
     }
 
@@ -47,7 +49,11 @@ impl Display {
         if let Some(offscreen) = &self.offscreen {
             let mut offset = y * self.stride + x;
             while h > 0 {
-                self.onscreen[offset..offset + w].copy_from_slice(&offscreen[offset..offset + w]);
+                ptr::copy(
+                    offscreen.as_ptr().add(offset),
+                    self.onscreen_ptr.add(offset),
+                    w,
+                );
                 offset += self.stride;
                 h -= 1;
             }