1 files changed, 64 insertions, 0 deletions
diff --git a/baremetal/500text-screen.mu b/baremetal/500text-screen.mu
new file mode 100644
index 00000000..525ddb03
--- /dev/null
+++ b/baremetal/500text-screen.mu
@@ -0,0 +1,64 @@
+# Screen primitives for character-oriented output.
+#
+# Unlike the top-level, this text mode has no scrolling.
+
+fn draw-grapheme screen: (addr screen), g: grapheme, x: int, y: int, color: int {
+  {
+    compare screen, 0
+    break-if-!=
+    draw-grapheme-on-real-screen g, x, y, color
+    return
+  }
+  # TODO: fake screen
+}
+
+fn cursor-position screen: (addr screen) -> _/eax: int, _/ecx: int {
+  {
+    compare screen, 0
+    break-if-!=
+    var x/eax: int <- copy 0
+    var y/ecx: int <- copy 0
+    x, y <- cursor-position-on-real-screen
+    return x, y
+  }
+  # TODO: fake screen
+  return 0, 0
+}
+
+fn set-cursor-position screen: (addr screen), x: int, y: int {
+  {
+    compare screen, 0
+    break-if-!=
+    set-cursor-position-on-real-screen x, y
+    return
+  }
+  # TODO: fake screen
+}
+
+fn clear-screen screen: (addr screen) {
+  {
+    compare screen, 0
+    break-if-!=
+    clear-real-screen
+    return
+  }
+  # TODO: fake screen
+}
+
+fn clear-real-screen {
+  var y/eax: int <- copy 0
+  {
+    compare y, 0x300  # 768
+    break-if->=
+    var x/edx: int <- copy 0
+    {
+      compare x, 0x400  # 1024
+      break-if->=
+      pixel-on-real-screen x, y, 0  # black
+      x <- increment
+      loop
+    }
+    y <- increment
+    loop
+  }
+}