Create tool for converting images to compatible console logo files

The tool processes an image and converts it to a logo.Image struct which
can be assigned to a logo-capable console.

src/gopheros/device/video/console/logo/logo.go

@@ -0,0 +1,44 @@
+// Package logo contains logos that can be used with a framebuffer console.
+package logo
+
+import "image/color"
+
+// ConsoleLogo defines the logo used by framebuffer consoles. If set to nil
+// then no logo will be displayed.
+var ConsoleLogo *Image
+
+// Alignment defines the supported horizontal alignments for a console logo.
+type Alignment uint8
+
+const (
+	// AlignLeft aligns the logo to the left side of the console.
+	AlignLeft Alignment = iota
+
+	// AlignCenter aligns the logo to the center of the console.
+	AlignCenter
+
+	// AlignRight aligns the logo to the right side of the console.
+	AlignRight
+)
+
+// Image describes an 8bpp image with
+type Image struct {
+	// The width and height of the logo in pixels.
+	Width  uint32
+	Height uint32
+
+	// Align specifies the horizontal alignment for the logo.
+	Align Alignment
+
+	// TransparentIndex defines a color index that will be treated as
+	// transparent when drawing the logo.
+	TransparentIndex uint8
+
+	// The palette for the logo. The console remaps the palette
+	// entries to the end of its own palette.
+	Palette []color.RGBA
+
+	// The logo data comprises of Width*Height bytes where each byte
+	// represents an index in the logo palette.
+	Data []uint8
+}