Select appropriate font for console devices with font support

The hal package automatically selects the best font from the list of
available fonts based on the console dimensions and the font priorities. The font
selection can be overriden by passing the "consoleFont" boot commandline
parameter to the kernel (e.g. consoleFont=terminus8x16)

src/gopheros/kernel/hal/hal.go

@@ -5,6 +5,8 @@ import (
 	"gopheros/device"
 	"gopheros/device/tty"
 	"gopheros/device/video/console"
+	"gopheros/device/video/console/font"
+	"gopheros/kernel/hal/multiboot"
 	"gopheros/kernel/kfmt"
 )
 
@@ -30,6 +32,28 @@ func DetectHardware() {
 	consoles := probe(console.ProbeFuncs)
 	if len(consoles) != 0 {
 		devices.activeConsole = consoles[0].(console.Device)
+
+		if fontSetter, ok := (devices.activeConsole).(console.FontSetter); ok {
+			consW, consH := devices.activeConsole.Dimensions(console.Pixels)
+
+			// Check boot cmdline for a font request
+			var selFont *font.Font
+			for k, v := range multiboot.GetBootCmdLine() {
+				if k != "consoleFont" {
+					continue
+				}
+
+				if selFont = font.FindByName(v); selFont != nil {
+					break
+				}
+			}
+
+			if selFont == nil {
+				selFont = font.BestFit(consW, consH)
+			}
+
+			fontSetter.SetFont(selFont)
+		}
 	}
 
 	ttys := probe(tty.ProbeFuncs)