Detect hw and wire active console and TTY

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

@@ -0,0 +1,16 @@
+package console
+
+import "gopheros/device"
+import "gopheros/kernel/hal/multiboot"
+
+var (
+	getFramebufferInfoFn = multiboot.GetFramebufferInfo
+)
+
+// HWProbes returns a slice of device.ProbeFn that can be used by the hal
+// package to probe for console device hardware.
+func HWProbes() []device.ProbeFn {
+	return []device.ProbeFn{
+		probeForVgaTextConsole,
+	}
+}

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

@@ -1,8 +1,10 @@
 package console
 
 import (
+	"gopheros/device"
 	"gopheros/kernel"
 	"gopheros/kernel/cpu"
+	"gopheros/kernel/hal/multiboot"
 	"image/color"
 	"reflect"
 	"unsafe"
@@ -196,3 +198,15 @@ func (cons *VgaTextConsole) DriverVersion() (uint16, uint16, uint16) {
 
 // DriverInit initializes this driver.
 func (cons *VgaTextConsole) DriverInit() *kernel.Error { return nil }
+
+// probeForVgaTextConsole checks for the presence of a vga text console.
+func probeForVgaTextConsole() device.Driver {
+	var drv device.Driver
+
+	fbInfo := getFramebufferInfoFn()
+	if fbInfo.Type == multiboot.FramebufferTypeEGA {
+		drv = NewVgaTextConsole(uint16(fbInfo.Width), uint16(fbInfo.Height), uintptr(fbInfo.PhysAddr))
+	}
+
+	return drv
+}

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

@@ -3,7 +3,9 @@ package console
 import (
 	"gopheros/device"
 	"gopheros/kernel/cpu"
+	"gopheros/kernel/hal/multiboot"
 	"image/color"
+	"reflect"
 	"testing"
 	"unsafe"
 )
@@ -318,3 +320,39 @@ func TestVgaTextDriverInterface(t *testing.T) {
 		t.Fatal("DriverVersion() returned an invalid version number")
 	}
 }
+
+func TestVgaTextProbe(t *testing.T) {
+	defer func() {
+		getFramebufferInfoFn = multiboot.GetFramebufferInfo
+	}()
+
+	var (
+		expProbePtr = reflect.ValueOf(probeForVgaTextConsole).Pointer()
+		foundProbe  bool
+	)
+
+	for _, probeFn := range HWProbes() {
+		if reflect.ValueOf(probeFn).Pointer() == expProbePtr {
+			foundProbe = true
+			break
+		}
+	}
+
+	if !foundProbe {
+		t.Fatal("expected probeForVgaTextConsole to be part of the probes returned by HWProbes")
+	}
+
+	getFramebufferInfoFn = func() *multiboot.FramebufferInfo {
+		return &multiboot.FramebufferInfo{
+			Width:    80,
+			Height:   25,
+			Pitch:    160,
+			PhysAddr: 0xb80000,
+			Type:     multiboot.FramebufferTypeEGA,
+		}
+	}
+
+	if drv := probeForVgaTextConsole(); drv == nil {
+		t.Fatal("expected probeForVgaTextConsole to return a driver")
+	}
+}