Merge pull request #5 from achilleasa/wrap-multiboot-under-a-hal

Begin work on a hardware abstraction layer package

kernel/driver/tty/vt.go

@@ -12,7 +12,7 @@ const (
 type Vt struct {
 	// Go interfaces will not work before we can get memory allocation working.
 	// Till then we need to use concrete types instead.
-	cons *console.Vga
+	cons *console.Ega
 
 	width  uint16
 	height uint16
@@ -22,7 +22,9 @@ type Vt struct {
 	curAttr console.Attr
 }
 
-func (t *Vt) Init(cons *console.Vga) {
+// AttachTo links the terminal with the specified console device and updates
+// the terminal's dimensions to match the ones reported by the attached device.
+func (t *Vt) AttachTo(cons *console.Ega) {
 	t.cons = cons
 	t.width, t.height = cons.Dimensions()
 	t.curX = 0
@@ -30,30 +32,20 @@ func (t *Vt) Init(cons *console.Vga) {
 
 	// Default to lightgrey on black text.
 	t.curAttr = makeAttr(defaultFg, defaultBg)
-
 }
 
 // Clear clears the terminal.
 func (t *Vt) Clear() {
-	t.cons.Lock()
-	defer t.cons.Unlock()
-
 	t.clear()
 }
 
 // Position returns the current cursor position (x, y).
 func (t *Vt) Position() (uint16, uint16) {
-	t.cons.Lock()
-	defer t.cons.Unlock()
-
 	return t.curX, t.curY
 }
 
 // SetPosition sets the current cursor position to (x,y).
 func (t *Vt) SetPosition(x, y uint16) {
-	t.cons.Lock()
-	defer t.cons.Unlock()
-
 	if x >= t.width {
 		x = t.width - 1
 	}
@@ -67,9 +59,6 @@ func (t *Vt) SetPosition(x, y uint16) {
 
 // Write implements io.Writer.
 func (t *Vt) Write(data []byte) (int, error) {
-	t.cons.Lock()
-	defer t.cons.Unlock()
-
 	attr := t.curAttr
 	for _, b := range data {
 		switch b {

kernel/driver/tty/vt_test.go

@@ -2,6 +2,7 @@ package tty
 
 import (
 	"testing"
+	"unsafe"
 
 	"github.com/achilleasa/gopher-os/kernel/driver/video/console"
 )
@@ -18,11 +19,12 @@ func TestVtPosition(t *testing.T) {
 		{100, 100, 79, 24},
 	}
 
-	var cons console.Vga
+	fb := make([]uint16, 80*25)
-	cons.Init()
+	var cons console.Ega
+	cons.Init(80, 25, uintptr(unsafe.Pointer(&fb[0])))
 
 	var vt Vt
-	vt.Init(&cons)
+	vt.AttachTo(&cons)
 
 	for specIndex, spec := range specs {
 		vt.SetPosition(spec.inX, spec.inY)
@@ -34,12 +36,11 @@ func TestVtPosition(t *testing.T) {
 
 func TestWrite(t *testing.T) {
 	fb := make([]uint16, 80*25)
-	cons := &console.Vga{}
+	var cons console.Ega
-	cons.OverrideFb(fb)
+	cons.Init(80, 25, uintptr(unsafe.Pointer(&fb[0])))
-	cons.Init()
 
 	var vt Vt
-	vt.Init(cons)
+	vt.AttachTo(&cons)
 
 	vt.Clear()
 	vt.SetPosition(0, 1)

kernel/driver/video/console/console.go

@@ -1,7 +1,5 @@
 package console
 
-import "sync"
-
 // Attr defines a color attribute.
 type Attr uint16
 
@@ -36,8 +34,6 @@ const (
 
 // The Console interface is implemented by objects that can function as physical consoles.
 type Console interface {
-	sync.Locker
-
 	// Dimensions returns the width and height of the console in characters.
 	Dimensions() (uint16, uint16)
 

kernel/driver/video/console/ega.go

@@ -2,7 +2,6 @@ package console
 
 import (
 	"reflect"
-	"sync"
 	"unsafe"
 )
 
@@ -11,13 +10,11 @@ const (
 	clearChar  = byte(' ')
 )
 
-// Vga implements an EGA-compatible text console. At the moment, it uses the
+// Ega implements an EGA-compatible text console. At the moment, it uses the
 // ega console physical address as its outpucons. After implementing a memory
 // allocator, each console will use its own framebuffer while the active console
 // will periodically sync its internal buffer with the physical screen buffer.
-type Vga struct {
+type Ega struct {
-	sync.Mutex
-
 	width  uint16
 	height uint16
 
@@ -25,32 +22,19 @@ type Vga struct {
 }
 
 // Init sets up the console.
-func (cons *Vga) Init() {
+func (cons *Ega) Init(width, height uint16, fbPhysAddr uintptr) {
-	cons.width = 80
+	cons.width = width
-	cons.height = 25
+	cons.height = height
-
-	// Set up our frame buffer object by creating a fake slice object pointing
-	// to the physical address of the screen buffer.
-	if cons.fb != nil {
-		return
-	}
 
 	cons.fb = *(*[]uint16)(unsafe.Pointer(&reflect.SliceHeader{
 		Len:  int(cons.width * cons.height),
 		Cap:  int(cons.width * cons.height),
-		Data: uintptr(0xB8000),
+		Data: fbPhysAddr,
 	}))
 }
 
-// OverrideFb overrides the console framebuffer slice with the supplied slice.
-// This is a temporary function used by tests that will be removed once we can work
-// with interfaces.
-func (cons *Vga) OverrideFb(fb []uint16) {
-	cons.fb = fb
-}
-
 // Clear clears the specified rectangular region
-func (cons *Vga) Clear(x, y, width, height uint16) {
+func (cons *Ega) Clear(x, y, width, height uint16) {
 	var (
 		attr                 = uint16((clearColor << 4) | clearColor)
 		clr                  = attr | uint16(clearChar)
@@ -81,12 +65,12 @@ func (cons *Vga) Clear(x, y, width, height uint16) {
 }
 
 // Dimensions returns the console width and height in characters.
-func (cons *Vga) Dimensions() (uint16, uint16) {
+func (cons *Ega) Dimensions() (uint16, uint16) {
 	return cons.width, cons.height
 }
 
 // Scroll a particular number of lines to the specified direction.
-func (cons *Vga) Scroll(dir ScrollDir, lines uint16) {
+func (cons *Ega) Scroll(dir ScrollDir, lines uint16) {
 	if lines == 0 || lines > cons.height {
 		return
 	}
@@ -107,7 +91,7 @@ func (cons *Vga) Scroll(dir ScrollDir, lines uint16) {
 }
 
 // Write a char to the specified location.
-func (cons *Vga) Write(ch byte, attr Attr, x, y uint16) {
+func (cons *Ega) Write(ch byte, attr Attr, x, y uint16) {
 	if x >= cons.width || y >= cons.height {
 		return
 	}

kernel/driver/video/console/ega_test.go

@@ -1,10 +1,13 @@
 package console
 
-import "testing"
+import (
+	"testing"
+	"unsafe"
+)
 
-func TestVgaInit(t *testing.T) {
+func TestEgaInit(t *testing.T) {
-	var cons Vga
+	var cons Ega
-	cons.Init()
+	cons.Init(80, 25, 0xB8000)
 
 	var expWidth uint16 = 80
 	var expHeight uint16 = 25
@@ -14,7 +17,7 @@ func TestVgaInit(t *testing.T) {
 	}
 }
 
-func TestVgaClear(t *testing.T) {
+func TestEgaClear(t *testing.T) {
 	specs := []struct {
 		// Input rect
 		x, y, w, h uint16
@@ -48,8 +51,9 @@ func TestVgaClear(t *testing.T) {
 		},
 	}
 
-	var cons = Vga{fb: make([]uint16, 80*25)}
+	fb := make([]uint16, 80*25)
-	cons.Init()
+	var cons Ega
+	cons.Init(80, 25, uintptr(unsafe.Pointer(&fb[0])))
 
 	testPat := uint16(0xDEAD)
 	clearPat := (uint16(clearColor) << 8) | uint16(clearChar)
@@ -58,7 +62,7 @@ nextSpec:
 	for specIndex, spec := range specs {
 		// Fill FB with test pattern
 		for i := 0; i < len(cons.fb); i++ {
-			cons.fb[i] = testPat
+			fb[i] = testPat
 		}
 
 		cons.Clear(spec.x, spec.y, spec.w, spec.h)
@@ -66,7 +70,7 @@ nextSpec:
 		var x, y uint16
 		for y = 0; y < cons.height; y++ {
 			for x = 0; x < cons.width; x++ {
-				fbVal := cons.fb[(y*cons.width)+x]
+				fbVal := fb[(y*cons.width)+x]
 
 				if x < spec.expX || y < spec.expY || x >= spec.expX+spec.expW || y >= spec.expY+spec.expH {
 					if fbVal != testPat {
@@ -84,15 +88,16 @@ nextSpec:
 	}
 }
 
-func TestVgaScrollUp(t *testing.T) {
+func TestEgaScrollUp(t *testing.T) {
 	specs := []uint16{
 		0,
 		1,
 		2,
 	}
 
-	var cons = Vga{fb: make([]uint16, 80*25)}
+	fb := make([]uint16, 80*25)
-	cons.Init()
+	var cons Ega
+	cons.Init(80, 25, uintptr(unsafe.Pointer(&fb[0])))
 
 nextSpec:
 	for specIndex, lines := range specs {
@@ -100,7 +105,7 @@ nextSpec:
 		var x, y, index uint16
 		for y = 0; y < cons.height; y++ {
 			for x = 0; x < cons.width; x++ {
-				cons.fb[index] = (y << 8) | x
+				fb[index] = (y << 8) | x
 				index++
 			}
 		}
@@ -112,7 +117,7 @@ nextSpec:
 		for y = 0; y < cons.height-lines; y++ {
 			for x = 0; x < cons.width; x++ {
 				expVal := ((y + lines) << 8) | x
-				if cons.fb[index] != expVal {
+				if fb[index] != expVal {
 					t.Errorf("[spec %d] expected value at (%d, %d) to be %d; got %d", specIndex, x, y, expVal, cons.fb[index])
 					continue nextSpec
 				}
@@ -122,15 +127,16 @@ nextSpec:
 	}
 }
 
-func TestVgaScrollDown(t *testing.T) {
+func TestEgaScrollDown(t *testing.T) {
 	specs := []uint16{
 		0,
 		1,
 		2,
 	}
 
-	var cons = Vga{fb: make([]uint16, 80*25)}
+	fb := make([]uint16, 80*25)
-	cons.Init()
+	var cons Ega
+	cons.Init(80, 25, uintptr(unsafe.Pointer(&fb[0])))
 
 nextSpec:
 	for specIndex, lines := range specs {
@@ -138,7 +144,7 @@ nextSpec:
 		var x, y, index uint16
 		for y = 0; y < cons.height; y++ {
 			for x = 0; x < cons.width; x++ {
-				cons.fb[index] = (y << 8) | x
+				fb[index] = (y << 8) | x
 				index++
 			}
 		}
@@ -150,7 +156,7 @@ nextSpec:
 		for y = lines; y < cons.height-lines; y++ {
 			for x = 0; x < cons.width; x++ {
 				expVal := ((y - lines) << 8) | x
-				if cons.fb[index] != expVal {
+				if fb[index] != expVal {
 					t.Errorf("[spec %d] expected value at (%d, %d) to be %d; got %d", specIndex, x, y, expVal, cons.fb[index])
 					continue nextSpec
 				}
@@ -160,9 +166,10 @@ nextSpec:
 	}
 }
 
-func TestVgaWriteWithOffScreenCoords(t *testing.T) {
+func TestEgaWriteWithOffScreenCoords(t *testing.T) {
-	var cons = Vga{fb: make([]uint16, 80*25)}
+	fb := make([]uint16, 80*25)
-	cons.Init()
+	var cons Ega
+	cons.Init(80, 25, uintptr(unsafe.Pointer(&fb[0])))
 
 	specs := []struct {
 		x, y uint16
@@ -176,13 +183,13 @@ func TestVgaWriteWithOffScreenCoords(t *testing.T) {
 nextSpec:
 	for specIndex, spec := range specs {
 		for i := 0; i < len(cons.fb); i++ {
-			cons.fb[i] = 0
+			fb[i] = 0
 		}
 
 		cons.Write('!', Red, spec.x, spec.y)
 
 		for i := 0; i < len(cons.fb); i++ {
-			if got := cons.fb[i]; got != 0 {
+			if got := fb[i]; got != 0 {
 				t.Errorf("[spec %d] expected Write() with off-screen coords to be a no-op", specIndex)
 				continue nextSpec
 			}
@@ -190,27 +197,16 @@ nextSpec:
 	}
 }
 
-func TestVgaWrite(t *testing.T) {
+func TestEgaWrite(t *testing.T) {
-	var cons = Vga{fb: make([]uint16, 80*25)}
+	fb := make([]uint16, 80*25)
-	cons.Init()
+	var cons Ega
+	cons.Init(80, 25, uintptr(unsafe.Pointer(&fb[0])))
 
 	attr := (Black << 4) | Red
 	cons.Write('!', attr, 0, 0)
 
 	expVal := uint16(attr<<8) | uint16('!')
-	if got := cons.fb[0]; got != expVal {
+	if got := fb[0]; got != expVal {
 		t.Errorf("expected call to Write() to set fb[0] to %d; got %d", expVal, got)
 	}
 }
-
-func TestVgaOverrideFb(t *testing.T) {
-	var cons = Vga{}
-	cons.Init()
-
-	fb := []uint16{}
-	cons.OverrideFb(fb)
-
-	if len(cons.fb) != len(fb) {
-		t.Fatalf("expected calling OverrideFb to change the framebuffer for the console")
-	}
-}

kernel/hal/hal.go

@@ -0,0 +1,21 @@
+package hal
+
+import (
+	"github.com/achilleasa/gopher-os/kernel/driver/tty"
+	"github.com/achilleasa/gopher-os/kernel/driver/video/console"
+	"github.com/achilleasa/gopher-os/kernel/hal/multiboot"
+)
+
+var (
+	egaConsole     = &console.Ega{}
+	ActiveTerminal = &tty.Vt{}
+)
+
+// InitTerminal provides a basic terminal to allow the kernel to emit some output
+// till everything is properly setup
+func InitTerminal() {
+	fbInfo := multiboot.GetFramebufferInfo()
+
+	egaConsole.Init(uint16(fbInfo.Width), uint16(fbInfo.Height), uintptr(fbInfo.PhysAddr))
+	ActiveTerminal.AttachTo(egaConsole)
+}

kernel/kmain.go

@@ -3,7 +3,8 @@ package kernel
 import (
 	_ "unsafe" // required for go:linkname
 
-	"github.com/achilleasa/gopher-os/kernel/multiboot"
+	"github.com/achilleasa/gopher-os/kernel/hal"
+	"github.com/achilleasa/gopher-os/kernel/hal/multiboot"
 )
 
 // Kmain is the only Go symbol that is visible (exported) from the rt0 initialization
@@ -19,4 +20,8 @@ import (
 //go:noinline
 func Kmain(multibootInfoPtr uint32) {
 	multiboot.SetInfoPtr(uintptr(multibootInfoPtr))
+
+	// Initialize and clear the terminal
+	hal.InitTerminal()
+	hal.ActiveTerminal.Clear()
 }