debugger: crank the debug port up to 1.3Mbps

With this, full memory read-out takes ~1s.

debugger/main.go

@@ -14,7 +14,7 @@ func main() {
 	}
 	defer dbg.Close()
 
-	mem := memory.New(dbg, 4*1024)
+	mem := memory.New(dbg, 128*1024)
 
 	if err := UI(mem); err != nil {
 		log.Fatal(err)

debugger/serial/serial.go

@@ -13,7 +13,7 @@ import (
 
 const (
 	portDev      = "/dev/ttyUSB0"
-	portSpeed    = 115_200
+	portSpeed    = 1_382_400 // 1.3Mbps
 	maxAddr      = 1 << 17
 	pingResponse = 0xEA
 	readTimeout  = 2 * time.Second
@@ -26,7 +26,7 @@ type Serial struct {
 
 func Open() (*Serial, error) {
 	mode := &serial.Mode{
-		BaudRate: 115_200,
+		BaudRate: portSpeed,
 	}
 	port, err := serial.Open(portDev, mode)
 	if err != nil {
@@ -38,6 +38,7 @@ func Open() (*Serial, error) {
 		port.Close()
 		return nil, err
 	}
+
 	port.SetReadTimeout(readTimeout)
 	if _, err := io.ReadFull(port, packet[:1]); err != nil {
 		port.Close()
@@ -80,7 +81,7 @@ func encode(cmd int, addr int, data byte) [4]byte {
 func (d *Serial) readSlow(bs []byte, off int64) (int, error) {
 	d.portMu.Lock()
 	defer d.portMu.Unlock()
-	if off+int64(len(bs)) >= maxAddr {
+	if off+int64(len(bs)) > maxAddr {
 		return 0, errors.New("OOB read")
 	}
 	for i := range bs {
@@ -100,7 +101,7 @@ func (d *Serial) readSlow(bs []byte, off int64) (int, error) {
 func (d *Serial) readBurst(bs []byte, off int64) (int, error) {
 	d.portMu.Lock()
 	defer d.portMu.Unlock()
-	if off+int64(len(bs)) >= maxAddr {
+	if off+int64(len(bs)) > maxAddr {
 		return 0, errors.New("OOB read")
 	}
 	for i := 0; i < len(bs); i += 255 {
@@ -125,7 +126,7 @@ func (d *Serial) ReadAt(bs []byte, off int64) (int, error) {
 func (d *Serial) WriteAt(bs []byte, off int64) (int, error) {
 	d.portMu.Lock()
 	defer d.portMu.Unlock()
-	if off+int64(len(bs)) >= maxAddr {
+	if off+int64(len(bs)) > maxAddr {
 		return 0, errors.New("OOB write")
 	}
 	for i, v := range bs {

debugger/ui.go

@@ -82,8 +82,8 @@ func (m debugger) readFullMemory() tea.Cmd {
 
 func (m debugger) readFullMemoryCmds() []tea.Cmd {
 	var ret []tea.Cmd
-	for i := 0; i < m.mem.Len(); i += 128 {
+	for i := 0; i < m.mem.Len(); i += 32 * 1024 {
-		ret = append(ret, m.readMemory(i, 128))
+		ret = append(ret, m.readMemory(i, 32*1024))
 	}
 	return ret
 }

hardware/ulx3s/Top.bsv

@@ -46,7 +46,7 @@ module mkTop(Top);
 
    ////////////
    // Debugging
-   let debugger <- mkUARTDebugger(25_000_000, 115_200, mem.debugger);
+   let debugger <- mkUARTDebugger(25_000_000, 1_382_400, mem.debugger);
    let blinky <- mkBlinky(25_000_000);
 
    ////////////