From 068c907f450d12964026bfc080dfcfda3da21452 Mon Sep 17 00:00:00 2001
From: Terence Boldt <terence@boldt.ca>
Date: Wed, 6 Oct 2021 08:34:18 -0400
Subject: [PATCH] Add support for two drives

---
 RaspberryPi/apple2driver/driver.go            | 69 ++++++++++++++++---
 .../apple2driver/handlers/readBlock.go        | 15 +++-
 .../apple2driver/handlers/writeBlock.go       | 13 +++-
 3 files changed, 84 insertions(+), 13 deletions(-)

diff --git a/RaspberryPi/apple2driver/driver.go b/RaspberryPi/apple2driver/driver.go
index d73a008..2137888 100644
--- a/RaspberryPi/apple2driver/driver.go
+++ b/RaspberryPi/apple2driver/driver.go
@@ -1,8 +1,10 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
+	"path/filepath"
 
 	"github.com/tjboldt/Apple2-IO-RPi/RaspberryPi/apple2driver/a2io"
 	"github.com/tjboldt/Apple2-IO-RPi/RaspberryPi/apple2driver/handlers"
@@ -18,26 +20,20 @@ const SaveFileCommand = 7
 const MenuCommand = 8
 
 func main() {
-	a2io.InitGpio()
+	drive1, drive2 := getDriveFiles()
 
 	fmt.Printf("Starting Apple II RPi...\n")
 
-	fileName := os.Args[1]
-
-	file, err := os.OpenFile(fileName, os.O_RDWR, 0755)
-	if err != nil {
-		fmt.Printf("ERROR: %s", err.Error())
-		os.Exit(1)
-	}
+	a2io.InitGpio()
 
 	for {
 		command, err := a2io.ReadByte()
 		if err == nil {
 			switch command {
 			case ReadBlockCommand:
-				handlers.ReadBlockCommand(file)
+				handlers.ReadBlockCommand(drive1, drive2)
 			case WriteBlockCommand:
-				handlers.WriteBlockCommand(file)
+				handlers.WriteBlockCommand(drive1, drive2)
 			case GetTimeCommand:
 				handlers.GetTimeCommand()
 			case ExecCommand:
@@ -50,3 +46,56 @@ func main() {
 		}
 	}
 }
+
+func getDriveFiles() (*os.File, *os.File) {
+	var drive1Name string
+	var drive2Name string
+
+	execName, _ := os.Executable()
+	path := filepath.Dir(execName)
+	path = filepath.Join(path, "..")
+	path, _ = filepath.EvalSymlinks(path)
+	defaultFileName := filepath.Join(path, "Apple2-IO-RPi.hdv")
+
+	flag.StringVar(&drive1Name, "d1", "", "A ProDOS format drive image for drive 1")
+	flag.StringVar(&drive2Name, "d2", defaultFileName, "A ProDOS format drive image for drive 2 and will be used for drive 1 if drive 1 empty")
+	flag.Parse()
+
+	var drive1 *os.File = nil
+	var drive2 *os.File = nil
+	var err error
+
+	if len(drive1Name) > 0 {
+		fmt.Printf("Opening Drive 1 as: %s\n", drive1Name)
+		drive1, err = os.OpenFile(drive1Name, os.O_RDWR, 0755)
+		if err != nil {
+			fmt.Printf("ERROR: %s", err.Error())
+			os.Exit(1)
+		}
+	}
+
+	if len(drive2Name) > 0 {
+		if drive1 == nil {
+			fmt.Printf("Opening Drive 1 as: %s because Drive 1 was empty\n", drive2Name)
+			drive1, err = os.OpenFile(drive2Name, os.O_RDWR, 0755)
+			if err != nil {
+				fmt.Printf("ERROR: %s", err.Error())
+				os.Exit(1)
+			}
+		} else {
+			fmt.Printf("Opening Drive 2 as: %s\n", drive2Name)
+			drive2, err = os.OpenFile(drive2Name, os.O_RDWR, 0755)
+			if err != nil {
+				fmt.Printf("ERROR: %s", err.Error())
+				os.Exit(1)
+			}
+		}
+	}
+
+	if drive1 == nil {
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	return drive1, drive2
+}
diff --git a/RaspberryPi/apple2driver/handlers/readBlock.go b/RaspberryPi/apple2driver/handlers/readBlock.go
index 5a8c71e..bfcb7a6 100644
--- a/RaspberryPi/apple2driver/handlers/readBlock.go
+++ b/RaspberryPi/apple2driver/handlers/readBlock.go
@@ -7,9 +7,20 @@ import (
 	"github.com/tjboldt/Apple2-IO-RPi/RaspberryPi/apple2driver/a2io"
 )
 
-func ReadBlockCommand(file *os.File) {
+func ReadBlockCommand(drive1 *os.File, drive2 *os.File) {
 	blockLow, _ := a2io.ReadByte()
 	blockHigh, _ := a2io.ReadByte()
+	driveUnit, err := a2io.ReadByte()
+
+	if err != nil {
+		fmt.Printf("Drive unit not sent, assuming older firmware")
+	}
+
+	file := drive1
+
+	if driveUnit >= 8 {
+		file = drive2
+	}
 
 	buffer := make([]byte, 512)
 	var block int64
@@ -19,7 +30,7 @@ func ReadBlockCommand(file *os.File) {
 
 	file.ReadAt(buffer, int64(block)*512)
 
-	err := a2io.WriteBlock(buffer)
+	err = a2io.WriteBlock(buffer)
 	if err == nil {
 		fmt.Printf("Read block completed\n")
 	} else {
diff --git a/RaspberryPi/apple2driver/handlers/writeBlock.go b/RaspberryPi/apple2driver/handlers/writeBlock.go
index 33344d5..0e1b9dc 100644
--- a/RaspberryPi/apple2driver/handlers/writeBlock.go
+++ b/RaspberryPi/apple2driver/handlers/writeBlock.go
@@ -7,9 +7,20 @@ import (
 	"github.com/tjboldt/Apple2-IO-RPi/RaspberryPi/apple2driver/a2io"
 )
 
-func WriteBlockCommand(file *os.File) {
+func WriteBlockCommand(drive1 *os.File, drive2 *os.File) {
 	blockLow, _ := a2io.ReadByte()
 	blockHigh, _ := a2io.ReadByte()
+	driveUnit, err := a2io.ReadByte()
+
+	if err != nil {
+		fmt.Printf("Drive unit not sent, assuming older firmware")
+	}
+
+	file := drive1
+
+	if driveUnit >= 8 {
+		file = drive2
+	}
 
 	buffer := make([]byte, 512)
 	var block int64