From f912d9230eaa0c54a09d2085a400b112b080613a Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Sun, 7 Oct 2018 23:59:00 -0500
Subject: [PATCH] Do actual auto-detection of DOS-order versus ProDOS-order.

The basic approach is just to see if GS/OS can understand the disk (i.e. if a VolumeGS call succeeds), and if not switch the order. We currently start with ProDOS order, then switch to DOS order if necessary. This is only currently done for 140k images.
---
 driver.c      | 33 +++++++++++++++++++++++++--------
 driver.h      |  4 +++-
 netdiskinit.c | 34 +++++++++++++++++++++++++++++++++-
 3 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/driver.c b/driver.c
index 95d454b..a16280f 100644
--- a/driver.c
+++ b/driver.c
@@ -35,6 +35,7 @@ static Word DoMountURL(struct GSOSDP *dp);
 static Word DoRead(struct GSOSDP *dp);
 static Word DoStatus(struct GSOSDP *dp);
 static Word DoEject(struct GSOSDP *dp);
+static Word DoSwitchToDOSOrder(struct GSOSDP *dp);
 static Word DoShutdown(struct GSOSDP *dp);
 
 void InitDIBs(void) {
@@ -176,7 +177,11 @@ Word DriverDispatch(Word callNum, struct GSOSDP *dp) {
             break;
             
         case Mount_URL:
-            DoMountURL(dp);
+            retVal = DoMountURL(dp);
+            break;
+        
+        case Switch_To_DOS_Order:
+            retVal = DoSwitchToDOSOrder(dp);
             break;
         
         default:
@@ -318,13 +323,6 @@ static Word DoMountURL(struct GSOSDP *dp) {
         sess->dataLength = sess->totalLength;
     }
     
-    // TODO remove this hack in favor of better format detection
-    if (mountURLRec->format == formatAutoDetect) {
-        if (sess->dataLength == DISK_II_DISK_SIZE) {
-            mountURLRec->format = formatDOSOrder;
-        }
-    }
-    
     if (mountURLRec->format == formatDOSOrder) {
         if (sess->dataLength % TRACK_SIZE != 0) {
             dp->transferCount = 0;
@@ -538,6 +536,25 @@ static Word DoEject(struct GSOSDP *dp) {
     return 0;
 }
 
+static Word DoSwitchToDOSOrder(struct GSOSDP *dp) {
+    dp->transferCount = 0;
+
+    if (dp->dibPointer == NULL)
+        return drvrBadParm;
+
+    Session *sess = (Session*)dp->dibPointer->extendedDIBPtr;
+    if (sess == NULL)
+        return drvrBadParm;
+
+    if (sess->dataLength % TRACK_SIZE != 0)
+        return drvrBadParm;
+
+    sess->dosOrder = TRUE;
+    SetDiskSw();
+    
+    return 0;
+}
+
 static Word DoShutdown(struct GSOSDP *dp) {
     /*
      * We don't actually end the session here, because this may just be
diff --git a/driver.h b/driver.h
index 9d8c727..9f70e5a 100644
--- a/driver.h
+++ b/driver.h
@@ -68,8 +68,10 @@ struct GSOSDP {
 #define Get_Format_Options    0x0003
 #define Get_Partition_Map     0x0004
 
-/* Custom Driver_Control subcall */
+/* Custom Driver_Control subcalls */
 #define Mount_URL 0x8080
+#define Switch_To_DOS_Order 0x8081
+
 
 /* Status list record for Get_DeviceStatus */
 typedef struct DeviceStatusRec {
diff --git a/netdiskinit.c b/netdiskinit.c
index 3e54807..6c002ea 100644
--- a/netdiskinit.c
+++ b/netdiskinit.c
@@ -40,6 +40,9 @@ static void ejectAll(void);
 
 #define JML 0x5C
 
+/* Custom DControl code for switching to DOS order */
+#define SwitchToDOSOrder 0x8081
+
 
 static void setUnloadFlag(void) {
     if (unloadFlagPtr != NULL && *unloadFlagPtr == 0)
@@ -131,8 +134,37 @@ static void doMountURL(struct MountURLRec *mountURLRec) {
         controlRec.devNum = devNum;
         DControl(&controlRec);
         
-        if (mountURLRec->result != DISK_ALREADY_MOUNTED)
+        if (mountURLRec->result == OPERATION_SUCCESSFUL) {
+            if (mountURLRec->format != formatAutoDetect)
+                return;
+
+            /* Current operating assumption is that it's ProDOS-order (raw) */
+            mountURLRec->format = formatRaw;
+
+            /*
+             * Auto-detect DOS vs ProDOS order by seeing if
+             * GS/OS can recognize the volume.
+             */
+            static ResultBuf32 devName = {35};
+            static DInfoRecGS dInfoRec = {2, 0, &devName};
+            dInfoRec.devNum = devNum;
+            DInfo(&dInfoRec);
+            if (toolerror())
+                return;
+        
+            static ResultBuf255 volumeName = {255+2+2};
+            static VolumeRecGS volumeRec = {2, &devName.bufString, &volumeName};
+            Volume(&volumeRec);
+            
+            if (toolerror() == unknownVol) {
+                controlRec.code = SwitchToDOSOrder;
+                DControl(&controlRec);
+            }
+            
             return;
+        } else if (mountURLRec->result != DISK_ALREADY_MOUNTED) {
+            return;
+        }
     }
     
     mountURLRec->result = NO_DIBS_AVAILABLE;