Support secondary channel on Matze TKs

AT-Bus can't support second channel but Matze TKs should be able to (because the ROM goes away) Added a detection routine to check if the ROM has gone away.
LIV2 · Nov 18, 2023 · f2dfcb9 · f2dfcb9
1 parent 21bd12f
commit f2dfcb9
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Showing 2 changed files with 52 additions and 18 deletions.
diff --git a/device.h b/device.h
@@ -8,6 +8,7 @@
 #include <stdbool.h>
 #define OAHR_MANUF_ID 5194
 #define BSC_MANUF_ID  2092
+#define A1K_MANUF_ID  2588
 
 #define MAX_UNITS 4
 

diff --git a/driver.c b/driver.c
@@ -189,6 +189,55 @@ static void Cleanup(struct DeviceBase *dev) {
     if (dev->units) FreeMem(dev->units,sizeof(struct IDEUnit) * MAX_UNITS);
 }
 
+/**
+ * detectChannels
+ * 
+ * Detect how many IDE Channels this board has
+ * @param cd Pointer to the ConfigDev struct for this board
+ * @returns number of channels
+*/
+static BYTE detectChannels(struct ConfigDev *cd) {
+
+    if (cd->cd_Rom.er_Manufacturer == BSC_MANUF_ID || cd->cd_Rom.er_Manufacturer == A1K_MANUF_ID) {
+        // On the AT-Bus 2008 (Clone) the ROM is selected on the lower byte when IDE_CS1 is asserted
+        // Not a problem in single channel mode - the drive registers there only use the upper byte
+        // If Status == Alt Status or it's an AT-Bus card then only one channel is supported.
+        //
+        // Check for the ROM Footer
+        // On the AT-Bus 2008 clone it will still be there
+        // On a Matze TK the ROM goes away and the board can do 2 channels
+        ULONG signature = 0;
+        char *romFooter = (char *)cd->cd_BoardAddr + 0xFFF8 + 
+                                    ((cd->cd_Rom.er_InitDiagVec >> 8) & 1); // If the board has an odd offset then add it;
+
+        for (int i=0; i<4; i++) {
+            signature <<= 8;
+            signature |= *romFooter;
+            romFooter += 2;
+        }
+
+        if (signature == 'LIDE') {
+            Info("Channel detection: Saw ROM footer - assuming AT-Bus single channel mode\n");
+            return 1;
+        }
+    }
+
+    // Detect if there are 1 or 2 IDE channels on this board 
+    // 2 channel boards use the CS2 decode for the second channel 
+    UBYTE *status     = cd->cd_BoardAddr + CHANNEL_0 + ata_reg_status;
+    UBYTE *alt_status = cd->cd_BoardAddr + CHANNEL_0 + ata_reg_altStatus;
+
+    UBYTE *drvsel     = cd->cd_BoardAddr + CHANNEL_0 + ata_reg_devHead;
+
+    *drvsel = 0xE0;
+
+    if (*status == *alt_status) {
+        return 1;
+    } else {
+        return 2;
+    }
+}
+
 /**
  * init_device
  *
@@ -261,26 +310,10 @@ struct Library __attribute__((used, saveds)) * init_device(struct ExecBase *SysB
 
     dev->num_boards++;
 
-    // Detect if there are 1 or 2 IDE channels on this board
-    // 2 channel boards use the CS2 decode for the second channel
-    UBYTE channels = 2;
-
-    UBYTE *status     = cd->cd_BoardAddr + CHANNEL_0 + ata_reg_status;
-    UBYTE *alt_status = cd->cd_BoardAddr + CHANNEL_0 + ata_reg_altStatus;
-
-    UBYTE *drvsel     = cd->cd_BoardAddr + CHANNEL_0 + ata_reg_devHead;
-
-    *drvsel = 0xE0;
-
-    // On the AT-Bus 2008 (Clone) the ROM is selected on the lower byte when IDE_CS1 is asserted
-    // Not a problem in single channel mode - the drive registers there only use the upper byte
-    // If Status == Alt Status or it's an AT-Bus card then only one channel is supported.
-    if (*status == *alt_status || cd->cd_Rom.er_Manufacturer == BSC_MANUF_ID) {
-        channels = 1;
-    }
-
+    UBYTE channels = detectChannels(cd);
     Info("Channels: %ld\n",channels);
 
+
     for (BYTE i=0; i < (2 * channels); i++) {
         // Setup each unit structure
         dev->units[i].unitNum           = i;