Add NCR 53C90 stub.

devices/common/scsi/ncr53c94.cpp

@@ -0,0 +1,38 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-21 divingkatae and maximum
+                      (theweirdo)     spatium
+
+(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+/** @file NCR 53C94 SCSI controller emulation. */
+
+#include "ncr53c94.h"
+#include <loguru.hpp>
+
+#include <cinttypes>
+
+uint8_t Ncr53C94::read(uint8_t reg_offset)
+{
+    LOG_F(9, "NCR53C94: reading from register %d", reg_offset);
+    return 0;
+}
+
+void Ncr53C94::write(uint8_t reg_offset, uint8_t value)
+{
+    LOG_F(INFO, "NCR53C94: writing 0x%X to %d register", value, reg_offset);
+}

devices/common/scsi/ncr53c94.h

@@ -0,0 +1,89 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-21 divingkatae and maximum
+                      (theweirdo)     spatium
+
+(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+/** @file NCR 53C94 SCSI controller definitions. */
+
+/* NOTE: Power Macintosh computers don't have a real NCR 53C94 chip.
+   The corresponding functionality is provided by the 53C94 compatible
+   cell in the custom Curio IC (Am79C950).
+*/
+
+#ifndef NCR53C94_H
+#define NCR53C94_H
+
+#include <cinttypes>
+
+/** NCR 53C94 read registers */
+namespace Read {
+    enum Reg53C94 : uint8_t {
+        Xfer_Cnt_LSB = 0,
+        Xfer_Cnt_MSB = 1,
+        FIFO         = 2,
+        Command      = 3,
+        Status       = 4,
+        Interrupt    = 5,
+        Seq_Step     = 6,
+        FIFO_Flags   = 7,
+        Config_1     = 8,
+        Config_2     = 0xB,
+        Config_3     = 0xC,
+        Config_4     = 0xD, // Curio extension?
+        Xfer_Cnt_Hi  = 0xE, // Curio extension?
+        DMA          = 0xF, // Curio extension?
+    };
+};
+
+/** NCR 53C94 write registers */
+namespace Write {
+    enum Reg53C94 : uint8_t {
+        Xfer_Cnt_LSB = 0,
+        Xfer_Cnt_MSB = 1,
+        FIFO         = 2,
+        Command      = 3,
+        Dest_Bus_ID  = 4,
+        Sel_Timeout  = 5,
+        Synch_Period = 6,
+        Synch_Offset = 7,
+        Config_1     = 8,
+        Clk_Conv_Fac = 9,
+        Test_Mode    = 0xA,
+        Config_2     = 0xB,
+        Config_3     = 0xC,
+        Config_4     = 0xD, // Curio extension?
+        Chip_ID      = 0xE, // Curio extension?
+        DMA          = 0xF, // Curio extension?
+    };
+};
+
+class Ncr53C94 {
+public:
+    Ncr53C94()  = default;
+    ~Ncr53C94() = default;
+
+    // NCR 53C94 registers access
+    uint8_t read(uint8_t reg_offset);
+    void   write(uint8_t reg_offset, uint8_t value);
+
+private:
+    uint8_t chip_id;
+};
+
+#endif // NCR53C94_H

devices/ioctrl/amic.cpp

@@ -25,6 +25,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
 #include <cpu/ppc/ppcmmu.h>
+#include <devices/common/scsi/ncr53c94.h>
 #include <devices/common/viacuda.h>
 #include <devices/ethernet/mace.h>
 #include <devices/ioctrl/amic.h>
@@ -49,6 +50,7 @@ AMIC::AMIC()
         LOG_F(ERROR, "Couldn't register AMIC registers!");
     }
 
+    this->scsi    = std::unique_ptr<Ncr53C94> (new Ncr53C94());
     this->escc    = std::unique_ptr<EsccController> (new EsccController());
     this->mace    = std::unique_ptr<MaceController> (new MaceController(MACE_ID));
     this->viacuda = std::unique_ptr<ViaCuda> (new ViaCuda());
@@ -81,8 +83,7 @@ uint32_t AMIC::read(uint32_t reg_start, uint32_t offset, int size)
     case 0xA: // MACE registers
         return this->mace->read((offset >> 4) & 0xF);
     case 0x10: // SCSI registers
-        LOG_F(WARNING, "AMIC: read attempt from unimplemented SCSI register");
+        return this->scsi->read((offset >> 4) & 0xF);
-        return 0;
     case 0x14: // Sound registers
         switch (offset) {
         case AMICReg::Snd_Stat_0:
@@ -133,6 +134,9 @@ void AMIC::write(uint32_t reg_start, uint32_t offset, uint32_t value, int size)
     case 0xA: // MACE registers
         this->mace->write((offset >> 4) & 0xF, value);
         return;
+    case 0x10:
+        this->scsi->write((offset >> 4) & 0xF, value);
+        return;
     case 0x14: // Sound registers
         switch(offset) {
         case AMICReg::Snd_Ctrl_0:

devices/ioctrl/amic.h

@@ -25,6 +25,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #define AMIC_H
 
 #include <devices/common/mmiodevice.h>
+#include <devices/common/scsi/ncr53c94.h>
 #include <devices/common/viacuda.h>
 #include <devices/ethernet/mace.h>
 #include <devices/serial/escc.h>
@@ -144,6 +145,7 @@ private:
     uint8_t     scsi_dma_cs = 0; // SCSI DMA control/status register value
 
     // AMIC subdevices instances
+    std::unique_ptr<Ncr53C94>       scsi;
     std::unique_ptr<EsccController> escc;
     std::unique_ptr<MaceController> mace;
     std::unique_ptr<ViaCuda>        viacuda;