Add an implementation for the Highspeed Memory Controller.

devices/hmc.cpp

@@ -0,0 +1,70 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-20 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/>.
+*/
+
+/** Highspeed Memory Controller emulation.
+
+    Author: Max Poliakovski
+*/
+
+#include "hmc.h"
+
+HMC::HMC() : MemCtrlBase()
+{
+    this->name = "Highspeed Memory Controller";
+
+    /* add memory mapped I/O region for the HMC control register */
+    add_mmio_region(0x50F40000, 0xFFFF, this);
+
+    this->config_reg = 0ULL;
+    this->bit_pos = 0;
+}
+
+bool HMC::supports_type(HWCompType type) {
+    if (type == HWCompType::MEM_CTRL || type == HWCompType::MMIO_DEV) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+uint32_t HMC::read(uint32_t reg_start, uint32_t offset, int size)
+{
+    if (!offset)
+        return !!(this->config_reg & (1ULL << this->bit_pos++));
+    else
+        return 0; /* FIXME: what should be returned for invalid offsets? */
+}
+
+void HMC::write(uint32_t reg_start, uint32_t offset, uint32_t value, int size)
+{
+    uint64_t bit;
+
+    switch(offset) {
+        case 0:
+            bit = 1ULL << this->bit_pos++;
+            this->config_reg = (value & 1) ? this->config_reg | bit :
+                               this->config_reg & ~bit;
+            break;
+        case 8: /* writing to HMCBase + 8 resets internal bit position */
+            this->bit_pos = 0;
+            break;
+    }
+}

devices/hmc.h

@@ -0,0 +1,54 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-20 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/>.
+*/
+
+/** Highspeed Memory Controller emulation.
+
+    Author: Max Poliakovski
+
+    Highspeed Memory Controller (HMC) is a custom memory
+    and L2 cache controller designed especially for the
+    first generation of the PowerMacintosh computer.
+*/
+
+#ifndef HMC_H
+#define HMC_H
+
+#include "hwcomponent.h"
+#include "memctrlbase.h"
+#include "mmiodevice.h"
+
+class HMC : public MemCtrlBase, public MMIODevice {
+public:
+    HMC();
+    ~HMC() = default;
+
+    bool supports_type(HWCompType type);
+
+    /* MMIODevice methods */
+    uint32_t read(uint32_t reg_start, uint32_t offset, int size);
+    void write(uint32_t reg_start, uint32_t offset, uint32_t value, int size);
+
+private:
+    int      bit_pos;
+    uint64_t config_reg;
+};
+
+#endif // HMC_H