Basic Gazelle (PM 6500) emulation.

2025-01-10 13:29:38 +00:00 · 2022-12-23 17:12:09 +01:00 · 2022-12-23 17:12:09 +01:00 · 41a34ffab6
commit 41a34ffab6
parent 8002737124
1 changed files with 109 additions and 0 deletions
--- a/machines/machinegazelle.cpp
+++ b/machines/machinegazelle.cpp
@ -0,0 +1,109 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-22 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/>.
+*/
+
+/** Constructs a Gazelle style machine. This family includes
+    Power Macintosh 5500, 6500 and Twentieth Anniversary Mac.
+ */
+
+#include <cpu/ppc/ppcemu.h>
+#include <devices/memctrl/psx.h>
+#include <devices/common/pci/pcihost.h>
+#include <devices/ioctrl/macio.h>
+#include <machines/machinebase.h>
+#include <machines/machinefactory.h>
+#include <machines/machineproperties.h>
+
+// TODO: move it to /cpu/ppc
+int get_cpu_pll_value(const uint64_t cpu_freq_hz) {
+    switch (cpu_freq_hz / 1000000) {
+    case 225:
+        return 7;  // 4.5:1 ratio
+    case 250:
+        return 11; // 5:1 ratio
+    case 275:
+        return 9;  // 5.5:1 ratio
+    default:
+        ABORT_F("Unsupported CPU frequency %llu Hz", cpu_freq_hz);
+    }
+}
+
+int initialize_gazelle(std::string& id)
+{
+    PCIHost *pci_host = dynamic_cast<PCIHost*>(gMachineObj->get_comp_by_name("PsxPci1"));
+
+    // register O'Hare I/O controller with the main PCI bus
+    pci_host->pci_register_device(
+        32, dynamic_cast<PCIDevice*>(gMachineObj->get_comp_by_name("OHare")));
+
+    PsxCtrl* psx_obj = dynamic_cast<PsxCtrl*>(gMachineObj->get_comp_by_name("Psx"));
+
+    // allocate ROM region
+    if (!psx_obj->add_rom_region(0xFFC00000, 0x400000)) {
+        LOG_F(ERROR, "Could not allocate ROM region!");
+        return -1;
+    }
+
+    // plug 8MB RAM DIMM into slot #0
+    psx_obj->insert_ram_dimm(0, DRAM_CAP_32MB);
+
+    // allocate and map physical RAM
+    psx_obj->map_phys_ram();
+
+    // configure CPU clocks
+    uint64_t bus_freq      = 50000000ULL;
+    uint64_t timebase_freq = bus_freq / 4;
+
+    // init virtual CPU and request MPC603ev
+    ppc_cpu_init(psx_obj, PPC_VER::MPC603EV, timebase_freq);
+
+    ppc_state.spr[SPR::HID1] = get_cpu_pll_value(225000000) << 28;
+
+    return 0;
+}
+
+static const PropMap pm6500_settings = {
+    {"rambank1_size",
+        new IntProperty(16, vector<uint32_t>({4, 8, 16, 32, 64, 128}))},
+    {"rambank2_size",
+        new IntProperty( 0, vector<uint32_t>({0, 4, 8, 16, 32, 64, 128}))},
+    {"rambank3_size",
+        new IntProperty( 0, vector<uint32_t>({0, 4, 8, 16, 32, 64, 128}))},
+    {"rambank4_size",
+        new IntProperty( 0, vector<uint32_t>({0, 4, 8, 16, 32, 64, 128}))},
+    {"gfxmem_size",
+        new IntProperty( 1, vector<uint32_t>({1, 2, 4}))},
+    {"emmo",
+        new BinProperty(0)},
+};
+
+static vector<string> pm6500_devices = {
+    "Psx", "PsxPci1", "OHare"
+};
+
+static const MachineDescription pm6500_descriptor = {
+    .name = "pm6500",
+    .description = "Power Macintosh 6500",
+    .devices = pm6500_devices,
+    .settings = pm6500_settings,
+    .init_func = &initialize_gazelle
+};
+
+REGISTER_MACHINE(pm6500, pm6500_descriptor);