Generic I2C PROM emulation.

devices/common/i2c/i2cprom.cpp

@@ -0,0 +1,76 @@
+/*
+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/>.
+*/
+
+/** @file Generic PROM device programmable over I2C. */
+
+#include <devices/common/i2c/i2cprom.h>
+#include <loguru.hpp>
+
+#include <cinttypes>
+#include <cstring>
+#include <memory>
+
+I2CProm::I2CProm(uint8_t dev_addr, int size)
+{
+    supports_types(HWCompType::I2C_DEV);
+
+    this->my_addr  = dev_addr;
+    this->rom_size = size;
+
+    // allocate storage for ROM data
+    this->data = std::unique_ptr<uint8_t[]> (new uint8_t[this->rom_size]);
+}
+
+void I2CProm::fill_memory(int start, int size, uint8_t c)
+{
+    if ((start + size) <= this->rom_size) {
+        std::memset(&this->data[start], c, size);
+    }
+}
+
+void I2CProm::set_memory(int start, const uint8_t* in_data, int size)
+{
+    if ((start + size) <= this->rom_size) {
+        std::memcpy(&this->data[start], in_data, size);
+    }
+}
+
+void I2CProm::start_transaction() {
+    this->pos = 0;
+};
+
+bool I2CProm::send_subaddress(uint8_t sub_addr) {
+    this->pos = sub_addr;
+    return true;
+};
+
+bool I2CProm::send_byte(uint8_t data) {
+    LOG_F(9, "I2CRom: 0x%X received", data);
+    return true;
+};
+
+bool I2CProm::receive_byte(uint8_t* p_data) {
+    if (this->pos >= this->rom_size) {
+        this->pos = 0; // attempt to read past last byte should wrap around
+    }
+    *p_data = this->data[this->pos++];
+    return true;
+};

devices/common/i2c/i2cprom.h

@@ -0,0 +1,57 @@
+/*
+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/>.
+*/
+
+/** @file Generic PROM device programmable over I2C. */
+
+#ifndef I2C_PROM_H
+#define I2C_PROM_H
+
+#include <devices/common/hwcomponent.h>
+#include <devices/common/i2c/i2c.h>
+
+#include <cinttypes>
+#include <memory>
+
+class I2CProm : public I2CDevice, public HWComponent
+{
+public:
+    I2CProm(uint8_t dev_addr, int size);
+    ~I2CProm() = default;
+
+    // I2CDevice methods
+    void start_transaction();
+    bool send_subaddress(uint8_t sub_addr);
+    bool send_byte(uint8_t data);
+    bool receive_byte(uint8_t* p_data);
+
+    // data management methods
+    void fill_memory(int start, int size, uint8_t c);
+    void set_memory(int start, const uint8_t* in_data, int size);
+
+private:
+    std::unique_ptr<uint8_t[]>  data;
+
+    int     rom_size    = 0;
+    int     pos         = 0;
+    uint8_t my_addr     = 0xA0;
+};
+
+#endif // I2C_PROM_H