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diff --git a/src/VBox/Devices/Network/DevEEPROM.h b/src/VBox/Devices/Network/DevEEPROM.h
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+/* $Id: DevEEPROM.h $ */
+/** @file
+ * DevEEPROM - Microwire-compatible 64x16-bit 93C46 EEPROM Emulation, Header.
+ */
+
+/*
+ * Copyright (C) 2007-2022 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * 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, in version 3 of the
+ * License.
+ *
+ * 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>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#ifndef VBOX_INCLUDED_SRC_Network_DevEEPROM_h
+#define VBOX_INCLUDED_SRC_Network_DevEEPROM_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <iprt/types.h>
+
+/** The current Saved state version. */
+#define EEPROM93C46_SAVEDSTATE_VERSION 1
+
+/**
+ * 93C46-compatible EEPROM device emulation.
+ *
+ * @remarks This class is intended to be used in device
+ *          emulation which imposes some restrictions if the
+ *          device supports GC execution. This is why it is a
+ *          plain-old-data structure.
+ */
+struct EEPROM93C46
+{
+    /** General definitions */
+    enum {
+        /** Size of EEPROM in words */
+        SIZE        = 64,
+        /** Number of bits per word */
+        WORD_SIZE   = 16,
+        /** Number of address bits */
+        ADDR_SIZE   = 6,
+        /** Number of bits in opcode */
+        OPCODE_SIZE = 2,
+        /** The most significant bit mask in data word */
+        DATA_MSB    = 1<<(WORD_SIZE-1),
+        /** Address mask */
+        ADDR_MASK   = (1<<ADDR_SIZE)-1,
+        /** The most significant bit mask in op+addr bit sequence */
+        OPADDR_MSB  = 1<<(OPCODE_SIZE+ADDR_SIZE-1)
+    };
+
+    enum OP {
+        OP_READ,
+        OP_WRITE,
+        OP_WRITE_ALL,
+        OP_DECODE,
+        OP_32BIT_HACK = 0x7fffffff
+    };
+
+    /**
+     * Names of signal wires
+     */
+    enum Wires {
+        WIRES_SK=0x1,    ///< Clock
+        WIRES_CS=0x2,    ///< Chip Select
+        WIRES_DI=0x4,    ///< Data In
+        WIRES_DO=0x8     ///< Data Out
+    };
+
+
+    /** @todo save and load methods */
+    void save(PCPDMDEVHLPR3 pHlp, PSSMHANDLE pSSM);
+    int  load(PCPDMDEVHLPR3 pHlp, PSSMHANDLE pSSM);
+
+    /** Actual content of EEPROM */
+    uint16_t m_au16Data[SIZE];
+
+    /** current state.
+     *
+     * EEPROM operates as a simple state machine. Events are primarily
+     * triggered at positive edge of clock signal (SK). Refer to the
+     * timing diagrams of 93C46 to get better understanding.
+     */
+    enum State {
+        /** Initial state. Waiting for start condition (CS, SK, DI high). */
+        STANDBY,
+        /** Reading data in, shifting in the bits into 'word'. */
+        READING_DI,
+        /** Writing data out, shifting out the bits from 'word'. */
+        WRITING_DO,
+        /** Waiting for CS=0 to indicate we are busy (DO=0). */
+        WAITING_CS_FALL,
+        /** Waiting for CS=1 to indicate we are ready (DO=1). */
+        WAITING_CS_RISE,
+        /** Make this enum 4-byte */
+        STATE_MAKE_32BIT_HACK = 0x7fffffff
+    } m_eState;
+    /** setting writeEnable to false prevents write and erase operations */
+    bool m_fWriteEnabled;
+    uint8_t Alignment1;
+    /** intermediate storage */
+    uint16_t m_u16Word;
+    /** currently processed bit in 'word' */
+    uint16_t m_u16Mask;
+    /** decoded address */
+    uint16_t m_u16Addr;
+    /** Data Out, Data In, Chip Select, Clock */
+    uint32_t m_u32InternalWires;
+
+    /** Current opcode decoder. When no operation has been decoded yet
+     *  it is set to OP_DECODE.
+     */
+    OP m_eOp;
+#if HC_ARCH_BITS == 64
+    uint32_t Alignment2;
+#endif
+
+#ifdef IN_RING3
+    uint32_t read();
+    void     write(uint32_t u32Wires);
+    bool     readWord(uint32_t u32Addr, uint16_t *pu16Value);
+
+    void init(const uint16_t *pu16Initial = 0);
+
+    // Operation handlers
+    State opDecode();
+    State opRead();
+    State opWrite();
+    State opWriteAll();
+
+    /** Helper method to implement write protection */
+    void storeWord(uint32_t u32Addr, uint16_t u16Value);
+#endif /* IN_RING3 */
+};
+
+#endif /* !VBOX_INCLUDED_SRC_Network_DevEEPROM_h */