dynarmic-android/include/dynarmic/callbacks.h

/* This file is part of the dynarmic project.
 * Copyright (c) 2016 MerryMage
 * This software may be used and distributed according to the terms of the GNU
 * General Public License version 2 or any later version.
 */

#pragma once

#include <array>
#include <cstddef>
#include <cstdint>
#include <memory>

namespace Dynarmic {

class Coprocessor;
class Jit;

/// These function pointers may be inserted into compiled code.
struct UserCallbacks {
    // All reads through this callback are 4-byte aligned.
    // Memory must be interpreted as little endian.
    std::uint32_t (*MemoryReadCode)(std::uint32_t vaddr);

    // Reads through these callbacks may not be aligned.
    // Memory must be interpreted as if ENDIANSTATE == 0, endianness will be corrected by the JIT.
    std::uint8_t (*MemoryRead8)(std::uint32_t vaddr);
    std::uint16_t (*MemoryRead16)(std::uint32_t vaddr);
    std::uint32_t (*MemoryRead32)(std::uint32_t vaddr);
    std::uint64_t (*MemoryRead64)(std::uint32_t vaddr);

    // Writes through these callbacks may not be aligned.
    // Memory must be interpreted as if ENDIANSTATE == 0, endianness will be corrected by the JIT.
    void (*MemoryWrite8)(std::uint32_t vaddr, std::uint8_t value);
    void (*MemoryWrite16)(std::uint32_t vaddr, std::uint16_t value);
    void (*MemoryWrite32)(std::uint32_t vaddr, std::uint32_t value);
    void (*MemoryWrite64)(std::uint32_t vaddr, std::uint64_t value);

    // If this callback returns true, the JIT will assume MemoryRead* callbacks will always
    // return the same value at any point in time for this vaddr. The JIT may use this information
    // in optimizations.
    // An conservative implementation that always returns false is safe.
    bool (*IsReadOnlyMemory)(std::uint32_t vaddr);

    /// The intrepreter must execute only one instruction at PC.
    void (*InterpreterFallback)(std::uint32_t pc, Jit* jit, void* user_arg);
    void* user_arg = nullptr;

    // This callback is called whenever a SVC instruction is executed.
    void (*CallSVC)(std::uint32_t swi);

    // Page Table
    // The page table is used for faster memory access. If an entry in the table is nullptr,
    // the JIT will fallback to calling the MemoryRead*/MemoryWrite* callbacks.
    static constexpr std::size_t PAGE_BITS = 12;
    static constexpr std::size_t NUM_PAGE_TABLE_ENTRIES = 1 << (32 - PAGE_BITS);
    std::array<std::uint8_t*, NUM_PAGE_TABLE_ENTRIES>* page_table = nullptr;

    // Coprocessors
    std::array<std::shared_ptr<Coprocessor>, 16> coprocessors;
};

} // namespace Dynarmic