从控制台访问 em-dosbox 内存

Question

there's DosBox（一个 Dos 模拟器）的这个 emscripten 端口允许运行浏览器中的旧 DOS 软件。现在我想要实现的是创建某种内存扫描器，允许在 dosbox 中调整一些内存值。我查看了 Google Chrome 配置文件选项卡，它显示 DosBox 创建了一个看起来像整个程序内存的大型 UInt 数组，但我不知道如何访问它。

有什么想法吗？提前致谢！

Answer 1

Emscripten 的默认设置在页面的全局范围内放置一个 Module 对象，其中包含用作程序内存的数组缓冲区的各种视图。例如，

Module.HEAPU8

是 Uint8Array 视图。查看使用 Emscripten 的 https://archive.org/details/msdos_Prince_of_Persia_1990 的控制台，完整列表为：

Module.HEAP16
Module.HEAP32
Module.HEAPF32
Module.HEAPF64
Module.HEAPU8
Module.HEAPU16
Module.HEAPU32

Answer 2

仅供参考，这是我用过的扫描码

class MemoryScanner {
  constructor(target) {
    this.set = new Set();
    this.target = target;
  }

  search(value) {
    let target = this.target, length = target.length, set = this.set;
    for (let i = 0; i < length; i++) {
      if (target[i] === value) {
        set.add(i);
      }
    }
  }

  search2(value1, value2) {
    let target = this.target, length = target.length, set = this.set;
    for (let i = 0; i < length; i++) {
      if (target[i] === value1 && target[i + 1] === value2) {
        set.add(i);
      }
    }
  }

  search4(value1, value2, value3, value4) {
    let target = this.target, length = target.length, set = this.set;
    for (let i = 0; i < length; i++) {
      if (target[i + 0] === value1 &&
          target[i + 1] === value2 &&
          target[i + 2] === value3 &&
          target[i + 3] === value4) {
        set.add(i);
      }
    }
  }

  search8(value1, value2, value3, value4, value5, value6, value7, value8) {
    let target = this.target, length = target.length, set = this.set;
    for (let i = 0; i < length; i++) {
      if (target[i + 0] === value1 &&
          target[i + 1] === value2 &&
          target[i + 2] === value3 &&
          target[i + 3] === value4 &&
          target[i + 4] === value5 &&
          target[i + 5] === value6 &&
          target[i + 6] === value7 &&
          target[i + 7] === value8) {
        set.add(i);
      }
    }
  }

  intersect(value) {
    let target = this.target, length = target.length, set = this.set;

    for (let index of this.set) {
      if (target[index] !== value) {
        set.delete(index)
      }
    }
  }

  intersect2(value1, value2) {
    let target = this.target, length = target.length, set = this.set;

    for (let index of this.set) {
      if (target[index] !== value1 || target[index + 1] !== value2) {
        set.delete(index)
      }
    }
  }

  intersect4(value1, value2, value3, value4) {
    let target = this.target, length = target.length, set = this.set;

    for (let index of this.set) {
      if (target[index + 0] !== value1 ||
          target[index + 1] !== value2 ||
          target[index + 2] !== value3 ||
          target[index + 3] !== value4) {
        set.delete(index)
      }
    }
  }

  intersect8(value1, value2, value3, value4, value5, value6, value7, value8) {
    let target = this.target, length = target.length, set = this.set;

    for (let index of this.set) {
      if (target[index + 0] !== value1 ||
          target[index + 1] !== value2 ||
          target[index + 2] !== value3 ||
          target[index + 3] !== value4 ||
          target[index + 4] !== value5 ||
          target[index + 5] !== value6 ||
          target[index + 6] !== value7 ||
          target[index + 7] !== value8) {
        set.delete(index)
      }
    }
  }
}

从控制台访问 em-dosbox 内存

Access em-dosbox memory from console

dosbox

emscripten