← 返回日报
略读 预计 1 分钟

Kernel that only runs an NES emulator

摘要

这是一个极简内核项目，只包含运行 NES 模拟器所需的最小功能，无需操作系统即可启动，没有分页、用户态或任何保护机制，只能运行一个程序，且程序代码与内核一同编译。项目提供 make 构建方式，需 i686 交叉编译器，并附有 mandelbrot、paleta、corazon 三个示例程序。安装可通过 GRUB2 引导 kernel.elf，测试用 QEMU 运行磁盘镜像，可选依赖包括 GRUB2、QEMU、Doxygen 等。文档还说明了启动调用栈、文件夹结构，并包含一份西班牙语的大学报告。

荐读理由

这个极简内核把 NES 模拟器直接编译进内核、无分页无用户态，可作为你研究裸机启动与最小内核设计的现成参考，动手改改就能跑

原文

Introduction

Nintendo Entertainment Kernel is a very basic kernel with only the minimun to run a NES emulator. This means that it can be run without any OS. It does not have pagging nor userspace nor any kind of protection at all. Only one program can be run. It is embedded in the kernel, which means the program's code is compiled alongside the kernel.

Screenshots

alt Home Screen

alt Mario Bros

Building

You should use make and provide the cross compiler:

PATH=/path/to/crosscompiler/bin:$PATH make kernel program=emulador

If there are not errors, kernel.elf should be in the bin folder.

Examples

Besides "emulador" there are three other working programs:

  • mandelbrot (shows a explorable fractal)

  • paleta (shows nes avalaible colors)

  • corazon (a heart animation using math functions)

All of them can be compiled with the kernel using make.

Ej: make program=examples/mandelbrot

Installing

You may copy kernel.elf to /boot/ and add an entry at /etc/grub.d/40_custom like:

menuentry "nek" {

multiboot /boot/kernel.elf module /boot/initrd.img

}

Remember to update the config file:

sudo grub-mkconfig -o /boot/grub/grub.cfg

Testing

The makefile should run QEMU using the disk image disk.img. A loop device to this file must have been set up in the mount folder.

Dependencies

  • i686 cross compiler (both C and ASM), like GCC and nasm

  • GRUB2(optional): Generates .iso (cd image)

  • QEMU(optional): Emulation

  • Doxygen and Graphviz (optional): For generating the documentation

  • grub-mkrescue (optional): For generating a booteable cd image (.iso)

Boot call stack

GRUB (multiboot standard)

kernel/arch/x86/init/boot.s <-- calls c code, initializes stack

kernel_entry() at kernel/arch/x86/init/kernel_entry.c <--base system initilization

kmain() at kernel/kmain.c <--- some services are started

main() at program/main.(c|cpp) <--- main program

Folder Structure

  • kernel folder has all related to the kernel

  • kernel/arch code that depends on the architecture

  • kernel/fs file system(currently only vfs implemented)

  • fdlibm: a math library downloaded from internet

  • util/specs: Some useful documents

  • informe: University report (in spanish)

  • iso: a few files to generate an .iso with the kernel

  • util: contains the program to generate the initrd and a few other things

  • util/fuente: Tools/file used to generate the console font

Lobsters · 1 赞 · 0 评 讨论 → 阅读原文 →

这条对你有帮助吗？