xv6内核构建

概念

  • xv6

Xv6是由麻省理工学院(MIT)为操作系统工程的课程（代号6.828）,开发的一个教学目的的操作系统。

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准备

设备：Win11

环境：WSL2

WSL 版本： 2.0.14.0
内核版本： 5.15.133.1-1
WSLg 版本： 1.0.59
MSRDC 版本： 1.2.4677
Direct3D 版本： 1.611.1-81528511
DXCore 版本： 10.0.25131.1002-220531-1700.rs-onecore-base2-hyp
Windows 版本： 10.0.22631.2861

Linux：Debian

Linux foolish-pc 5.15.133.1-microsoft-standard-WSL2 #1 SMP Thu Oct 5 21:02:42 UTC 2023 x86_64 GNU/Linux

源码：XV6

环境配置

Note: WSL环境配置略

源代码下载

本文主要是对RISC-V架构的xv6)项目进行构建

Risc-V工具链下载

源代码下载

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git clone https://github.com/riscv/riscv-gnu-toolchain

下载必要的工具

On Ubuntu, executing the following command should suffice:

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$ sudo apt-get install autoconf automake autotools-dev curl python3 python3-pip libmpc-dev libmpfr-dev libgmp-dev gawk build-essential bison flex texinfo gperf libtool patchutils bc zlib1g-dev libexpat-dev ninja-build git cmake libglib2.0-dev

On Fedora/CentOS/RHEL OS, executing the following command should suffice:

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$ sudo yum install autoconf automake python3 libmpc-devel mpfr-devel gmp-devel gawk  bison flex texinfo patchutils gcc gcc-c++ zlib-devel expat-devel

On Arch Linux, executing the following command should suffice:

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$ sudo pacman -Syyu autoconf automake curl python3 libmpc mpfr gmp gawk base-devel bison flex texinfo gperf libtool patchutils bc zlib expat

Also available for Arch users on the AUR: https://aur.archlinux.org/packages/riscv-gnu-toolchain-bin

On OS X, you can use Homebrew to install the dependencies:

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$ brew install python3 gawk gnu-sed gmp mpfr libmpc isl zlib expat texinfo flock

构建

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./configure --prefix=/opt/riscv
make

构建完成后会在/opt/riscv下生成工具链

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➜  riscv-gnu-toolchain git:(master) ll /opt/riscv
total 24K
drwxr-xr-x 2 root root 4.0K Jan  4 08:22 bin
drwxr-xr-x 4 root root 4.0K Jan  4 08:22 include
drwxr-xr-x 4 root root 4.0K Jan  4 08:22 lib
drwxr-xr-x 3 root root 4.0K Jan  3 23:21 libexec
drwxr-xr-x 5 root root 4.0K Jan  3 23:24 riscv64-unknown-elf
drwxr-xr-x 7 root root 4.0K Jan  4 08:22 share

安装qemu

官方教程

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sudo apt install qemu-system

构建

修改xv6 Makefile

/opt/riscv/bin/

Note：

记住路径末尾一定得加/而且不能有空格（因为xv6是直接将TOOLPREFIX和工具拼接）

否则就会报错Permission Denied

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# riscv64-unknown-elf- or riscv64-linux-gnu-
# perhaps in /opt/riscv/bin
TOOLPREFIX = /opt/riscv/bin/

除此之外由于risc-v工具链编译的文件为了防止重名加了一个riscv64-unknown-elf-的前缀。

我们还需要软连接一下

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for file in /opt/riscv/bin/riscv64-unknown-elf-*; do
    ln -s "$file" "$(basename "$file" | sed 's/^riscv64-unknown-elf-//')"
done
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make qemu

坑点

  1. 千万，千万，千万！！！不能将RiscV工具链设置到Path中

很可能会覆盖掉原本的gcc，导致程序运行的各种错误

参考

XV6 Doc