Build Linux Kernel

WARNING

This chapter is work in progress.

In the previous chapter, we successfully booted our tiny Hello World program. However, it was not fun enough. Our next target is the real-world operating system, Linux!

Before supporting Linux in our hypervisor, we need the boot image of Linux. Let's build it.

Download Linux kernel config

TODO:

Build with Docker

linux/Dockerfile

FROM ubuntu:24.04

RUN apt-get update && apt-get install -y \
    curl \
    tar \
    build-essential \
    gcc-riscv64-linux-gnu \
    binutils-riscv64-linux-gnu \
    libncurses-dev \
    flex \
    bison \
    bc

RUN curl -fSLO https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.12.34.tar.xz
RUN tar xf linux-6.12.34.tar.xz && \
    mv linux-6.12.34 kernel

WORKDIR /kernel

ENV CROSS_COMPILE=riscv64-linux-gnu-
ENV ARCH=riscv

COPY linux.config .config

linux/build.sh

#!/bin/bash
cd "$(dirname "$0")"

docker build -t guest-linux-builder -f Dockerfile .

# Build Linux kernel, and copy the Image to this directory.
docker run -v $PWD:/linux -it guest-linux-builder \
    bash -c 'make -j$(nproc) Image && cp arch/riscv/boot/Image /linux/Image && cp vmlinux /linux/vmlinux'

$ ./linux/build.sh

$ ls -alh linux 
total 99M
drwxr-xr-x  7 seiya staff  224 Jul 24 15:37 .
drwxr-xr-x 24 seiya staff  768 Jul 24 15:37 ..
-rwxr-xr-x  1 seiya staff  304 Jul 24 15:37 build.sh
-rw-r--r--  1 seiya staff  461 Jul 24 15:37 Dockerfile
-rwxr-xr-x  1 seiya staff 5.2M Jul 23 20:12 Image
-rw-r--r--  1 seiya staff  43K Jul 24 15:37 linux.config
-rwxr-xr-x  1 seiya staff  93M Jul 23 20:12 vmlinux