Build Linux Kernel (v5.10) for use in a Firecracker VM

build-5.10-firecracker-kernel-image.sh

#!/usr/bin/env bash
# Note that this doesn't work on Ubuntu 22.04, but works on 20.04. This seem to be due to the newer kernel used by default on newer Ubuntu versions (YMMV)

set -euo pipefail

# Install system deps
apt-get update && apt-get upgrade -y && sudo apt-get install \
    bison \
    build-essential \
    flex \
    git \
    libelf-dev \
    libncurses5-dev \
    libssl-dev -y

# Shallow clone of specific branch we're targeting
git clone --branch v5.10 --depth=1 https://github.com/torvalds/linux.git

# Download hosted config for v5.10
curl -fsSL -o 5-10-config https://raw.githubusercontent.com/firecracker-microvm/firecracker/main/resources/guest_configs/microvm-kernel-x86_64-5.10.config
cp 5-10-config linux/.config
(cd linux && make olddefconfig) # Accept defaults for any new options
(cd linux && make vmlinux -j32) # Build using 32 threads