Semiautomated qemu kernel development

qemu_kernel_dev.sh

#!/bin/bash

#
# Create qemu image to test kernel builds
#

# defines
MNT_PATH=~/qemu/
MNT=rootfs
QEMU_PATH=~/qemu
QEMU_IMG=qemu.img
KERNEL_PATH=~/code/linux
KERNEL_BUILD_DIR=$KERNEL_PATH/build/arch/x86_64/boot
KERNEL_IMG=bzImage
UBUNTU_VERSION=zesty

function create_qemu_base_image {
	# create qemu image
	qemu-img create $QEMU_PATH/$QEMU_IMG 8G
	mkfs.ext4 $QEMU_PATH/$QEMU_IMG

	# mount qemu image
	mkdir -p $MNT_PATH/$MNT
	sudo mount -oloop $QEMU_PATH/$QEMU_IMG $MNT_PATH/$MNT

	# install basic ubuntu image
	sudo debootstrap --arch=amd64 --variant=buildd $UBUNTU_VERSION rootfs http://archive.ubuntu.com/ubuntu/
	sudo cp /etc/resolv.conf "$MNT_PATH/$MNT/etc/resolv.conf"
	cat <<REPO_LIST | sudo tee "$MNT_PATH/$MNT/etc/apt/sources.list"
# Repositories
deb http://archive.ubuntu.com/ubuntu $UBUNTU_VERSION main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu $UBUNTU_VERSION-security main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu $UBUNTU_VERSION-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu $UBUNTU_VERSION-backports main restricted universe multiverse
REPO_LIST

	# chroot
	sudo mount --bind /dev $MNT_PATH/$MNT/dev
	sudo mount --bind /proc $MNT_PATH/$MNT/proc
	sudo mount --bind /sys $MNT_PATH/$MNT/sys
	sudo chroot "$MNT_PATH/$MNT" /usr/bin/env PATH=/usr/sbin:/usr/bin/:/bin:/sbin bash -i

	# add root password
	passwd

	# install sw, create users or whatever
	apt-get update
	apt-get install ubuntu-gnome-desktop -y
	apt-get install qv4l2 gstreamer1.0 git build-essential locales sudo -y

	# unmount everything
	exit
	sudo umount $MNT_PATH/$MNT/dev
	sudo umount $MNT_PATH/$MNT/proc
	sudo umount $MNT_PATH/$MNT/sys
	sudo umount $MNT_PATH/$MNT
}

function mount_and_chroot_qemu_img {
	# mount qemu image
	mkdir -p $MNT_PATH/$MNT
	sudo mount -oloop $QEMU_PATH/$QEMU_IMG $MNT_PATH/$MNT
	# chroot
	sudo mount --bind /dev $MNT_PATH/$MNT/dev
	sudo mount --bind /proc $MNT_PATH/$MNT/proc
	sudo mount --bind /sys $MNT_PATH/$MNT/sys
	sudo chroot "$MNT_PATH/$MNT" /usr/bin/env PATH=/usr/sbin:/usr/bin/:/bin:/sbin bash -i
	# at this point you can safely install whatever packages needed to exit just write exit
}

function clean_chroot {
	# unmount everything
	sudo umount $MNT_PATH/$MNT/dev
	sudo umount $MNT_PATH/$MNT/proc
	sudo umount $MNT_PATH/$MNT/sys
	sudo umount $MNT_PATH/$MNT

	# remove mount dir
	rm -r $MNT_PATH/$MNT
}

function launch_qemu {
	sudo qemu-system-x86_64 -hda $QEMU_PATH/$QEMU_IMG -m 4G -smp 4 --enable-kvm --kernel $KERNEL_BUILD_DIR/$KERNEL_IMG --append "root=/dev/sda rw"
}

function linux_configure {
	mkdir -p build
	make O=build x86_64_defconfig
	make O=build kvmconfig
}

function linux_build_and_install {

	# move to linux dir
	cd $KERNEL_PATH

	# mount qemu image
	mkdir -p $MNT_PATH/$MNT
	sudo mount -oloop $QEMU_PATH/$QEMU_IMG $MNT_PATH/$MNT

	# build and install
	mkdir -p build
	make O=build -j8
	sudo make O=build modules_install INSTALL_MOD_PATH=$MNT_PATH/$MNT
	sudo make O=build headers_install INSTALL_HDR_PATH=$MNT_PATH/$MNT
	sudo make O=build install INSTALL_HDR_PATH=$MNT_PATH/$MNT

	# move back to previous dir
	cd -

	# build fbsrc driver and copy it into the image
	cd ~/code/fbsrc
	make KDIR=$KERNEL_PATH/build/
	cp fbsrc.ko $MNT_PATH/$MNT/home/nico
	cd -

	#cleanup
	sudo umount $MNT_PATH/$MNT

}


linux_build_and_install
launch_qemu