#!/usr/bin/bash
#
# SPDX-FileCopyrightText: 2022 Celeste Liu <CoelacanthusHex@gmail.com>
# SPDX-License-Identifier: GPL-3.0-or-later

# shellcheck disable=1091
. /usr/share/makepkg/util.sh
colorize

verbose=0
use_fixed_password=0
varbose_arg=
rootfs="archriscv-$(date --rfc-3339=date).tar.zst"

show_help() {
cat << EOF
Usage: ${0##*/} [-hvf] [-p PASSWORD] [-r ROOTFS] [FILENAME]
Create Arch RISC-V qemu image.

    FILENAME    generated image file name
                default: 'archriscv-$(date --rfc-3339=date).qcow2'

    -h          display this help and exit
    -f          use fixed password instead of using systemd-firstboot to ask
    -p PASSWORD set root password to PASSWORD instead of passwd in rootfs
    -r ROOTFS   specify rootfs file name
    -v          verbose mode
EOF
}

parse-args() {
    local OPTIND=1
    while getopts 'hvfr:p:' opt; do
      case $opt in
        h)
            show_help
            exit 0
            ;;
        v)  verbose=$((verbose+1))
            varbose_arg="--verbose"
            ;;
        f)
            use_fixed_password=1
            ;;
        p)  password=$OPTARG
            ;;
        r)  rootfs=$OPTARG
            ;;
        *)
            show_help >&2
            exit 1
            ;;
      esac
  done
  shift "$(( OPTIND-1 ))"
  filename=${1:-archriscv-$(date --rfc-3339=date).qcow2}
}

toggle-systemd-firstboot() {
    msg2 "Toggle systemd-firstboot..."
    sudo rm -f qcow2/etc/{machine-id,hostname,shadow}
    sudo systemd-nspawn -D qcow2 systemctl enable systemd-firstboot.service
}

use-fixed-password() {
    msg2 "Using fixed password... $password"
    [[ -n $password ]] && sudo usermod --root $(realpath ./qcow2) --password $(openssl passwd -6 "$password") root
}

parse-args "$@"

msg "Building u-boot..."

[[ -d u-boot ]] || git clone https://github.com/u-boot/u-boot.git
pushd u-boot
git checkout master -- ':(top)'
git checkout master
git pull --rebase
git checkout v2023.04

make \
    CROSS_COMPILE=riscv64-linux-gnu- \
    qemu-riscv64_smode_defconfig
make CROSS_COMPILE=riscv64-linux-gnu-
popd

msg "Building OpenSBI..."

[[ -d opensbi ]] || git clone https://github.com/riscv-software-src/opensbi
pushd opensbi
git checkout master -- ':(top)'
git checkout master
git pull --rebase
git checkout v1.1

make \
    CROSS_COMPILE=riscv64-linux-gnu- \
    PLATFORM=generic \
    FW_PAYLOAD_PATH=../u-boot/u-boot.bin
popd

cp ./opensbi/build/platform/generic/firmware/fw_payload.bin opensbi_fw_payload.bin

msg "Create image file..."
qemu-img create -f qcow2 "$filename" 10G
sudo modprobe nbd max_part=16 || exit 1
sudo qemu-nbd -c /dev/nbd0 "$filename"

sudo sfdisk /dev/nbd0 <<EOF
label: dos
label-id: 0x17527589
device: /dev/nbd0
unit: sectors

/dev/nbd0p1 : start=        2048, type=83, bootable
EOF

sudo mkfs.ext4 /dev/nbd0p1
sudo e2label /dev/nbd0p1 rootfs

sudo mkdir -p qcow2
sudo mount /dev/nbd0p1 qcow2
sudo chown root:root qcow2

msg "Extract rootfs..."

pushd qcow2
sudo bsdtar $varbose_arg -pxf "../$rootfs"
popd

msg "Install kernel package..."

sudo systemd-nspawn -D qcow2 pacman \
    --noconfirm \
    -Syu linux linux-firmware

sudo mkdir -p qcow2/boot/extlinux
cat << EOF | sudo tee qcow2/boot/extlinux/extlinux.conf
menu title Arch RISC-V QEMU Boot
timeout 100
default linux

label linux
    menu label Linux linux
    kernel /boot/vmlinuz-linux
    initrd /boot/initramfs-linux-fallback.img
    append earlyprintk rw root=/dev/vda1 rootwait rootfstype=ext4 LANG=en_US.UTF-8 console=ttyS0
EOF

cat << EOF | sudo tee qcow2/etc/systemd/network/default.network
[Match]
Name=en*

[Network]
DHCP=yes
EOF
sudo systemd-nspawn -D qcow2 systemctl enable systemd-networkd.service

msg "Clean up..."
msg2 "Clean up pacman package cache..."
yes y | sudo pacman \
    --sysroot ./qcow2 \
    --sync --clean --clean

(( use_fixed_password==0 )) && toggle-systemd-firstboot || use-fixed-password

msg2 "Unmount..."
sudo umount qcow2
sudo qemu-nbd -d /dev/nbd0