#!/bin/bash

# build/tmp-glibc/work/x86_64-linux/qemu-helper-native/1.0-r1/recipe-sysroot-native/usr/bin/qemu-system-x86_64

SCRIPT=$(realpath ${BASH_SOURCE})
BUILD_ROOT=$(realpath $(dirname ${SCRIPT})/../build)
SYSROOT=${BUILD_ROOT}/tmp-glibc/work/x86_64-linux/qemu-helper-native/1.0-r1/recipe-sysroot-native
QEMU=${SYSROOT}/usr/bin/qemu-system-x86_64


if [[ ! -f ${QEMU} ]]; then
    >&2 printf "Qemu binary not found at: ${QEMU}\n"
    exit 1
fi

ENABLE_KVM="--enable-kvm -cpu host"

if [[ ! -c "/dev/kvm" ]]; then
    printf "Disabling KVM because /dev/kvm is not available\n"
    ENABLE_KVM=""
fi

EFI_BIOS="-bios /usr/share/qemu/OVMF.fd" 
if [[ ! -f "/usr/share/qemu/OVMF.fd" ]]; then
    printf "Disabling EFI boot because OVMF.fd not found in /usr/share/qemu\n"
    EFI_BIOS=""
fi

usage() {
cat <<-EOF
USAGE: qemu-boot [options] installer      Boot build/images/citadel-installer.img
       qemu-boot [options] kernel         Boot build/images/bzImage

OPTIONS

    --no-efi               Do not use OVMF UEFI bios
    --memory size          Set custom guest RAM size

To exit kernel boot type 'ctrl-a x' (See escape sequences in qemu-system man page)

EOF
exit 0
}

BOOT_TARGET=""
MEMORY_ARG="-m 4G"

while [[ $# -gt 0 ]]; do
    key=${1}
    case $key in
        --no-efi)
            EFI_BIOS=""
            shift
            ;;
        --memory)
            MEMORY_ARG="-m ${2}"
            shift
            shift
            ;;
        kernel)
            BOOT_TARGET="kernel"
            shift
            ;;
        installer)
            BOOT_TARGET="installer"
            shift
            ;;
        --help)
            usage
            ;;
        *)
            printf "Unknown option ${key}\n"
            usage
            ;;
    esac
done

boot_installer() {
    ${QEMU} \
        ${ENABLE_KVM} \
        ${EFI_BIOS} \
        ${MEMORY_ARG} \
      -vga virtio \
      -usb -device usb-tablet,id=input0 \
      -drive format=raw,file=${BUILD_ROOT}/images/citadel-installer.img \
      -net none \
      -smp 2
}

boot_kernel() {
    echo "kernel"
    ${QEMU} \
        ${ENABLE_KVM} \
        ${MEMORY_ARG} \
        -nographic \
        -smp 2 \
        -append "rd.emergency console=ttyS0 earlyprintk=ttyS0" \
        -kernel ${BUILD_ROOT}/images/bzImage
}

if [[ ${BOOT_TARGET} = "kernel" ]]; then
    boot_kernel
elif [[ ${BOOT_TARGET} = "installer" ]]; then
    boot_installer
else
    usage
fi