#!/usr/bin/env bash

check_sudo() {
    if [ "$EUID" -ne 0 ]; then
        echo "This script must be executed as root. Please run with sudo."
        exit 1
    fi
}

detach_gpu() {
    echo "Detaching GPU from host..."

    # Stop display manager
    systemctl stop display-manager

    # Unbind VTconsoles
    for F in /sys/class/vtconsole/vtcon*; do
        echo 0 > "$F/bind"
    done

    # Unbind EFI Framebuffer
    for F in /sys/bus/platform/drivers/efi-framebuffer/efi-framebuffer.*; do
        test ! -d "$F" && continue
        echo "$(basename "$F")" > /sys/bus/platform/drivers/efi-framebuffer/unbind
    done

    # Unload AMD kernel module
    lsof | grep amdgpu | awk '{print $2}' | xargs sudo kill -9
    fuser -k /dev/dri/card1
    modprobe -r amdgpu

    echo "Unbinding GPU from current driver..."
    echo "0000:0d:00.0" > /sys/bus/pci/devices/0000:0d:00.0/driver/unbind

    echo "Unbinding GPU audio from current driver..."
    echo "0000:0d:00.1" > /sys/bus/pci/devices/0000:0d:00.1/driver/unbind

    echo "Binding GPU to vfio-pci driver..."
    modprobe vendor-reset
    modprobe vfio-pci
    echo "1002 73ff" > /sys/bus/pci/drivers/vfio-pci/new_id

    echo "Binding GPU audio to vfio-pci driver..."
    echo "1002 ab28" > /sys/bus/pci/drivers/vfio-pci/new_id

    echo "Rescanning PCI bus..."
    echo 1 > /sys/bus/pci/rescan
}

check_sudo

detach_gpu

echo "Starting the macOS VM..."

MY_OPTIONS="+ssse3,+sse4.2,+popcnt,+avx,+aes,+xsave,+xsaveopt,check"

ALLOCATED_RAM="8192" # MiB
CPU_SOCKETS="1"
CPU_CORES="4"
CPU_THREADS="8"

REPO_PATH="."
OVMF_DIR="."
GPU_ROM_FILE="./RX6600.rom"


# shellcheck disable=SC2054
args=(
  -enable-kvm -m "$ALLOCATED_RAM" -cpu Penryn,kvm=on,vendor=GenuineIntel,+invtsc,vmware-cpuid-freq=on,"$MY_OPTIONS"
  -machine q35
  -device qemu-xhci,id=xhci
  -device usb-kbd,bus=xhci.0 -device usb-tablet,bus=xhci.0
  -smp "$CPU_THREADS",cores="$CPU_CORES",sockets="$CPU_SOCKETS"
  -device vfio-pci,host=0d:00.0,multifunction=on,x-vga=on,romfile="$GPU_ROM_FILE"
  -device vfio-pci,host=0d:00.1
  -device isa-applesmc,osk="ourhardworkbythesewordsguardedpleasedontsteal(c)AppleComputerInc"
  -drive if=pflash,format=raw,readonly=on,file="$REPO_PATH/$OVMF_DIR/OVMF_CODE.fd"
  -drive if=pflash,format=raw,file="$REPO_PATH/$OVMF_DIR/OVMF_VARS-1920x1080.fd"
  -smbios type=2
  -device ich9-intel-hda -device hda-duplex
  -device ich9-ahci,id=sata
  -drive id=OpenCoreBoot,if=none,snapshot=on,format=qcow2,file="$REPO_PATH/OpenCore/OpenCore.qcow2"
  -device ide-hd,bus=sata.2,drive=OpenCoreBoot
  -device ide-hd,bus=sata.3,drive=InstallMedia
  -drive id=InstallMedia,if=none,file="$REPO_PATH/BaseSystem.img",format=raw
  -drive id=MacHDD,if=none,file="$REPO_PATH/mac_hdd_ng.img",format=qcow2
  -device ide-hd,bus=sata.4,drive=MacHDD
  -netdev user,id=net0,hostfwd=tcp::2222-:22 -device virtio-net-pci,netdev=net0,id=net0,mac=52:54:00:c9:18:27
  -monitor telnet:127.0.0.1:55555,server,nowait
  -monitor stdio
  -global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off
)

qemu-system-x86_64 "${args[@]}"