# qemu-args.sh -- the demo machine, sourced by make-snapshot.sh and start-session.sh.
#
# A session resumes a machine saved by make-snapshot.sh, and QEMU can resume a saved machine only
# into the same machine: the same board, CPU, memory, firmware and devices. Both scripts build the
# command line here, so they cannot drift apart. It is the machine `make -f kernel/Makefile
# ARCH=amd64 qemu` boots (q35, TCG, 1 GiB, OVMF, the ISO as a CD), less what a visitor must not
# have: no network device, no Artemis disk, no display, and QEMU's seccomp sandbox on.
#
#   demo_qemu_args <state-dir> <vars.fd>   -> fills the array QEMU_ARGS
#
# <state-dir>/StarshipOS.iso is the image; <state-dir>/identity.img, if there, is the identity
# drive every session gets (issue #111), attached with its writes discarded.

OVMF_CODE=${OVMF_CODE:-/usr/share/OVMF/OVMF_CODE_4M.fd}

demo_qemu_args() {
    local dir=$1 vars=$2
    QEMU_ARGS=(
        -machine q35,accel=tcg
        -cpu qemu64,+rdrand
        -m 1024
        -smp 1
        -drive "if=pflash,format=raw,readonly=on,file=$OVMF_CODE"
        -drive "if=pflash,format=raw,file=$vars"
        -drive "if=none,id=cd,media=cdrom,readonly=on,file=$dir/StarshipOS.iso"
        -device ide-cd,drive=cd,bootindex=0
        -device qemu-xhci,id=xhci0,p2=16,p3=16   # kernel/Makefile XHCI_PORTS
        -nic none
        -display none
        -no-reboot
        -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny
    )
    if [ -f "$dir/identity.img" ]; then
        QEMU_ARGS+=(-drive "if=none,id=ident,format=raw,snapshot=on,file=$dir/identity.img"
                    -device usb-storage,bus=xhci0.0,port=1,drive=ident)
    fi
}