mal run script for running low-level code within qemu/kvm

run.sh

#!/bin/bash
(
    sleep 0.1
    while ! exec 3<> /dev/tcp/localhost/21118; do
        sleep 0.1
    done
    while read -u 3 -r cmd arg1; do
        case ${cmd} in
        slurp:)
            if [ -r "${arg1}" ]; then 
                echo "fdata: $(stat --printf="%s" ${arg1})" >&3
                cat >&3 ${arg1} 
            else
                echo "error: Could not read file ${arg1}" >&3
            fi
            ;;
        *)
            echo >&2 "Unknown socket command: $cmd"
            ;;
        esac
    done
) &
kvm -nographic \
    -monitor none \
    -serial stdio \ 
    -serial tcp:localhost:21118,server \
    -device isa-debug-exit,iobase=0xf4,iosize=0x04 \
    -cdrom $(dirname $0)/${STEP:-stepA_mal}.iso
exit $(( $? / 2 ))