feat: Make machine type selectable (#415)

src/config.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 set -Eeuo pipefail
 
+: "${MACHINE:="q35"}"
 : "${USB:="qemu-xhci"}"
 : "${SERIAL:="mon:stdio"}"
 : "${MONITOR:="telnet:localhost:7100,server,nowait,nodelay"}"
@@ -11,7 +12,7 @@ MON_OPTS="-monitor $MONITOR"
 USB_OPTS="-device $USB -device usb-tablet"
 RAM_OPTS=$(echo "-m $RAM_SIZE" | sed 's/MB/M/g;s/GB/G/g;s/TB/T/g')
 CPU_OPTS="-cpu $CPU_FLAGS -smp $CPU_CORES,sockets=1,dies=1,cores=$CPU_CORES,threads=1"
-MAC_OPTS="-machine type=q35${SECURE},graphics=off,vmport=off,dump-guest-core=off,hpet=off${KVM_OPTS}"
+MAC_OPTS="-machine type=${MACHINE}${SECURE},graphics=off,vmport=off,dump-guest-core=off,hpet=off${KVM_OPTS}"
 DEV_OPTS="-device virtio-balloon-pci,id=balloon0,bus=pcie.0,addr=0x4"
 DEV_OPTS="$DEV_OPTS -object rng-random,id=objrng0,filename=/dev/urandom"
 DEV_OPTS="$DEV_OPTS -device virtio-rng-pci,rng=objrng0,id=rng0,bus=pcie.0,addr=0x1c"