A script to create MAME-compatible FAT32 disk image for the Foenix F256 on a Mac

f256-disk-image.sh

#!/bin/bash

if [ "$#" -lt 2 ]; then
    echo "Usage: $0 [-q] <disk_name> <size_in_mb>"
    exit 1
fi

QUIET=false
while getopts "q" opt; do
	case $opt in
		q) QUIET=true ;;
		*) ;;
	esac
done

shift $((OPTIND - 1))
DISK_NAME=$1
SIZE_MB=$2
IMG_FILE="${DISK_NAME}.img"
IMG_PATH="$(pwd)/$IMG_FILE"

abort () {
	if ! $QUIET; then
		command echo "❌ $@"
	else
		command echo "[ERROR] $@"
	fi
	exit 1
}

step () {
	if ! $QUIET; then
		command echo "➜ $@"
	fi
}

if [[ -e "$IMG_FILE" ]]; then
	if ! $QUIET; then
		read -p "The file '$IMG_FILE' already exists. Do you want to override it? [n] " CHOICE
		CHOICE="${CHOICE:-n}"
		if [[ "$CHOICE" != "y" ]]; then
			abort "File already exists, aborted"
		fi
	else
		abort "File already exists, aborted"
	fi

	if hdiutil info | grep -q "$IMG_FILE"; then
		abort "Disk image '$IMG_FILE' is currently mounted. Please unmount it first."
	fi
fi

if [ "$SIZE_MB" -lt 34 ]; then
	abort "FAT32 requires a disk size of at least 34MB (32MB + partition table)."
fi

step "Creating a raw ${SIZE_MB}MB disk image '$IMG_FILE'"
OUT=$(dd if=/dev/zero of=$IMG_FILE bs=1M count=$SIZE_MB 2>&1)
if [[ $? -ne 0 ]]; then
	abort "Failed to create disk image: $OUT"
fi

step "Attaching the raw disk image"
OUT=$(hdiutil attach -imagekey diskimage-class=CRawDiskImage -nomount $IMG_FILE 2>&1)
DEVICE=$(echo "$OUT" | head -n 1)
if [[ ! $DEVICE =~ "/dev/" ]]; then
    abort "Failed to attach disk image: $OUT"
fi
step "Disk image attached as $DEVICE"

detach () {
	hdiutil detach $DEVICE >/dev/null
}

step "Partitioning/formatting the disk"
OUT=$(diskutil partitionDisk $DEVICE MBR "MS-DOS FAT32" $DISK_NAME 100% 2>&1)
if [[ $? -ne 0 ]]; then
	detach
	abort "Failed to partition disk image: $(echo "$OUT" | tail -n 1)"
fi

step "Re-mounting the disk"
OUT=$(detach && hdiutil attach $IMG_FILE 2>&1)
if [[ $? -ne 0 ]]; then
	detach
	abort "Failed to mount the formatted disk: $OUT"
fi

VOLUME_INFO=$(echo "$OUT" | head -n 2 | tail -n 1)
read -ra VOLUME <<< "$VOLUME_INFO"
VOLUME_PATH="${VOLUME[2]}"

if ! $QUIET; then
	echo "✨ Mounted at $VOLUME_PATH ✨"
else
	echo "$VOLUME_PATH"
fi