local command_name="$1"

local install_hint="$2"

if ! command -v "$command_name" >/dev/null 2>&1; then

echo "✗ Required command not found: ${command_name}" >&2

echo " ${install_hint}" >&2

exit 1

fi

local clean_build=false

if [[ $# -gt 1 ]]; then

print_usage >&2

exit 1

fi

if [[ $# -eq 1 ]]; then

case "$1" in

--clean)

clean_build=true

;;

-h|--help)

print_usage

exit 0

;;

*)

print_usage >&2

exit 1

;;

esac

fi

echo "Building ThunderOS kernel..."

require_command mkfs.ext2 "Install e2fsprogs: sudo apt-get install e2fsprogs"

if [[ "${clean_build}" == true ]]; then

make clean

fi

make all

if [[ ! -f "${KERNEL_ELF}" ]]; then

echo "✗ Build failed" >&2

exit 1

fi

echo ""

echo "✓ Kernel built successfully"

echo " Binary: ${KERNEL_ELF}"

# Create ext2 filesystem image

echo ""

echo "Creating ext2 filesystem image (${FS_SIZE})..."

# Create temporary directory for filesystem contents (force clean)

rm -rf build/testfs

mkdir -m 755 build/testfs

mkdir -m 755 build/testfs/bin

# Add test files

echo "Hello from ThunderOS ext2 filesystem!" > build/testfs/test.txt

echo "This is a sample file for testing." > build/testfs/README.txt

# Build userland programs if available

if [[ -f "build_userland.sh" ]]; then

echo "Building userland programs..."

chmod +x build_userland.sh

./build_userland.sh

# Copy userland binaries if they exist

for prog in cat ls hello clock pwd mkdir rmdir touch rm clear sleep ush ps uname uptime whoami tty kill poweroff reboot; do

if [[ -f "external/userland/build/${prog}" ]]; then

cp "external/userland/build/${prog}" build/testfs/bin/

echo " Added /bin/${prog}"

fi

done

else

echo "✗ build_userland.sh not found" >&2

exit 1

fi

# Create ext2 filesystem

mkfs.ext2 -F -q -d build/testfs "${FS_IMG}" "${FS_SIZE}"

rm -rf build/testfs

if [[ ! -f "${FS_IMG}" ]]; then

echo "✗ Filesystem image was not created" >&2

exit 1

fi

echo "✓ Filesystem created: ${FS_IMG}"

echo " Size: $(du -h "${FS_IMG}" | cut -f1)"

echo ""

echo "Build complete! Run with:"

echo " ./run_os.sh"

echo ""

echo "Or manually with QEMU:"

echo " qemu-system-riscv64 -M virt -m 128M -nographic -serial mon:stdio \\"

echo " -bios none -kernel ${KERNEL_ELF} \\"

echo " -drive file=${FS_IMG},if=none,format=raw,id=hd0 \\"

echo " -device virtio-blk-device,drive=hd0 \\"

echo " -global virtio-mmio.force-legacy=false"