run.sh

#!/bin/sh

FILESYSTEM_HEAD="build/head.bin"
FILESYSTEM="build/filesystem.bin"
OS_FILE="build/os.img"

die() { echo "$*" 1>&2 ; exit 1; }

filesize_in_sectors() {
    SIZE_IN_BYTES=0
    if [[ "$OSTYPE" == "linux-gnu" ]]; then
        SIZE_IN_BYTES=$(wc -c < $1)
    elif [[ "$OSTYPE" == "darwin"* ]]; then
        SIZE_IN_BYTES=$(stat -f %z $1)
    fi
    echo $((SIZE_IN_BYTES / 512))
}

attach_kernel() {
    RESEREVED_SECTORS=$(filesize_in_sectors $FILESYSTEM_HEAD)
    cat $FILESYSTEM_HEAD > $OS_FILE
    dd if=$FILESYSTEM of=$OS_FILE count=1 bs=90 conv=notrunc 2> /dev/null
    dd if=$FILESYSTEM skip=$RESEREVED_SECTORS bs=512 >> $OS_FILE 2> /dev/null
}

create_filesystem() {
    # Unmounting
    (sudo umount /mnt || true) 2> /dev/null

    # Creating empty disk image with a size of 5mb
    dd if=/dev/zero of=$FILESYSTEM bs=$BLOCK_SIZE count=50 2> /dev/null
    
    # Getting the size of FILESYSTEM_HEAD
    RESEREVED_SECTORS=$(filesize_in_sectors $FILESYSTEM_HEAD)
    
    export PATH=/sbin:$PATH
    # Creating an empty Fat32 filesystem
    mkfs.fat -F 32 -R $RESEREVED_SECTORS $FILESYSTEM > /dev/null

    mkdir -p build/isofiles

    # Generating binary files and adding them to `build/isofiles`` folder
    make filesystem
    success=$?

    if [ $success -ne 2 ]; then
        # Mounting the file and copying files to it
        if [[ "$OSTYPE" == "linux-gnu" ]]; then
            sudo mount -o loop $FILESYSTEM /mnt
            sudo cp -r build/isofiles/. /mnt
        elif [[ "$OSTYPE" == "darwin"* ]]; then
            MOUNT_POINT=$(hdiutil attach -imagekey diskimage-class=CRawDiskImage -nomount $FILESYSTEM)
            echo "Mounting $FILESYSTEM to $MOUNT_POINT"
            sudo mount -t msdos $MOUNT_POINT /mnt
            sudo cp -r build/isofiles/. /mnt
            hdiutil detach $MOUNT_POINT > /dev/null
        fi
        # Unmounting
        (sudo umount /mnt || true) 2> /dev/null
        rm -r build/isofiles

        return 1
    else
        return 2
    fi
}

run() {
    BLOCK_SIZE=0
    LD=0
    if [[ "$OSTYPE" == "linux-gnu" ]]; then
        BLOCK_SIZE="1M"
        LD="ld"
    elif [[ "$OSTYPE" == "darwin"* ]]; then
        BLOCK_SIZE="1m"
        LD="i686-elf-ld"
    fi

    echo "Compiling Kernel and Bootloader..."
    # Compiling bootloader and kernel into a single file
    make head LD=$LD
    success=$?
    
    echo "Creating filesystem."
    # Creating a filesystem Fat32 file with reserved sectors the size of the bootloader+kernel
    create_filesystem
    success2=$?

    # If there is no error in compiling the kernel
    if [ $success -ne 2 ] && [ $success2 -ne 2 ]; then
        echo "Compiled Kernel and Bootloader..."
        echo "Created filesystem."
        echo "Attaching kernel."
        # Attaching the kernel to the filesystem file
        attach_kernel
        echo "Kernel attached."
        echo "Running operating system."
        # Running
        qemu-system-i386 -drive file=$OS_FILE,format=raw -monitor stdio # -d int
    fi
}

run