menuentry 'Arch Linux copytoram' {
        linux   /boot/test/vmlinuz-linux root=/dev/sda1
        initrd  /boot/test/initramfs-linux.img
}

HOOKS="base udev autodetect block filesystems"

# mkinitcpio preset file for the 'linux' package
ALL_config="/etc/mkinitcpio.conf"
ALL_kver="/boot/vmlinuz-linux"
PRESETS=('default')
default_image="/boot/test/initramfs-linux.img"

#!/bin/bash

build() {
 add_binary "/usr/bin/tar"
add_binary "/usr/bin/gzip"
    if (( fs_autodetect_failed )); then
        add_all_modules -f 'nls' '/kernel/fs'
    else
        add_checked_modules -f 'nls' '/kernel/fs'
    fi
}

<...>
default_mount_handler() {
    if [ ! -b "$root" ]; then
        err "Unable to find root device '$root'."
        echo "You are being dropped to a recovery shell"
        echo "    Type 'exit' to try and continue booting"
        launch_interactive_shell
        msg "Trying to continue (this will most likely fail) ..."
    fi

    msg ":: mounting '$root' on real root"
mkdir /ramboottmp
    if ! mount ${fstype:+-t $fstype} -o ${rwopt:-ro}${rootflags:+,$rootflags} "$root" /ramboottmp ; then
        echo "You are now being dropped into an emergency shell."
        launch_interactive_shell
        msg "Trying to continue (this will most likely fail) ..."
else
mount -t tmpfs -o size=100% none "$1"
cd "$1"
tar vzxf /ramboottmp/ram.tar.gz
umount /ramboottmp
fi
}
<...>

jim945
Только я не понял почему здесь разговор об образе пошел, если можно обойтись без него.

jim945
как сделано копирование образа в лайве арча. Конкретно copytoram