This is what it is may be about, there is a directory on the mentioned rescue-kit. My full path to it (using the laptop) on the usb-drive is

Code:

/media/usb0/save

going down to

Code:

/usr/share/bug/grub-efi-amd64

that contains two files
named presubj as a simple textfile and
the funny named sript, a shell-sript. To be written down I pasted the code.

Code:

echo >&3
echo "*********************** BEGIN /proc/mdstat" >&3
cat /proc/mdstat >&3 2>&1 || true
echo "*********************** END /proc/mdstat" >&3

cat <<EOF
Information on any LVM volumes on this system is valuable to the GRUB
developers, but gathering this information requires the root password.
EOF
yesno "Do you want to provide LVM volume information?" nop
if [ "$REPLY" = yep ]; then
  echo >&3
  echo "*********************** BEGIN LVM" >&3
  su root -c "vgdisplay; pvdisplay; lvdisplay" >&3
  echo "*********************** END LVM" >&3
fi

echo >&3
echo "*********************** BEGIN /dev/disk/by-id" >&3
ls -l /dev/disk/by-id >&3 2>&1 || true
echo "*********************** END /dev/disk/by-id" >&3

echo >&3
echo "*********************** BEGIN /dev/disk/by-uuid" >&3
ls -l /dev/disk/by-uuid >&3 2>&1 || true
echo "*********************** END /dev/disk/by-uuid" >&3

exit 0

From stackoverflow.com
there is another hint
How can a Bootloader written in x86 Assembly be written to a USB Flash drive and support both BIOS and UEFI? - Stack Overflow

quote
"Removable media does not need to be GPT formatted in order for UEFI to boot from it. You need to create efi/boot folder on a FAT partition on a removable medium and place your UEFI bootloader there. File name must be bootx64.efi for X86-64 architecture. Booting in Legacy or BIOS mode will be handled without changes - via MBR. In pure UEFI boot mode it will read /efi/boot/bootx64.efi file.
Please note also, that FAT partition should be addressed by the first MBR partition entry and be active."

So right now I guessing what file to put down in this bootable directory?
The cited shell-script up above to rename it, file size is 1.7 kb or a file named
"boot.catalog" with a flie size of 2 kb but this is an unknown file (application/octet-stream)?
Any hints?

BTW coming back to the very outset ot this thread, there must be a hard link set by wheezy or system.d, because any usb-stick that once has been in touch whith wheezy only works properly on squeeze, when I type as root in the terminal

Code:

/umount/usb0

otherwise I am forced to work
a bit more complicated to copy files, just like

Code:

 stat %A filname

and afterwards

Code:

cp filename /media/foo

I am aware there is jessie burning up the charts.