I add that I placed iso image in a vfat partition.
And after, in terminal:
modprobe vfat
mkdir /mnt/source
mount -t vfat /dev/sd?? /mnt/source
I can see iso image there but when I try mounting it through a loop device:
mount -o loop /mnt/source/image.iso /cdrom
it fails so installation cannot go on.
It seems this second need was already reported in 785512 bug:
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Salutacions...Josep
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