/lib/partman/valid_filesystems/80fat is in ubiquity 2.21.63.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | #!/bin/sh
dev=$1
id=$2
property=$3
[ -f /var/lib/partman/vfat ] || exit 0
case $property in
formatable)
if search-path mkfs.fat || search-path mkdosfs; then
echo fat16
echo fat32
fi
;;
existing)
[ -f $id/detected_filesystem ] || exit 0
fs=$(cat $id/detected_filesystem)
case "$fs" in
fat16)
echo fat16
;;
fat32)
echo fat32
;;
esac
;;
esac
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