/usr/src/linux-source-3.13.0/debian.master/d-i/exclude-firmware.armhf-generic is in linux-source-3.13.0 3.13.0-86.131.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | nic-modules
scsi-modules
|