1 # Pseudo file example 2 3 # Mksquashfs supports pseudo files, these allow fake files, directories, 4 # character and block devices to be specified and added to the Squashfs 5 # filesystem being built, rather than requiring them to be present in the 6 # source directories. 7 # 8 # This, for example, allows device nodes to be added to the filesystem without 9 # requiring root access. 10 11 # Mksquashfs 4.1 adds support for "dynamic pseudo files" and a modify operation. 12 # Dynamic pseudo files allow files to be dynamically created when Mksquashfs 13 # is run, their contents being the result of running a command or piece of 14 # shell script. The modifiy operation allows the mode/uid/gid of an existing 15 # file in the source filesystem to be modified. 16 17 # Two Mksquashfs options are supported, -p allows one pseudo file to be 18 # specified #on the command line, and -pf allows a pseudo file to be specified 19 # containing a list of pseduo definitions, one per line. 20 21 # Pseudo file examples 22 # Run mkquashfs . /tmp/img -pf pseudo-file.examples 23 # to see their effect 24 25 # Creating dynamic file examples 26 27 # Create a file "dmesg" containing the output from dmesg. 28 dmesg f 444 root root dmesg 29 30 31 # Create a file RELEASE containing the release name, date, build host, and 32 # an incrementing version number. The incrementing version is a side-effect 33 # of executing the shell script, and ensures every time Mksquashfs is run a 34 # new version number is used without requiring any other shell scripting. 35 RELEASE f 444 root root \ 36 if [ ! -e /tmp/ver ]; then \ 37 echo 0 > /tmp/ver; \ 38 fi; \ 39 ver=`cat /tmp/ver`; \ 40 ver=$((ver +1)); \ 41 echo $ver > /tmp/ver; \ 42 echo -n "release x.x"; \ 43 echo "-dev #"$ver `date` "Build host" `hostname` 44 45 46 # Copy 10K from the device /dev/sda1 into the file input. Ordinarily 47 # Mksquashfs given a device, fifo, or named socket will place that special file 48 # within the Squashfs filesystem, this allows input from these special 49 # files to be captured and placed in the Squashfs filesystem. 50 input f 444 root root dd if=/dev/sda1 bs=1024 count=10 51 52 53 # Creating a block or character device examples 54 55 # Create a character device "chr_dev" with major:minor 100:1 and 56 # a block device "blk_dev" with major:minor 200:200, both with root 57 # uid/gid and a mode of rw-rw-rw. 58 chr_dev c 666 root root 100 1 59 blk_dev b 666 0 0 200 200 60 61 62 # Creating a directory example 63 64 # create a directory "pseudo_dir" with root uid/gid and mode of r--r--r--. 65 pseudo_dir d 444 root root 66 67 68 # Modifying attributes of an existing file exmaple 69 70 # Change the attributes of the file "INSTALL" in the filesystem to have 71 # root uid/gid and a mode of rw-rw-rw, overriding the attributes obtained 72 # from the source filesystem. 73 INSTALL m 666 root root 74 75
