scripts/gen_initramfs_list.sh

   1 #!/bin/bash
   2 # Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
   3 # Released under the terms of the GNU GPL
   4 #
   5 # Generate a newline separated list of entries from the file/directory
   6 # supplied as an argument.
   7 #
   8 # If a file/directory is not supplied then generate a small dummy file.
   9 #
  10 # The output is suitable for gen_init_cpio built from usr/gen_init_cpio.c.
  11 #
  12
  13 default_initramfs() {
  14         cat <<-EOF
  15                 # This is a very simple, default initramfs
  16
  17                 dir /dev 0755 0 0
  18                 nod /dev/console 0600 0 0 c 5 1
  19                 dir /root 0700 0 0
  20         EOF
  21 }
  22
  23 filetype() {
  24         local argv1="$1"
  25
  26         # symlink test must come before file test
  27         if [ -L "${argv1}" ]; then
  28                 echo "slink"
  29         elif [ -f "${argv1}" ]; then
  30                 echo "file"
  31         elif [ -d "${argv1}" ]; then
  32                 echo "dir"
  33         elif [ -b "${argv1}" -o -c "${argv1}" ]; then
  34                 echo "nod"
  35         elif [ -p "${argv1}" ]; then
  36                 echo "pipe"
  37         elif [ -S "${argv1}" ]; then
  38                 echo "sock"
  39         else
  40                 echo "invalid"
  41         fi
  42         return 0
  43 }
  44
  45 print_mtime() {
  46         local argv1="$1"
  47         local my_mtime="0"
  48
  49         if [ -e "${argv1}" ]; then
  50                 my_mtime=$(find "${argv1}" -printf "%T@\n" | sort -r | head -n 1)
  51         fi
  52
  53         echo "# Last modified: ${my_mtime}"
  54         echo
  55 }
  56
  57 parse() {
  58         local location="$1"
  59         local name="${location/${srcdir}//}"
  60         # change '//' into '/'
  61         name="${name//\/\///}"
  62         local mode="$2"
  63         local uid="$3"
  64         local gid="$4"
  65         local ftype=$(filetype "${location}")
  66         # remap uid/gid to 0 if necessary
  67         [ "$uid" -eq "$root_uid" ] && uid=0
  68         [ "$gid" -eq "$root_gid" ] && gid=0
  69         local str="${mode} ${uid} ${gid}"
  70
  71         [ "${ftype}" == "invalid" ] && return 0
  72         [ "${location}" == "${srcdir}" ] && return 0
  73
  74         case "${ftype}" in
  75                 "file")
  76                         str="${ftype} ${name} ${location} ${str}"
  77                         ;;
  78                 "nod")
  79                         local dev_type=
  80                         local maj=$(LC_ALL=C ls -l "${location}" | \
  81                                         gawk '{sub(/,/, "", $5); print $5}')
  82                         local min=$(LC_ALL=C ls -l "${location}" | \
  83                                         gawk '{print $6}')
  84
  85                         if [ -b "${location}" ]; then
  86                                 dev_type="b"
  87                         else
  88                                 dev_type="c"
  89                         fi
  90                         str="${ftype} ${name} ${str} ${dev_type} ${maj} ${min}"
  91                         ;;
  92                 "slink")
  93                         local target=$(LC_ALL=C ls -l "${location}" | \
  94                                         gawk '{print $11}')
  95                         str="${ftype} ${name} ${target} ${str}"
  96                         ;;
  97                 *)
  98                         str="${ftype} ${name} ${str}"
  99                         ;;
 100         esac
 101
 102         echo "${str}"
 103
 104         return 0
 105 }
 106
 107 usage() {
 108         printf    "Usage:\n"
 109         printf    "$0 [ [-u <root_uid>] [-g <root_gid>] [-d | <cpio_source>] ] . . .\n"
 110         printf    "\n"
 111         printf -- "-u <root_uid>  User ID to map to user ID 0 (root).\n"
 112         printf    "               <root_uid> is only meaningful if <cpio_source>\n"
 113         printf    "               is a directory.\n"
 114         printf -- "-g <root_gid>  Group ID to map to group ID 0 (root).\n"
 115         printf    "               <root_gid> is only meaningful if <cpio_source>\n"
 116         printf    "               is a directory.\n"
 117         printf    "<cpio_source>  File list or directory for cpio archive.\n"
 118         printf    "               If <cpio_source> is not provided then a\n"
 119         printf    "               a default list will be output.\n"
 120         printf -- "-d             Output the default cpio list.  If no <cpio_source>\n"
 121         printf    "               is given then the default cpio list will be output.\n"
 122         printf    "\n"
 123         printf    "All options may be repeated and are interpreted sequentially\n"
 124         printf    "and immediately.  -u and -g states are preserved across\n"
 125         printf    "<cpio_source> options so an explicit \"-u 0 -g 0\" is required\n"
 126         printf    "to reset the root/group mapping.\n"
 127 }
 128
 129 build_list() {
 130         printf "\n#####################\n# $cpio_source\n"
 131
 132         if [ -f "$cpio_source" ]; then
 133                 print_mtime "$cpio_source"
 134                 cat "$cpio_source"
 135         elif [ -d "$cpio_source" ]; then
 136                 srcdir=$(echo "$cpio_source" | sed -e 's://*:/:g')
 137                 dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" 2>/dev/null)
 138
 139                 # If $dirlist is only one line, then the directory is empty
 140                 if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
 141                         print_mtime "$cpio_source"
 142
 143                         echo "${dirlist}" | \
 144                         while read x; do
 145                                 parse ${x}
 146                         done
 147                 else
 148                         # Failsafe in case directory is empty
 149                         default_initramfs
 150                 fi
 151         else
 152                 echo "  $0: Cannot open '$cpio_source'" >&2
 153                 exit 1
 154         fi
 155 }
 156
 157
 158 root_uid=0
 159 root_gid=0
 160
 161 while [ $# -gt 0 ]; do
 162         arg="$1"
 163         shift
 164         case "$arg" in
 165                 "-u")
 166                         root_uid="$1"
 167                         shift
 168                         ;;
 169                 "-g")
 170                         root_gid="$1"
 171                         shift
 172                         ;;
 173                 "-d")
 174                         default_list="$arg"
 175                         default_initramfs
 176                         ;;
 177                 "-h")
 178                         usage
 179                         exit 0
 180                         ;;
 181                 *)
 182                         case "$arg" in
 183                                 "-"*)
 184                                         printf "ERROR: unknown option \"$arg\"\n" >&2
 185                                         printf "If the filename validly begins with '-', then it must be prefixed\n" >&2
 186                                         printf "by './' so that it won't be interpreted as an option." >&2
 187                                         printf "\n" >&2
 188                                         usage >&2
 189                                         exit 1
 190                                         ;;
 191                                 *)
 192                                         cpio_source="$arg"
 193                                         build_list
 194                                         ;;
 195                         esac
 196                         ;;
 197         esac
 198 done
 199
 200 # spit out the default cpio list if a source hasn't been specified
 201 [ -z "$cpio_source" -a -z "$default_list" ] && default_initramfs
 202
 203 exit 0