package/base-files/files/lib/functions/preinit.sh

   1 # Copyright (C) 2006-2013 OpenWrt.org
   2 # Copyright (C) 2010 Vertical Communications
   3
   4 boot_hook_splice_start() {
   5         export -n PI_HOOK_SPLICE=1
   6 }
   7
   8 boot_hook_splice_finish() {
   9         local hook
  10         for hook in $PI_STACK_LIST; do
  11                 local v; eval "v=\${${hook}_splice:+\$${hook}_splice }$hook"
  12                 export -n "${hook}=${v% }"
  13                 export -n "${hook}_splice="
  14         done
  15         export -n PI_HOOK_SPLICE=
  16 }
  17
  18 boot_hook_init() {
  19         local hook="${1}_hook"
  20         export -n "PI_STACK_LIST=${PI_STACK_LIST:+$PI_STACK_LIST }$hook"
  21         export -n "$hook="
  22 }
  23
  24 boot_hook_add() {
  25         local hook="${1}_hook${PI_HOOK_SPLICE:+_splice}"
  26         local func="${2}"
  27
  28         [ -n "$func" ] && {
  29                 local v; eval "v=\$$hook"
  30                 export -n "$hook=${v:+$v }$func"
  31         }
  32 }
  33
  34 boot_hook_shift() {
  35         local hook="${1}_hook"
  36         local rvar="${2}"
  37
  38         local v; eval "v=\$$hook"
  39         [ -n "$v" ] && {
  40                 local first="${v%% *}"
  41
  42                 [ "$v" != "${v#* }" ] && \
  43                         export -n "$hook=${v#* }" || \
  44                         export -n "$hook="
  45
  46                 export -n "$rvar=$first"
  47                 return 0
  48         }
  49
  50         return 1
  51 }
  52
  53 boot_run_hook() {
  54         local hook="$1"
  55         local func
  56
  57         while boot_hook_shift "$hook" func; do
  58                 local ran; eval "ran=\$PI_RAN_$func"
  59                 [ -n "$ran" ] || {
  60                         export -n "PI_RAN_$func=1"
  61                         $func "$1" "$2"
  62                 }
  63         done
  64 }
  65
  66 pivot() { # <new_root> <old_root>
  67         /bin/mount -o noatime,move /proc $1/proc && \
  68         pivot_root $1 $1$2 && {
  69                 /bin/mount -o noatime,move $2/dev /dev
  70                 /bin/mount -o noatime,move $2/tmp /tmp
  71                 /bin/mount -o noatime,move $2/sys /sys 2>&-
  72                 /bin/mount -o noatime,move $2/overlay /overlay 2>&-
  73                 return 0
  74         }
  75 }
  76
  77 fopivot() { # <rw_root> <work_dir> <ro_root> <dupe?>
  78         /bin/mount -o noatime,lowerdir=/,upperdir=$1,workdir=$2 -t overlay "overlayfs:$1" /mnt
  79         pivot /mnt $3
  80 }
  81
  82 ramoverlay() {
  83         mkdir -p /tmp/root
  84         /bin/mount -t tmpfs -o noatime,mode=0755 root /tmp/root
  85         mkdir -p /tmp/root/root /tmp/root/work
  86         fopivot /tmp/root/root /tmp/root/work /rom 1
  87 }