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

   1 #!/bin/sh
   2 # Copyright (C) 2006-2013 OpenWrt.org
   3 # Copyright (C) 2010 Vertical Communications
   4
   5 boot_hook_splice_start() {
   6         export -n PI_HOOK_SPLICE=1
   7 }
   8
   9 boot_hook_splice_finish() {
  10         local hook
  11         for hook in $PI_STACK_LIST; do
  12                 local v; eval "v=\${${hook}_splice:+\$${hook}_splice }$hook"
  13                 export -n "${hook}=${v% }"
  14                 export -n "${hook}_splice="
  15         done
  16         export -n PI_HOOK_SPLICE=
  17 }
  18
  19 boot_hook_init() {
  20         local hook="${1}_hook"
  21         export -n "PI_STACK_LIST=${PI_STACK_LIST:+$PI_STACK_LIST }$hook"
  22         export -n "$hook="
  23 }
  24
  25 boot_hook_add() {
  26         local hook="${1}_hook${PI_HOOK_SPLICE:+_splice}"
  27         local func="${2}"
  28
  29         [ -n "$func" ] && {
  30                 local v; eval "v=\$$hook"
  31                 export -n "$hook=${v:+$v }$func"
  32         }
  33 }
  34
  35 boot_hook_shift() {
  36         local hook="${1}_hook"
  37         local rvar="${2}"
  38
  39         local v; eval "v=\$$hook"
  40         [ -n "$v" ] && {
  41                 local first="${v%% *}"
  42
  43                 [ "$v" != "${v#* }" ] && \
  44                         export -n "$hook=${v#* }" || \
  45                         export -n "$hook="
  46
  47                 export -n "$rvar=$first"
  48                 return 0
  49         }
  50
  51         return 1
  52 }
  53
  54 boot_run_hook() {
  55         local hook="$1"
  56         local func
  57
  58         while boot_hook_shift "$hook" func; do
  59                 local ran; eval "ran=\$PI_RAN_$func"
  60                 [ -n "$ran" ] || {
  61                         export -n "PI_RAN_$func=1"
  62                         $func "$1" "$2"
  63                 }
  64         done
  65 }
  66
  67 pivot() { # <new_root> <old_root>
  68         /bin/mount -o noatime,move /proc $1/proc && \
  69         pivot_root $1 $1$2 && {
  70                 /bin/mount -o noatime,move $2/dev /dev
  71                 /bin/mount -o noatime,move $2/tmp /tmp
  72                 /bin/mount -o noatime,move $2/sys /sys 2>&-
  73                 /bin/mount -o noatime,move $2/overlay /overlay 2>&-
  74                 return 0
  75         }
  76 }
  77
  78 fopivot() { # <rw_root> <work_dir> <ro_root> <dupe?>
  79         /bin/mount -o noatime,lowerdir=/,upperdir=$1,workdir=$2 -t overlay "overlayfs:$1" /mnt
  80         pivot /mnt $3
  81 }
  82
  83 ramoverlay() {
  84         mkdir -p /tmp/root
  85         /bin/mount -t tmpfs -o noatime,mode=0755 root /tmp/root
  86         mkdir -p /tmp/root/root /tmp/root/work
  87         fopivot /tmp/root/root /tmp/root/work /rom 1
  88 }