Milton D. Miller II | d89d5e0 | 2016-01-20 14:57:54 -0600 | [diff] [blame^] | 1 | #!/bin/sh |
| 2 | |
| 3 | rodir=run/initramfs/ro |
| 4 | rwdir=run/initramfs/rw |
| 5 | upper=$rwdir/cow |
| 6 | work=$rwdir/work |
| 7 | |
| 8 | cd / |
| 9 | mkdir -p sys proc dev run |
| 10 | mount dev dev -tdevtmpfs |
| 11 | mount sys sys -tsysfs |
| 12 | mount proc proc -tproc |
| 13 | if ! grep run proc/mounts |
| 14 | then |
| 15 | mount tmpfs run -t tmpfs -o mode=755,nodev |
| 16 | fi |
| 17 | |
| 18 | mkdir -p $rodir $rwdir |
| 19 | |
| 20 | cp -rp init shutdown update whitelist bin sbin usr lib etc var run/initramfs |
| 21 | |
| 22 | # To start a interactive shell with job control at this point, run |
| 23 | # getty 38400 ttyS4 |
| 24 | |
| 25 | findmtd() { |
| 26 | m=$(grep -xl "$1" /sys/class/mtd/*/name) |
| 27 | m=${m%/name} |
| 28 | m=${m##*/} |
| 29 | echo $m |
| 30 | } |
| 31 | |
| 32 | rofs=$(findmtd rofs) |
| 33 | rwfs=$(findmtd rwfs) |
| 34 | |
| 35 | rofst=squashfs |
| 36 | rwfst=ext4 |
| 37 | |
| 38 | echo rofs = $rofs $rofst rwfs = $rwfs $rwfst |
| 39 | |
| 40 | if grep -w debug-init-sh /proc/cmdline || |
| 41 | ! mount -o rw /dev/mtdblock${rwfs#mtd} $rwdir -t $rwfst |
| 42 | then |
| 43 | echo Please mount the rw file system on $rwdir from this shell |
| 44 | while ! sulogin && ! test -f /takeover |
| 45 | do |
| 46 | echo getty failed, retrying |
| 47 | done |
| 48 | fi |
| 49 | |
| 50 | # Touch /takeover in the above getty to become pid 1 |
| 51 | if test -e /takeover |
| 52 | then |
| 53 | export PS1=init#\ |
| 54 | exec /bin/sh |
| 55 | fi |
| 56 | |
| 57 | mount -o ro /dev/mtdblock${rofs#mtd} $rodir -t $rofst |
| 58 | |
| 59 | rm -rf $work |
| 60 | mkdir -p $upper |
| 61 | mkdir -p $work |
| 62 | |
| 63 | mount -t overlay -o lowerdir=$rodir,upperdir=$upper,workdir=$work cow /root |
| 64 | |
| 65 | if ! chroot /root /bin/sh -c exit |
| 66 | then |
| 67 | echo 'chroot test failed; invoking emergency shell.' |
| 68 | PS1=rescue#\ sulogin |
| 69 | fi |
| 70 | |
| 71 | for f in sys dev proc run |
| 72 | do |
| 73 | mount --move $f root/$f |
| 74 | done |
| 75 | |
| 76 | # switch_root /root /sbin/init |
| 77 | exec chroot /root /sbin/init |
| 78 | |