Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 1 | #!/bin/sh |
| 2 | |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 3 | fslist="proc sys dev run" |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 4 | rodir=run/initramfs/ro |
| 5 | rwdir=run/initramfs/rw |
| 6 | upper=$rwdir/cow |
| 7 | work=$rwdir/work |
| 8 | |
| 9 | cd / |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 10 | mkdir -p $fslist |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 11 | mount dev dev -tdevtmpfs |
| 12 | mount sys sys -tsysfs |
| 13 | mount proc proc -tproc |
| 14 | if ! grep run proc/mounts |
| 15 | then |
| 16 | mount tmpfs run -t tmpfs -o mode=755,nodev |
| 17 | fi |
| 18 | |
| 19 | mkdir -p $rodir $rwdir |
| 20 | |
| 21 | cp -rp init shutdown update whitelist bin sbin usr lib etc var run/initramfs |
| 22 | |
| 23 | # To start a interactive shell with job control at this point, run |
| 24 | # getty 38400 ttyS4 |
| 25 | |
| 26 | findmtd() { |
| 27 | m=$(grep -xl "$1" /sys/class/mtd/*/name) |
| 28 | m=${m%/name} |
| 29 | m=${m##*/} |
| 30 | echo $m |
| 31 | } |
| 32 | |
Milton D. Miller II | 8084d74 | 2016-01-27 20:18:16 -0600 | [diff] [blame] | 33 | env=$(findmtd u-boot-env) |
| 34 | if test -n $env |
| 35 | then |
| 36 | ln -s /dev/$env /run/mtd:u-boot-env |
| 37 | cp /run/mtd:u-boot-env /run/fw_env |
| 38 | fi |
| 39 | |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 40 | rofs=$(findmtd rofs) |
| 41 | rwfs=$(findmtd rwfs) |
| 42 | |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 43 | rodev=/dev/mtdblock${rofs#mtd} |
| 44 | rwdev=/dev/mtdblock${rwfs#mtd} |
| 45 | |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 46 | rofst=squashfs |
| 47 | rwfst=ext4 |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 48 | roopts=ro |
| 49 | rwopts=rw |
| 50 | |
| 51 | init=/sbin/init |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 52 | |
| 53 | echo rofs = $rofs $rofst rwfs = $rwfs $rwfst |
| 54 | |
| 55 | if grep -w debug-init-sh /proc/cmdline || |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 56 | ! mount $rwdev $rwdir -t $rwfst -o $rwopts |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 57 | then |
| 58 | echo Please mount the rw file system on $rwdir from this shell |
| 59 | while ! sulogin && ! test -f /takeover |
| 60 | do |
| 61 | echo getty failed, retrying |
| 62 | done |
| 63 | fi |
| 64 | |
| 65 | # Touch /takeover in the above getty to become pid 1 |
| 66 | if test -e /takeover |
| 67 | then |
| 68 | export PS1=init#\ |
| 69 | exec /bin/sh |
| 70 | fi |
| 71 | |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 72 | mount $rodev $rodir -t $rofst -o $roopts |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 73 | |
| 74 | rm -rf $work |
| 75 | mkdir -p $upper |
| 76 | mkdir -p $work |
| 77 | |
| 78 | mount -t overlay -o lowerdir=$rodir,upperdir=$upper,workdir=$work cow /root |
| 79 | |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 80 | if ! chroot /root /bin/sh -c "test -x '$init' -a -s '$init'" |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 81 | then |
Milton Miller | 016e0df | 2016-02-05 11:06:39 -0600 | [diff] [blame] | 82 | echo "Unable to confirm /sbin/init is an executable non-empty file." |
| 83 | echo "Change Root test failed! Invoking emergency shell." |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 84 | PS1=rescue#\ sulogin |
| 85 | fi |
| 86 | |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 87 | for f in $fslist |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 88 | do |
| 89 | mount --move $f root/$f |
| 90 | done |
| 91 | |
Milton Miller | ba65b7b | 2016-02-05 12:07:53 -0600 | [diff] [blame^] | 92 | # switch_root /root $init |
| 93 | exec chroot /root $init |
Milton D. Miller II | 0e77514 | 2016-01-20 14:57:54 -0600 | [diff] [blame] | 94 | |