layerpie/lpie at master · Phaeilo/layerpie · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
#!/bin/sh

is_root()
{
    if [ $(id -u) -ne 0 ] ; then
        >&2 echo "must be root"
        exit 1
    fi
}

print_status()
{
    cat /proc/cmdline | grep " lpie" > /dev/null; A=$?
    cat /proc/mounts | grep "overlay / " > /dev/null; B=$?
    if [ $A -eq 0 -a $B -eq 0 ] ; then
        >&2 echo "filesystem mode: overlayfs"
    else
        >&2 echo "filesystem mode: rw"
    fi

    cat /boot/cmdline.txt | grep " lpie" > /dev/null
    if [ $? -eq 0 ] ; then
        >&2 echo "cmdline.txt: lpie enabled"
    else
        >&2 echo "cmdline.txt: lpie disabled"
    fi
}

change_cmdline()
{
    ENABLE=$1

    # change possible?
    cat /boot/cmdline.txt | grep " lpie" > /dev/null; X=$?
    if [ $X -eq 0 -a $ENABLE -eq 1 ] ; then
        >&2 echo "lpie already enabled"
        exit 1
    fi
    if [ $X -ne 0 -a $ENABLE -eq 0 ] ; then
        >&2 echo "lpie already disabled"
        exit 1
    fi

    # remount /boot, if necessary
    RO=0
    cat /proc/mounts | grep /boot | grep "\sro[\s,]" > /dev/null
    if [ $? -eq 0 ] ; then
        mount -o remount,rw /boot
        RO=1
    fi

    # update cmdline.txt
    if [ $ENABLE -eq 2 ] ; then
        # disable temporarily
        sed -i 's/ lpie//g' /boot/cmdline.txt
        sed -i 's/$/ tmp-rw-lpie/' /boot/cmdline.txt
    fi
    if [ $ENABLE -eq 1 ] ; then
        # enable permanently
        sed -i 's/$/ lpie/' /boot/cmdline.txt
    fi
    if [ $ENABLE -eq 0 ] ; then
        # disable permanently
        sed -i 's/ lpie//g' /boot/cmdline.txt
    fi

    # remount /boot, if necessary
    if [ $RO -eq 1 ] ; then
        mount -o remount,ro /boot
    fi

    if [ $ENABLE -eq 1 ] ; then
        >&2 echo "lpie enabled"
    fi
    if [ $ENABLE -eq 0 ] ; then
        >&2 echo "lpie disabled"
    fi
}

CMD=$1
case $CMD in
    status)
        print_status
        ;;
    enable)
        is_root
        change_cmdline 1
        ;;
    disable)
        is_root
        change_cmdline 0
        ;;
    reboot-rw)
        is_root
        change_cmdline 2
        reboot
        ;;
    *)
        >&2 echo "unknown command, try: status, enable, disable, reboot-rw"
        exit 1
        ;;
esac