Re: Swsusp, resume and kernel versions

[Stefan Seyfried <seife@suse.de>]

Nigel Cunningham wrote:

> If the mistakenly booted kernel isn't suspend enabled, however, you need
> a more generic method of removing the image, such as mkswapping the
> storage device. This is what I was speaking of.

The following code is used in the SUSE bootscripts to do exactly this:

----------------------------------------------------
get_swap_id() {
    local line;
    fdisk -l | while read line; do
        case "$line" in
        /*Linux\ [sS]wap*) echo "${line%% *}"
        esac
    done
}

check_swap_sig () {
    local part="$(get_swap_id)"
    local where what type rest p c
    while read  where what type rest ; do
        test "$type" = "swap" || continue
        c=continue
        for p in $part ; do
            test "$p" = "$where" && c=true
        done
        $c
        case "$(dd if=$where bs=1 count=6 skip=4086 2>/dev/null)" in
        S1SUSP|S2SUSP) mkswap $where
        esac
    done < /etc/fstab
}
---------------------------------------------------------------------

This invalidates the suspend signature if the kernel has not already
done it. It probably does not cover the softwaresuspend2 signature but
that should be trivial to add.

Regards,

  Stefan