How to Exclude Specific Lines from /etc/inittab in Yocto sysvinit-inittab Recipe?

Question

I am working with the Yocto build system and have encountered an issue with a recipe that manages /etc/inittab. Specifically, I am using the Karo Q93 board and the Karo layers in my build. One of the supplier's (Karo) appended recipes, sysvinit-inittab, adds some lines to /etc/inittab as shown below:

do_install () {
    install -d ${D}${sysconfdir}
    install -m 0644 ${WORKDIR}/inittab ${D}${sysconfdir}/inittab

    i=0
    cons="${SERIAL_CONSOLES}"
    for c in ${cons}; do
        if [ $i = 0 ]; then
            grep -q '# Serial consoles on the standard serial ports' ${D}${sysconfdir}/inittab && break
            cat <<EOF >> ${D}${sysconfdir}/inittab
#
# Serial consoles on the standard serial ports
EOF
        fi
        j=`echo ${c} | sed 's/;/ /g'`
        l=`echo ${c} | sed 's/tty//;s/^.*;//;s/;.*//'`
        echo "s$i:123:respawn:${base_sbindir}/getty -L ${j} linux" >> ${D}${sysconfdir}/inittab
        i=`expr $i + 1`
    done

    if [ "${USE_VT}" = "1" ]; then
        cat <<EOF >> ${D}${sysconfdir}/inittab

In my application, I use the serial port (/dev/ttyLP2) for some communication, but the recipe above adds the line s2:123:respawn:/sbin/getty -L 115200 ttyLP2 linux to /etc/inittab, which causes a getty process to attach to /dev/ttyLP2. I want to remove or skip adding that line into /etc/inittab during the build process.

I attempted to append to the same recipe from my custom layer with a file that comments out the problematic line, but it didn't work as expected. This approach ended up corrupting the /etc/inittab file, resulting in the removal of other necessary lines. Below is the content of my custom append file sysvinit-inittab_%.bbappend:

FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
SRC_URI += "file://inittab"

And the content of the inittab file is:

#s2:123:respawn:/sbin/getty -L 115200 ttyLP2 linux

Unfortunately, this solution didn't resolve the issue and caused additional problems with the /etc/inittab file. Could anyone suggest an efficient way to solve this problem without affecting other configurations in /etc/inittab?

Answer 1

I've solved it by updating the custom append file sysvinit-inittab_%.bbappend to comment out the specific line using sed in do_install:

do_install:append() {
    # Comment out the line
    sed -i 's|^s2:123:respawn:/sbin/getty -L 115200 ttyLP2 linux|#s2:123:respawn:/sbin/getty -L 115200 ttyLP2 linux|' ${D}${sysconfdir}/inittab
}

Additionally, I made sure that my custom layer is prioritized in the conf/layer.conf to ensure that my changes take effect.