commit 42e04f36f5f8eea0017915bb35e56ee285b394d7

Merge: 7c6296db 940fede7

Author: Johannes Meixner <jsmeix@suse.com>

Date:   Tue Jan 31 13:13:56 2023 +0100

    Merge pull request #2915 from rear/jsmeix-serial-devs-fail-safe

    In lib/serial-functions.sh make the

    get_serial_console_devices() function

    fail-safe if no serial device node exists, see

    https://github.com/rear/rear/issues/2914

diff --git a/usr/share/rear/lib/serial-functions.sh b/usr/share/rear/lib/serial-functions.sh

index aac5dc88..3d421b52 100644

--- a/usr/share/rear/lib/serial-functions.sh

+++ b/usr/share/rear/lib/serial-functions.sh

@@ -1,13 +1,24 @@

 # Get available serial devices:

 function get_serial_console_devices () {

-    test "$SERIAL_CONSOLE_DEVICES" && echo $SERIAL_CONSOLE_DEVICES || ls /dev/ttyS[0-9]* /dev/hvsi[0-9]* | sort

+    # Via SERIAL_CONSOLE_DEVICES the user specifies which ones to use (and no others):

+    if test "$SERIAL_CONSOLE_DEVICES" ; then

+        echo $SERIAL_CONSOLE_DEVICES

+        return 0

+    fi

+    # Test if there is /dev/ttyS[0-9]* or /dev/hvsi[0-9]*

+    # because when there is neither /dev/ttyS[0-9]* nor /dev/hvsi[0-9]*

+    # the ls command below would become plain 'ls' because of 'nullglob'

+    # cf. "Beware of the emptiness" in https://github.com/rear/rear/wiki/Coding-Style

+    # see https://github.com/rear/rear/issues/2914#issuecomment-1396659184

+    # and return 0 because it is no error when no serial device node exists

+    test "$( echo -n /dev/ttyS[0-9]* /dev/hvsi[0-9]* )" || return 0

     # Use plain 'sort' which results /dev/ttyS0 /dev/ttyS1 /dev/ttyS10 ... /dev/ttyS19 /dev/ttyS2 /dev/ttyS20 ...

     # to get at least /dev/ttyS0 and /dev/ttyS1 before the other /dev/ttyS* devices because

     # we cannot use "sort -V" which would result /dev/ttyS0 /dev/ttyS1 ... /dev/ttyS9 /dev/ttyS10 ...

     # because in older Linux distributions 'sort' does not support '-V' e.g. SLES10 with GNU coreutils 5.93

     # (SLES11 with GNU coreutils 8.12 supports 'sort -V') but if 'sort' fails there is no output at all

-    # cf. "Maintain backward compatibility" at https://github.com/rear/rear/wiki/Coding-Style

+    # cf. "Maintain backward compatibility" in https://github.com/rear/rear/wiki/Coding-Style

     # Furthermore 'sort' results that /dev/hvsi* devices appear before /dev/ttyS* devices

     # so the create_grub2_serial_entry function in lib/bootloader-functions.sh

     # which uses by default the first one and skips the rest will result that

@@ -16,7 +27,8 @@ function get_serial_console_devices () {

     # that have the HVSI driver loaded (a console driver for IBM's p5 servers)

     # cf. https://lwn.net/Articles/98442/

     # and it seems right that when special console drivers are loaded

-    # then their devices should be preferred by default.

+    # then their devices should be preferred by default:

+    ls /dev/ttyS[0-9]* /dev/hvsi[0-9]* | sort

 }

 # Get the serial device speed for those device nodes that belong to actual serial devices.

commit 07da02143b5597b202e66c187e53103561018255

Merge: 91942f63 75a23e79

Author: Johannes Meixner <jsmeix@suse.com>

Date:   Fri Oct 20 14:45:23 2023 +0200

    Merge pull request #2961 from rear/jsmeix-copy-serial-console

    For the automated serial console setup for the recovery system

    use only the 'console=...' kernel arguments from the original system

    which fixes https://github.com/rear/rear/issues/2843

    and it means that no longer all "real serial devices" get

    auto-enabled as serial consoles in the recovery system, see

    https://github.com/rear/rear/pull/2749#issuecomment-1196650631

    That new default behaviour is described in default.conf.

    In particular prep/GNU/Linux/200_include_serial_console.sh

    and lib/serial-functions.sh were overhauled which results

    that rescue/GNU/Linux/400_use_serial_console.sh is obsolete.

    Cherry-picked-by: Lukáš Zaoral <lzaoral@redhat.com>

diff --git a/usr/share/rear/conf/default.conf b/usr/share/rear/conf/default.conf

index ec1691b6..76355fb8 100644

--- a/usr/share/rear/conf/default.conf

+++ b/usr/share/rear/conf/default.conf

@@ -3320,39 +3320,90 @@ SIMPLIFY_TEAMING=no

 SIMPLIFY_TEAMING=no

 # Serial console support for the ReaR rescue/recovery system:

-# By default serial consoles get enabled if serial devices are found and

-# then matching kernel command line parameters like 'console=ttyS0,9600 console=ttyS1,9600'

-# are set when booting the rescue/recovery system (see KERNEL_CMDLINE above).

 # IA64 platforms require it and people need it when no VGA console is available.

-# Specify 'yes' or 'no' or leave it empty to use ReaR's automatism:

+# By default there is serial console support in the ReaR recovery system

+# when 'getty' or 'agetty' and 'stty' can be found,

+# otherwise USE_SERIAL_CONSOLE is automatically set to 'no'.

+# When 'getty' or 'agetty' and 'stty' can be found

+# and there is a 'console=...' option in /proc/cmdline,

+# then USE_SERIAL_CONSOLE is automatically set to 'yes'.

+# With USE_SERIAL_CONSOLE="no" no serial console gets set up,

+# neither for the recovery system kernel nor for the recovery system bootloader.

+# With USE_SERIAL_CONSOLE="yes" plus appropriate SERIAL_CONSOLE_DEVICE... settings

+# serial consoles can be specified for the recovery system kernel and bootloader

+# for example when there is no 'console=...' option in /proc/cmdline

+# or when serial consoles for the recovery system kernel and bootloader

+# should differ from what 'console=...' options in /proc/cmdline tell.

+# By default (when empty) the automatism further described below is used:

 USE_SERIAL_CONSOLE=

-# If you do not want to use all serial devices found as console you can specify the ones to use

-# e.g. SERIAL_CONSOLE_DEVICES="/dev/ttyS0 /dev/ttyS1" provided USE_SERIAL_CONSOLE is turned on.

-# By default (when empty) all serial devices found are used:

+#

+# Devices to be used in general for serial console setup

+# unless explicitly specified via SERIAL_CONSOLE_DEVICES_KERNEL

+# or SERIAL_CONSOLE_DEVICE_SYSLINUX or SERIAL_CONSOLE_DEVICE_GRUB:

+# E.g. SERIAL_CONSOLE_DEVICES="/dev/ttyS0 /dev/ttyS1"

 SERIAL_CONSOLE_DEVICES=

-# Serial consoles for the kernel of the recovery system:

+#

+# Serial consoles for the kernel of the recovery system

+# provided USE_SERIAL_CONSOLE is not 'no':

 # SERIAL_CONSOLE_DEVICES_KERNEL can be device nodes like "/dev/ttyS0 /dev/ttyS1"

 # or 'console=...' kernel parameters like "console=ttyS1,9600 console=tty0" or both like

 # SERIAL_CONSOLE_DEVICES_KERNEL="/dev/ttyS0 console=ttyS1,9600 console=tty0"

-# provided USE_SERIAL_CONSOLE is turned on.

-# By default (when empty) the SERIAL_CONSOLE_DEVICES are used for the kernel:

+# When SERIAL_CONSOLE_DEVICES_KERNEL is empty but SERIAL_CONSOLE_DEVICES is specified

+# then the specified SERIAL_CONSOLE_DEVICES are used for the kernel.

+# By default (when SERIAL_CONSOLE_DEVICES_KERNEL and SERIAL_CONSOLE_DEVICES are empty)

+# serial consoles get enabled for the recovery system kernel via COPY_KERNEL_PARAMETERS

+# for all 'console=...' options that are found in /proc/cmdline.

 SERIAL_CONSOLE_DEVICES_KERNEL=

-# Serial console for SYSLINUX/EXTLINUX when it is used as bootloader for the recovery system:

+#

+# Serial console for SYSLINUX/EXTLINUX when it is used as bootloader for the recovery system

+# provided USE_SERIAL_CONSOLE is 'yes' (automatically with 'console=...' in /proc/cmdline):

 # SYSLINUX supports only one serial device (because the last SYSLINUX 'serial' directive wins).

 # The right /dev/ttyS* can be specified like SERIAL_CONSOLE_DEVICE_SYSLINUX="/dev/ttyS0"

 # or a whole SYSLINUX 'serial' directive can be specified e.g. for /dev/ttyS1 like

 # SERIAL_CONSOLE_DEVICE_SYSLINUX="serial 1 9600"

-# provided USE_SERIAL_CONSOLE is turned on.

-# By default (when empty) the first one of SERIAL_CONSOLE_DEVICES is used for SYSLINUX:

+# When SERIAL_CONSOLE_DEVICE_SYSLINUX is empty but SERIAL_CONSOLE_DEVICES is specified

+# then the first one of SERIAL_CONSOLE_DEVICES is used for SYSLINUX.

+# By default (when SERIAL_CONSOLE_DEVICE_SYSLINUX and SERIAL_CONSOLE_DEVICES are empty)

+# the devices of the 'console=...' options in /proc/cmdline

+# that exist as /dev/ttyS* or /dev/hvsi* character device nodes are used

+# (which excludes /dev/tty0 when there is 'console=tty0' in /proc/cmdline).

 SERIAL_CONSOLE_DEVICE_SYSLINUX=

-# Serial console for GRUB when it is used as bootloader for the recovery system:

+#

+# Serial console for GRUB when it is used as bootloader for the recovery system

+# provided USE_SERIAL_CONSOLE is 'yes' (automatically with 'console=...' in /proc/cmdline):

 # GRUB supports only one serial device (because the last GRUB 'serial' command wins).

 # The right /dev/ttyS* can be specified like SERIAL_CONSOLE_DEVICE_GRUB="/dev/ttyS0"

 # or a whole GRUB 'serial' command can be specified e.g. for /dev/ttyS1 like

 # SERIAL_CONSOLE_DEVICE_GRUB="serial --unit=1 --speed=9600"

-# provided USE_SERIAL_CONSOLE is turned on.

-# By default (when empty) the first one of SERIAL_CONSOLE_DEVICES is used for GRUB:

+# When SERIAL_CONSOLE_DEVICE_GRUB is empty but SERIAL_CONSOLE_DEVICES is specified

+# then the first one of SERIAL_CONSOLE_DEVICES is used for GRUB.

+# By default (when SERIAL_CONSOLE_DEVICE_GRUB and SERIAL_CONSOLE_DEVICES are empty)

+# the devices of the 'console=...' options in /proc/cmdline

+# that exist as /dev/ttyS* or /dev/hvsi* character device nodes are used

+# (which excludes /dev/tty0 when there is 'console=tty0' in /proc/cmdline).

 SERIAL_CONSOLE_DEVICE_GRUB=

+#

+# Examples

+# (provided USE_SERIAL_CONSOLE is not 'no'

+# and 'getty' or 'agetty' and 'stty' can be found):

+#

+# Default behaviour

+# when there is no 'console=...' option in /proc/cmdline

+# then no serial console is set up for the recovery system.

+#

+# Default behaviour when there are for example

+# 'console=ttyS0,9600' and 'console=tty0' in /proc/cmdline

+# then 'console=ttyS0,9600' and 'console=tty0'

+# are used for the recovery system kernel

+# and only /dev/ttyS0 is used as serial console

+# for the recovery system bootloader (SYSLINUX or GRUB).

+#

+# On a headless machine without VGA card but with serial device /dev/ttyS0

+# the kernel would choose /dev/ttyS0 as its console automatically

+# so no 'console=...' kernel option needs to be used and then the automatism described above

+# would not set up a console for the recovery system (in particular not for the bootloader).

+# In this case USE_SERIAL_CONSOLE="yes" and appropriate SERIAL_CONSOLE_DEVICE... settings

+# are needed to manually specify the right console setup for the recovery system.

 # Say "y", "Yes", etc, to enable or "n", "No" etc. to disable the DHCP client protocol or leave empty to autodetect.

 # When enabled, lets the rescue/recovery system run dhclient to get an IP address

 # instead of using the same IP address as the original system:

diff --git a/usr/share/rear/lib/serial-functions.sh b/usr/share/rear/lib/serial-functions.sh

index 3d421b52..a586d357 100644

--- a/usr/share/rear/lib/serial-functions.sh

+++ b/usr/share/rear/lib/serial-functions.sh

@@ -6,29 +6,34 @@ function get_serial_console_devices () {

         echo $SERIAL_CONSOLE_DEVICES

         return 0

     fi

-    # Test if there is /dev/ttyS[0-9]* or /dev/hvsi[0-9]*

-    # because when there is neither /dev/ttyS[0-9]* nor /dev/hvsi[0-9]*

-    # the ls command below would become plain 'ls' because of 'nullglob'

-    # cf. "Beware of the emptiness" in https://github.com/rear/rear/wiki/Coding-Style

-    # see https://github.com/rear/rear/issues/2914#issuecomment-1396659184

-    # and return 0 because it is no error when no serial device node exists

-    test "$( echo -n /dev/ttyS[0-9]* /dev/hvsi[0-9]* )" || return 0

-    # Use plain 'sort' which results /dev/ttyS0 /dev/ttyS1 /dev/ttyS10 ... /dev/ttyS19 /dev/ttyS2 /dev/ttyS20 ...

-    # to get at least /dev/ttyS0 and /dev/ttyS1 before the other /dev/ttyS* devices because

-    # we cannot use "sort -V" which would result /dev/ttyS0 /dev/ttyS1 ... /dev/ttyS9 /dev/ttyS10 ...

-    # because in older Linux distributions 'sort' does not support '-V' e.g. SLES10 with GNU coreutils 5.93

-    # (SLES11 with GNU coreutils 8.12 supports 'sort -V') but if 'sort' fails there is no output at all

-    # cf. "Maintain backward compatibility" in https://github.com/rear/rear/wiki/Coding-Style

-    # Furthermore 'sort' results that /dev/hvsi* devices appear before /dev/ttyS* devices

-    # so the create_grub2_serial_entry function in lib/bootloader-functions.sh

-    # which uses by default the first one and skips the rest will result that

-    # the first /dev/hvsi* device becomes used for the GRUB serial console by default

-    # which looks right because /dev/hvsi* devices should exist only on systems

-    # that have the HVSI driver loaded (a console driver for IBM's p5 servers)

-    # cf. https://lwn.net/Articles/98442/

-    # and it seems right that when special console drivers are loaded

-    # then their devices should be preferred by default:

-    ls /dev/ttyS[0-9]* /dev/hvsi[0-9]* | sort

+    # Scan the kernel command line of the currently running original system

+    # for 'console=<device>[,<options>]' settings e.g. 'console=ttyS1,9600n8 ... console=ttyS3 ... console=tty0'

+    # and extract the specified serial device nodes e.g. ttyS1 -> /dev/ttyS1 ... ttyS3 -> /dev/ttyS3

+    local kernel_option console_option_value console_option_device

+    for kernel_option in $( cat /proc/cmdline ) ; do

+        # Continue with next kernel option when the option name (part before leftmost "=") is not 'console':

+        test "${kernel_option%%=*}" = "console" || continue

+        # Get the console option value (part after leftmost "=") e.g. 'ttyS1,9600n8' 'ttyS3' 'tty0'

+        console_option_value="${kernel_option#*=}"

+        # Get the console option device (part before leftmost optional ',' separator) e.g. 'ttyS1' 'ttyS3' 'tty0'

+        console_option_device="${console_option_value%%,*}"

+        # Continue with next kernel option when the current console option device is no serial device (exclude 'tty0').

+        # The special /dev/hvsi* devices should exist only on systems that have the HVSI driver loaded

+        # (a console driver for IBM's p5 servers) cf. https://lwn.net/Articles/98442/

+        [[ $console_option_device == ttyS* ]] || [[ $console_option_device == hvsi* ]] || continue

+        # Test that the matching serial device node e.g. ttyS1 -> /dev/ttyS1 and ttyS3 -> /dev/ttyS3' exists

+        # to avoid that this automated serial console setup may not work in the ReaR recovery system

+        # when serial device nodes get specified for the recovery system that do not exist

+        # in the currently running original system because the default assumption is

+        # that the replacement system has same hardware as the original system,

+        # cf. https://github.com/rear/rear/pull/2749#issuecomment-1196650631

+        # (if needed the user can specify what he wants via SERIAL_CONSOLE_DEVICES, see above):

+        if ! test -c "/dev/$console_option_device" ; then

+            LogPrintError "Found '$kernel_option' in /proc/cmdline but '/dev/$console_option_device' is no character device"

+            continue

+        fi

+        echo /dev/$console_option_device

+    done

 }

 # Get the serial device speed for those device nodes that belong to actual serial devices.

@@ -39,64 +44,15 @@ function get_serial_device_speed () {

     # Run it in a subshell so that 'set -o pipefail' does not affect the current shell and

     # it can run in a subshell because the caller of this function only needs its stdout

     # cf. the function get_root_disk_UUID in lib/bootloader-functions.sh

-    # so when stty fails the get_serial_device_speed return code is the stty exit code and not the awk exit code

-    # therefore one can call get_serial_device_speed with error checking for example like

+    # so when stty fails the get_serial_device_speed return code is the stty exit code and not the awk exit code.

+    # Therefore one can call get_serial_device_speed with error checking for example like

     # speed=$( get_serial_device_speed $serial_device ) && COMMAND_WITH_speed || COMMAND_WITHOUT_speed

-    # because the return code of variable=$( PIPE ) is the return code of the pipe,

-    # cf. how get_serial_device_speed is called in cmdline_add_console below.

+    # because the return code of variable=$( PIPE ) is the return code of the pipe

+    # cf. how get_serial_device_speed is called in lib/bootloader-functions.sh

+    # and output/USB/Linux-i386/300_create_extlinux.sh

     # Suppress stty stderr output because for most /dev/ttyS* device nodes the result is

     #   stty: /dev/ttyS...: Input/output error

     # when the device node does not belong to an actual serial device (i.e. to real serial hardware)

     # so get_serial_device_speed is also used to get those device nodes that belong to real serial devices:

     ( set -o pipefail ; stty -F $devnode 2>/dev/null | awk '/^speed / { print $2 }' )

 }

-

-# Add serial console to kernel cmdline:

-function cmdline_add_console {

-    # Nothing to do when using serial console is not wanted:

-    is_true "$USE_SERIAL_CONSOLE" || return 0

-

-    # Strip existing 'console=...' kernel cmd parameters:

-    local param cmdline=""

-    for param in $KERNEL_CMDLINE ; do

-        case "$param" in

-            (console=*) ;;

-            (*) cmdline+=" $param";;

-        esac

-    done

-

-    # Add serial console config to kernel cmd line:

-    local devnode speed=""

-    if test "$SERIAL_CONSOLE_DEVICES_KERNEL" ; then

-        # When the user has specified SERIAL_CONSOLE_DEVICES_KERNEL use only that (no automatisms):

-        for devnode in $SERIAL_CONSOLE_DEVICES_KERNEL ; do

-            # devnode can be a character device node like "/dev/ttyS0" or "/dev/lp0" or "/dev/ttyUSB0"

-            # cf. https://www.kernel.org/doc/html/latest/admin-guide/serial-console.html

-            # or devnode can be a 'console=...' kernel cmd parameter like "console=ttyS1,9600"

-            if test -c "$devnode" ; then

-                if speed=$( get_serial_device_speed $devnode ) ; then

-                    cmdline+=" console=${devnode##/dev/},$speed"

-                else

-                    cmdline+=" console=${devnode##/dev/}"

-                fi

-            else

-                # When devnode is a 'console=...' kernel cmd parameter use it as specified:

-                cmdline+=" $devnode"

-            fi

-        done

-    else

-        local real_consoles=""

-        for devnode in $( get_serial_console_devices ) ; do

-            # Only add for those device nodes that belong to actual serial devices:

-            speed=$( get_serial_device_speed $devnode ) && real_consoles+=" console=${devnode##/dev/},$speed"

-        done

-        cmdline+=" $real_consoles"

-

-        # Add fallback console if no real serial device was found:

-        test "$real_consoles" || cmdline+=" console=tty0"

-    fi

-

-    # Have a trailing space to be on the safe side

-    # so that more kernel cmd parameters could be "just appended" by other scripts:

-    echo "$cmdline "

-}

diff --git a/usr/share/rear/prep/GNU/Linux/200_include_serial_console.sh b/usr/share/rear/prep/GNU/Linux/200_include_serial_console.sh

index 214af3c4..14ec113e 100644

--- a/usr/share/rear/prep/GNU/Linux/200_include_serial_console.sh

+++ b/usr/share/rear/prep/GNU/Linux/200_include_serial_console.sh

@@ -1,31 +1,115 @@

-# If possible auto-enable serial console when not specified:

-if [[ -z "$USE_SERIAL_CONSOLE" ]] ; then

-    local devnode speed=""

-    for devnode in $( get_serial_console_devices ) ; do

-        # Enable serial console when there is at least one real serial device:

-        if speed=$( get_serial_device_speed $devnode ) ; then

-            USE_SERIAL_CONSOLE="yes"

-            break

-        fi

-    done

-fi

+# This script prep/GNU/Linux/200_include_serial_console.sh

+# is the first ...console... script that is run for "rear mkrescue/mkbackup".

+#

+# When USE_SERIAL_CONSOLE is empty then this script decides

+# if USE_SERIAL_CONSOLE is kept empty

+# or (provided there is sufficient reason)

+# it sets USE_SERIAL_CONSOLE to 'no' or 'yes'.

+# It sets USE_SERIAL_CONSOLE to 'no'

+# when serial consoles cannot work in the recovery system.

+# It sets USE_SERIAL_CONSOLE to 'yes'

+# when a serial console will be set up for the recovery system kernel.

+# Only when a serial console will be actually set up for the recovery system kernel,

+# then it makes sense to also set up a serial console for the recovery system bootloader.

+# So serial console setup for the recovery system bootloader is only done if USE_SERIAL_CONSOLE="yes"

+# because an empty USE_SERIAL_CONSOLE must not result serial console setup for the recovery system bootloader

+# (without actual serial console setup for the recovery system kernel).

-# Always include getty or agetty as we don't know in advance whether they are needed

+# Always try to include getty or agetty as we do not know in advance whether they are needed

 # (the user may boot the recovery system with manually specified kernel options

 # to get serial console support in his recovery system).

-# For serial support we need to include the agetty binary,

-# but Debian distro's use getty instead of agetty:

-local getty_binary=""

+# For serial console support we need to include 'getty' or 'agetty'.

+# Debian distributions (in particular Ubuntu) use 'getty'.

+# Fedora, RHEL, SLES,... use 'agetty'.

 if has_binary getty ; then

-    # Debian, Ubuntu,...

-    getty_binary="getty"

+    PROGS+=( getty )

 elif has_binary agetty ; then

-    # Fedora, RHEL, SLES,...

-    getty_binary="agetty"

+    PROGS+=( agetty )

+else

+    is_true "$USE_SERIAL_CONSOLE" && Error "Failed to find 'getty' or 'agetty' (USE_SERIAL_CONSOLE is 'true')"

+    LogPrintError "No serial console support (failed to find 'getty' or 'agetty')"

+    USE_SERIAL_CONSOLE="no"

+fi

+

+# Also try to include 'stty' which is (currently) only needed for serial console support

+# in skel/default/etc/scripts/system-setup.d/45-serial-console.sh

+# and lib/serial-functions.sh

+if has_binary stty ; then

+    PROGS+=( stty )

 else

-    # The user must have the programs in REQUIRED_PROGS installed on his system:

-    Error "Failed to find 'getty' or 'agetty' for serial console"

+    is_true "$USE_SERIAL_CONSOLE" && Error "Failed to find 'stty' (USE_SERIAL_CONSOLE is 'true')"

+    LogPrintError "No serial console support (failed to find 'stty')"

+    USE_SERIAL_CONSOLE="no"

 fi

-REQUIRED_PROGS+=( "$getty_binary" stty )

+# Auto-enable serial console support for the recovery system

+# provided console support is not impossible because there is no getty or agetty and stty

+# and unless the user specified to not have serial console support:

+is_false "$USE_SERIAL_CONSOLE" && return 0

+

+# When the user has specified SERIAL_CONSOLE_DEVICES_KERNEL use only that,

+# otherwise use SERIAL_CONSOLE_DEVICES if the user has specified it:

+local serial_console_devices=""

+test "$SERIAL_CONSOLE_DEVICES" && serial_console_devices="$SERIAL_CONSOLE_DEVICES"

+test "$SERIAL_CONSOLE_DEVICES_KERNEL" && serial_console_devices="$SERIAL_CONSOLE_DEVICES_KERNEL"

+if test "$serial_console_devices" ; then

+    local serial_console speed="" cmdline_add_console=""

+    for serial_console in $serial_console_devices ; do

+        # serial_console can be a character device node like "/dev/ttyS0" or "/dev/lp0" or "/dev/ttyUSB0"

+        # cf. https://www.kernel.org/doc/html/latest/admin-guide/serial-console.html

+        # or serial_console can be a 'console=...' kernel cmd parameter like "console=ttyS1,9600"

+        if test -c "$serial_console" ; then

+            if speed=$( get_serial_device_speed $serial_console ) ; then

+                cmdline_add_console+=" console=${serial_console##/dev/},$speed"

+            else

+                cmdline_add_console+=" console=${serial_console##/dev/}"

+            fi

+        else

+            # When serial_console is not a character device

+            # it should be a 'console=...' kernel cmd parameter

+            # that is used as specified ("final power to the user"):

+            cmdline_add_console+=" $serial_console"

+        fi

+    done

+    if test "$cmdline_add_console" ; then

+        KERNEL_CMDLINE+="$cmdline_add_console"

+        DebugPrint "Appended '$cmdline_add_console' to KERNEL_CMDLINE"

+        USE_SERIAL_CONSOLE="yes"

+        # No further automatisms when a 'console=...' kernel cmd parameter was set

+        # via SERIAL_CONSOLE_DEVICES_KERNEL or SERIAL_CONSOLE_DEVICES:

+        return

+    fi

+    LogPrintError "SERIAL_CONSOLE_DEVICES_KERNEL or SERIAL_CONSOLE_DEVICES specified but none is a character device"

+fi

+

+# Auto-enable serial console support for the recovery system kernel:

+# The below auto-enable serial console support for the recovery system kernel

+# does not auto-enable serial console support for the recovery system bootloader.

+# Currently auto-enable serial console support for the recovery system bootloader

+# happens for the first real serial device from get_serial_console_devices()

+# in lib/bootloader-functions.sh in make_syslinux_config() and create_grub2_cfg() 

+# and in output/USB/Linux-i386/300_create_extlinux.sh

+# The auto-enable serial console support for the recovery system bootloader should be

+# auto-aligned with the auto-enable serial console support for the recovery system kernel.

+# Things are auto-aligned when the first 'console=...' device in /proc/cmdline

+# is also the first real serial device from get_serial_console_devices().

+# When current auto-alignment does not result what the user needs, what is needed can be specified

+# via SERIAL_CONSOLE_DEVICES_KERNEL and SERIAL_CONSOLE_DEVICE_SYSLINUX or SERIAL_CONSOLE_DEVICE_GRUB.

+

+# Scan the kernel command line of the currently running original system

+# and auto-enable serial console for the recovery system kernel

+# only if there is at least one 'console=...' option:

+local kernel_option

+for kernel_option in $( cat /proc/cmdline ) ; do

+    # Get the kernel option name (part before leftmost "="):

+    if test "${kernel_option%%=*}" = "console" ; then

+        USE_SERIAL_CONSOLE="yes"

+        # Get all 'console=...' kernel command line options

+        # copied from the currently running original system

+        # via rescue/GNU/Linux/290_kernel_cmdline.sh that runs later:

+        COPY_KERNEL_PARAMETERS+=( console )

+        return

+    fi

+done

+DebugPrint "No 'console=...' setting for recovery system kernel (none in /proc/cmdline)"

diff --git a/usr/share/rear/rescue/GNU/Linux/400_use_serial_console.sh b/usr/share/rear/rescue/GNU/Linux/400_use_serial_console.sh

deleted file mode 100644

index fc935844..00000000

--- a/usr/share/rear/rescue/GNU/Linux/400_use_serial_console.sh

+++ /dev/null

@@ -1,6 +0,0 @@

-

-# Nothing to do when using serial console is not wanted:

-is_true "$USE_SERIAL_CONSOLE" || return 0

-

-KERNEL_CMDLINE=$( cmdline_add_console )

-Log "Modified kernel commandline to: '$KERNEL_CMDLINE'"