Re: [PATCH v1 1/4] scripts/config: import Kconfig manipulation tool from Linux

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 15 Jan 2026, dmukhin@xxxxxxx wrote:
> From: Denis Mukhin <dmukhin@xxxxxxxx> 
> 
> Manipulating Kconfig settings is often required when preparing a custom
> Xen build using an external build system (e.g., a Yocto-based workflow).
> 
> Import the Kconfig manipulation tool from the Linux kernel
> (commit 0f61b1860cc3, Linux v6.19-rc5) to support this use case.
> 
> Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>

Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
>  xen/scripts/config | 236 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 236 insertions(+)
>  create mode 100755 xen/scripts/config
> 
> diff --git a/xen/scripts/config b/xen/scripts/config
> new file mode 100755
> index 000000000000..ea475c07de28
> --- /dev/null
> +++ b/xen/scripts/config
> @@ -0,0 +1,236 @@
> +#!/usr/bin/env bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Manipulate options in a .config file from the command line
> +
> +myname=${0##*/}
> +
> +# If no prefix forced, use the default CONFIG_
> +CONFIG_="${CONFIG_-CONFIG_}"
> +
> +# We use an uncommon delimiter for sed substitutions
> +SED_DELIM=$(echo -en "\001")
> +
> +usage() {
> +     cat >&2 <<EOL
> +Manipulate options in a .config file from the command line.
> +Usage:
> +$myname options command ...
> +commands:
> +     --enable|-e option   Enable option
> +     --disable|-d option  Disable option
> +     --module|-m option   Turn option into a module
> +     --set-str option string
> +                          Set option to "string"
> +     --set-val option value
> +                          Set option to value
> +     --undefine|-u option Undefine option
> +     --state|-s option    Print state of option (n,y,m,undef)
> +
> +     --enable-after|-E beforeopt option
> +                             Enable option directly after other option
> +     --disable-after|-D beforeopt option
> +                             Disable option directly after other option
> +     --module-after|-M beforeopt option
> +                             Turn option into module directly after other 
> option
> +     --refresh            Refresh the config using old settings
> +
> +     commands can be repeated multiple times
> +
> +options:
> +     --file config-file   .config file to change (default .config)
> +     --keep-case|-k       Keep next symbols' case (dont' upper-case it)
> +
> +$myname doesn't check the validity of the .config file. This is done at next
> +make time.
> +
> +By default, $myname will upper-case the given symbol. Use --keep-case to keep
> +the case of all following symbols unchanged.
> +
> +$myname uses 'CONFIG_' as the default symbol prefix. Set the environment
> +variable CONFIG_ to the prefix to use. Eg.: CONFIG_="FOO_" $myname ...
> +EOL
> +     exit 1
> +}
> +
> +checkarg() {
> +     ARG="$1"
> +     if [ "$ARG" = "" ] ; then
> +             usage
> +     fi
> +     case "$ARG" in
> +     ${CONFIG_}*)
> +             ARG="${ARG/${CONFIG_}/}"
> +             ;;
> +     esac
> +     if [ "$MUNGE_CASE" = "yes" ] ; then
> +             ARG="`echo $ARG | tr a-z A-Z`"
> +     fi
> +}
> +
> +txt_append() {
> +     local anchor="$1"
> +     local insert="$2"
> +     local infile="$3"
> +     local tmpfile="$infile.swp"
> +
> +     # sed append cmd: 'a\' + newline + text + newline
> +     cmd="$(printf "a\\%b$insert" "\n")"
> +
> +     sed -e "/$anchor/$cmd" "$infile" >"$tmpfile"
> +     # replace original file with the edited one
> +     mv "$tmpfile" "$infile"
> +}
> +
> +txt_subst() {
> +     local before="$1"
> +     local after="$2"
> +     local infile="$3"
> +     local tmpfile="$infile.swp"
> +
> +     sed -e "s$SED_DELIM$before$SED_DELIM$after$SED_DELIM" "$infile" 
> >"$tmpfile"
> +     # replace original file with the edited one
> +     mv "$tmpfile" "$infile"
> +}
> +
> +txt_delete() {
> +     local text="$1"
> +     local infile="$2"
> +     local tmpfile="$infile.swp"
> +
> +     sed -e "/$text/d" "$infile" >"$tmpfile"
> +     # replace original file with the edited one
> +     mv "$tmpfile" "$infile"
> +}
> +
> +set_var() {
> +     local name=$1 new=$2 before=$3
> +
> +     name_re="^($name=|# $name is not set)"
> +     before_re="^($before=|# $before is not set)"
> +     if test -n "$before" && grep -Eq "$before_re" "$FN"; then
> +             txt_append "^$before=" "$new" "$FN"
> +             txt_append "^# $before is not set" "$new" "$FN"
> +     elif grep -Eq "$name_re" "$FN"; then
> +             txt_subst "^$name=.*" "$new" "$FN"
> +             txt_subst "^# $name is not set" "$new" "$FN"
> +     else
> +             echo "$new" >>"$FN"
> +     fi
> +}
> +
> +undef_var() {
> +     local name=$1
> +
> +     txt_delete "^$name=" "$FN"
> +     txt_delete "^# $name is not set" "$FN"
> +}
> +
> +FN=.config
> +CMDS=()
> +while [[ $# -gt 0 ]]; do
> +     if [ "$1" = "--file" ]; then
> +             if [ "$2" = "" ]; then
> +                     usage
> +             fi
> +             FN="$2"
> +             shift 2
> +     else
> +             CMDS+=("$1")
> +             shift
> +     fi
> +done
> +
> +set -- "${CMDS[@]}"
> +if [ "$1" = "" ] ; then
> +     usage
> +fi
> +
> +MUNGE_CASE=yes
> +while [ "$1" != "" ] ; do
> +     CMD="$1"
> +     shift
> +     case "$CMD" in
> +     --keep-case|-k)
> +             MUNGE_CASE=no
> +             continue
> +             ;;
> +     --refresh)
> +             ;;
> +     --*-after|-E|-D|-M)
> +             checkarg "$1"
> +             A=$ARG
> +             checkarg "$2"
> +             B=$ARG
> +             shift 2
> +             ;;
> +     -*)
> +             checkarg "$1"
> +             shift
> +             ;;
> +     esac
> +     case "$CMD" in
> +     --enable|-e)
> +             set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=y"
> +             ;;
> +
> +     --disable|-d)
> +             set_var "${CONFIG_}$ARG" "# ${CONFIG_}$ARG is not set"
> +             ;;
> +
> +     --module|-m)
> +             set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=m"
> +             ;;
> +
> +     --set-str)
> +             # sed swallows one level of escaping, so we need double-escaping
> +             set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=\"${1//\"/\\\\\"}\""
> +             shift
> +             ;;
> +
> +     --set-val)
> +             set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=$1"
> +             shift
> +             ;;
> +     --undefine|-u)
> +             undef_var "${CONFIG_}$ARG"
> +             ;;
> +
> +     --state|-s)
> +             if grep -q "# ${CONFIG_}$ARG is not set" $FN ; then
> +                     echo n
> +             else
> +                     V="$(grep "^${CONFIG_}$ARG=" $FN)"
> +                     if [ $? != 0 ] ; then
> +                             echo undef
> +                     else
> +                             V="${V/#${CONFIG_}$ARG=/}"
> +                             V="${V/#\"/}"
> +                             V="${V/%\"/}"
> +                             V="${V//\\\"/\"}"
> +                             echo "${V}"
> +                     fi
> +             fi
> +             ;;
> +
> +     --enable-after|-E)
> +             set_var "${CONFIG_}$B" "${CONFIG_}$B=y" "${CONFIG_}$A"
> +             ;;
> +
> +     --disable-after|-D)
> +             set_var "${CONFIG_}$B" "# ${CONFIG_}$B is not set" 
> "${CONFIG_}$A"
> +             ;;
> +
> +     --module-after|-M)
> +             set_var "${CONFIG_}$B" "${CONFIG_}$B=m" "${CONFIG_}$A"
> +             ;;
> +
> +     --refresh)
> +             yes "" | make oldconfig KCONFIG_CONFIG=$FN
> +             ;;
> +
> +     *)
> +             echo "bad command: $CMD" >&2
> +             usage
> +             ;;
> +     esac
> +done
> -- 
> 2.52.0
>