kconfig-tweak

name	kconfig-tweak
description	Modify Linux kernel or NuttX .config files from command line without interactive menuconfig. Use when needing to enable/disable config options, set values, query option states, or batch-modify kernel configurations in scripts or CI/CD pipelines.

kconfig-tweak

Command-line tool for modifying .config files without launching interactive menuconfig.

Quick Reference

# Enable/disable options
kconfig-tweak --enable DEBUG_INFO
kconfig-tweak --disable MODULES
kconfig-tweak -e SMP -d PREEMPT    # Multiple in one command

# Set values
kconfig-tweak --set-val LOG_BUF_SHIFT 17
kconfig-tweak --set-str LOCALVERSION "-custom"

# Query state
kconfig-tweak --state DEBUG_INFO   # Returns: y, n, m, or undef

# Specify config file
kconfig-tweak --file boards/myboard/.config --enable USB

# Module support
kconfig-tweak --module DRM         # Set to m (module)

Commands

Command	Short	Description
--enable OPTION	-e	Set option to y
--disable OPTION	-d	Set option to n
--module OPTION	-m	Set option to m (module)
--set-val OPTION VALUE	-	Set integer/hex value
--set-str OPTION STRING	-	Set string value (quoted)
--undefine OPTION	-u	Remove option definition
--state OPTION	-s	Query current state

Position Control

Insert options after a specific option (useful for maintaining config order):

kconfig-tweak --enable-after USB USB_STORAGE    # -E
kconfig-tweak --disable-after NET BRIDGE        # -D
kconfig-tweak --module-after DRM DRM_I915       # -M

Options

Option	Description
--file FILE	Target config file (default: .config)
--keep-case / -k	Preserve symbol case (default: auto-uppercase)

Environment Variables

• CONFIG_ - Symbol prefix (default: "CONFIG_")

Common Patterns

Batch Configuration

# Enable multiple debug options
kconfig-tweak -e DEBUG_INFO -e DEBUG_FS -e KALLSYMS

# Configure network stack
kconfig-tweak --file .config \
  -e NET -e INET -e IPV6 \
  --set-val TCP_CONG_CUBIC y

CI/CD Integration

# Start from defconfig, then customize
make defconfig
kconfig-tweak -e DEBUG_INFO -d MODULES
make olddefconfig  # Resolve dependencies

Query Before Modify

# Check current state
STATE=$(kconfig-tweak -s PREEMPT)
if [ "$STATE" = "y" ]; then
  kconfig-tweak -d PREEMPT
fi

Notes

• kconfig-tweak does NOT validate dependencies; run make olddefconfig after modifications
• Symbol names auto-uppercase unless --keep-case is used
• Changes are immediate; no confirmation prompt