From 2e90372692f5243caf2d196cd714d708f5fba5e3 Mon Sep 17 00:00:00 2001
From: desertwitch <24509509+desertwitch@users.noreply.github.com>
Date: Wed, 19 Nov 2025 10:25:37 +0100
Subject: [PATCH] chore: update buildscript and documentation

Signed-off-by: desertwitch <24509509+desertwitch@users.noreply.github.com>
---
 board/shredos/embed/README |   8 +-
 build_all_shredos.sh       | 490 ++++++++++++++++++++++++++++---------
 fs/iso9660/Config.in       |   6 +-
 3 files changed, 378 insertions(+), 126 deletions(-)

diff --git a/board/shredos/embed/README b/board/shredos/embed/README
index 13ef99752d..e3370125c1 100644
--- a/board/shredos/embed/README
+++ b/board/shredos/embed/README
@@ -1,16 +1,16 @@
-This file is embedded into the GRUB bootloaders at build-time
-Helps GRUB find our ShredOS volume when it cannot (Ventoy BIOS)
+This file is embedded into the GRUB bootloaders at build-time.
+Helps GRUB find our ShredOS volume when it cannot (Ventoy BIOS).
 There is no point to put it anywhere on the USB - so don't do that.
 
 Keep consistent with BR2_TARGET_ROOTFS_ISO9660_GRUB2_EFI_IDENT_FILE
 when building any configurations that build both an ISO and the IMG.
 
 Do not use the version file as identification file though, because
-the ISO9660 filesystem does not have it (but has the needed grub.cfg),
+read-only ISO9660 filesystem doesn't have it (but has needed grub.cfg),
 so you should always use a unique file not otherwise used for anything.
 
 Also ensure it is in a location where users cannot delete it by accident.
 
-Note that contrary to the GNU manual the BIOS bootloader seems to need an
+Note that contrary to the GNU manual the BIOS bootloader seems to need the
 explicit "configfile" directive, otherwise the Buildroot static prefix takes
 precedence over the actual found volume path (which may be entirely different).
diff --git a/build_all_shredos.sh b/build_all_shredos.sh
index 086e602a0b..b7a398237d 100755
--- a/build_all_shredos.sh
+++ b/build_all_shredos.sh
@@ -1,68 +1,131 @@
 #!/bin/bash
+set -euo pipefail
 
 ################################################################################
-# Usage:
-#  FAIL_ON_ERROR=0|1 QUICK_BUILD=0|1 NEW_VERSION="STRING" ./build_all.sh
+# Usage: ./build_all_shredos.sh [x64|x32|all]
 #
-# Examples:
-#  ./build_all.sh
-#  FAIL_ON_ERROR=0 QUICK_BUILD=0 ./build_all.sh
-#  NEW_VERSION="2024.11_27_x86-64_0.38" ./build_all.sh
+# Arguments:
+#  x64   - Build only x86-64 configurations
+#  x32   - Build only i586 (32-bit) configurations
+#  all   - Build all configurations (64-bit first, then 32-bit)
 #
 # Environment Variables:
-#  FAIL_ON_ERROR - 0=continue on failure, 1=exit on first failure (default: 1)
-#  QUICK_BUILD - 0=full clean between configs, 1=grub2-rebuild only (default: 1)
-#  NEW_VERSION - Version string (default: prompts user & keeps current on ENTER)
+#  DRY_RUN=0|1      - Output all commands that would be executed (default: 0)
+#  PRE_CLEAN=0|1    - Do an initial 'make clean' before starting (default: 1)
+#  QUICK_BUILD=0|1  - Do not full rebuild for same architecture (default: 0)
+#  FAST_FAIL=0|1    - Exit on first configuration build failure (default: 1)
+#  NEW_VERSION=STR  - Set version string (default: prompts user)
+#
+# Examples:
+#  ./build_all_shredos.sh x64
+#  ./build_all_shredos.sh all
+#  QUICK_BUILD=1 ./build_all_shredos.sh x32
+#  NEW_VERSION="2024.11_27_x86-64_0.38" ./build_all_shredos.sh x64
 ################################################################################
 
-################################################################################
-# 0 = continue to the next configuration if one fails to build
-# 1 = exit the entire script if one configuration fails to build
-FAIL_ON_ERROR="${FAIL_ON_ERROR:-1}"
-################################################################################
-
-################################################################################
-# 0 = "make clean" between same architecture configs (much slower)
-# 1 = "make grub2-rebuild" between same architecture configs (much faster)
-QUICK_BUILD="${QUICK_BUILD:-1}"
-################################################################################
-
-################################################################################
+# Location of the version file:
 VERSION_FILE="board/shredos/fsoverlay/etc/shredos/version.txt"
 
-x64_configs=(
+# 64-bit configurations to build:
+X64_CONFIGS=(
 	"shredos_defconfig"
 	"shredos_img_defconfig"
 	"shredos_iso_defconfig"
 	"shredos_iso_aio_defconfig"
 )
 
-x32_configs=(
+# 32-bit configurations to build:
+X32_CONFIGS=(
 	"shredos_i586_defconfig"
 	"shredos_img_i586_defconfig"
 	"shredos_iso_i586_defconfig"
 	"shredos_iso_aio_i586_defconfig"
 )
+
+# Packages always needing rebuild between runs, even for the same architecture.
+# This only applies when QUICK_BUILD is enabled, otherwise rebuilds everything.
+ALWAYS_REBUILD_PKGS=(
+	"grub2"
+)
+
 ################################################################################
 
-set -e
-trap 'exit 1' SIGINT
-trap 'exit 1' SIGTERM
+DRY_RUN="${DRY_RUN:-0}"
+PRE_CLEAN="${PRE_CLEAN:-1}"
+QUICK_BUILD="${QUICK_BUILD:-0}"
+FAST_FAIL="${FAST_FAIL:-1}"
+NEW_VERSION="${NEW_VERSION:-}"
 
-x64_success=0
-x64_failed=0
-x32_success=0
-x32_failed=0
+X64_SUCCESS=0
+X64_FAILED=0
+X32_SUCCESS=0
+X32_FAILED=0
 
 GREEN="\033[0;32m"
+YELLOW="\033[0;33m"
 RED="\033[0;31m"
 RESET="\033[0m"
 
+FORCE_CLEAN=0
+
+print_usage() {
+	echo
+	echo "Usage: $0 [x64|x32|all]"
+	echo ""
+	echo "Arguments:"
+	echo "  x64   - Build only x86-64 configurations"
+	echo "  x32   - Build only i586 (32-bit) configurations"
+	echo "  all  - Build all configurations (64-bit first, then 32-bit)"
+	echo ""
+	echo "Environment Variables:"
+	echo "  DRY_RUN=0|1      - Output all commands that would be executed (default: 0)"
+	echo "  PRE_CLEAN=0|1    - Do an initial 'make clean' before starting (default: 1)"
+	echo "  QUICK_BUILD=0|1  - Do not full rebuild for same architecture (default: 0)"
+	echo "  FAST_FAIL=0|1    - Exit on first failure (default: 1)"
+	echo "  NEW_VERSION=STR  - Set version string (default: prompts user)"
+	echo ""
+	echo "Examples:"
+	echo "  $0 x64"
+	echo "  $0 all"
+	echo "  QUICK_BUILD=1 PRE_CLEAN=0 $0 x32"
+	echo
+}
+
+parse_arguments() {
+	if [ $# -eq 0 ]; then
+		printf "%b" "$RED"
+		echo "Error: Missing architecture argument"
+		printf "%b" "$RESET"
+		print_usage
+		exit 1
+	fi
+
+	BUILD_TARGET="$1"
+	case "$BUILD_TARGET" in
+		x64)
+			X32_CONFIGS=()
+			;;
+		x32)
+			X64_CONFIGS=()
+			;;
+		all)
+			;;
+		*)
+			printf "%b" "$RED"
+			echo "Error: Invalid architecture '$BUILD_TARGET'"
+			echo "Must be one of: x64, x32, all"
+			printf "%b" "$RESET"
+			print_usage
+			exit 1
+			;;
+	esac
+}
+
 prompt_version() {
-	local CURRENT_VERSION=""
+	local current_version=""
 
 	if [ -f "$VERSION_FILE" ]; then
-		CURRENT_VERSION=$(cat "$VERSION_FILE")
+		current_version=$(cat "$VERSION_FILE")
 	else
 		printf "%b" "$RED"
 		echo
@@ -77,8 +140,8 @@ prompt_version() {
 	if [ -z "$NEW_VERSION" ]; then
 		echo
 		echo "x86-64 and i586 will be replaced/switched around during builds (depending on architecture)"
-		read -rp "Enter new version or press ENTER to keep existing [${CURRENT_VERSION}]: " NEW_VERSION
-		[ -z "$NEW_VERSION" ] && NEW_VERSION="$CURRENT_VERSION"
+		read -rp "Enter new version or press ENTER to keep existing [${current_version}]: " NEW_VERSION
+		[ -z "$NEW_VERSION" ] && NEW_VERSION="$current_version"
 	fi
 
 	echo "$NEW_VERSION" > "$VERSION_FILE"
@@ -93,37 +156,48 @@ prompt_version() {
 }
 
 display_build_plan() {
-	local total_configs=$((${#x64_configs[@]} + ${#x32_configs[@]}))
-	
+	local total_configs=$((${#X64_CONFIGS[@]} + ${#X32_CONFIGS[@]}))
+
 	printf "%b" "$GREEN"
 	echo
 	echo "==============================================="
 	echo "PLANNING TO BUILD:"
 	echo "==============================================="
-	echo "Version:        $NEW_VERSION"
-	echo "Fail on Error:  $FAIL_ON_ERROR"
-	echo "Quick Build:    $QUICK_BUILD"
-	echo "Total Configs:  $total_configs"
+	echo "Version:                  $NEW_VERSION"
+	echo "Dry-Run:                  $DRY_RUN"
+	echo "Pre-Clean:                $PRE_CLEAN"
+	echo "Quick Build:              $QUICK_BUILD"
+	echo "Fast Failure:             $FAST_FAIL"
+	echo "Total Configurations:     $total_configs"
+	echo "Building Architectures:   $BUILD_TARGET"
 	echo "==============================================="
 	echo
 	printf "%b" "$RESET"
-	
-	if [ ${#x64_configs[@]} -gt 0 ]; then
-		echo "64-bit targets (${#x64_configs[@]}):"
-		for config in "${x64_configs[@]}"; do
+
+	if [ ${#X64_CONFIGS[@]} -gt 0 ]; then
+		echo "64-bit configurations (${#X64_CONFIGS[@]}):"
+		for config in "${X64_CONFIGS[@]}"; do
 			echo "  - $config"
 		done
 		echo
 	fi
-	
-	if [ ${#x32_configs[@]} -gt 0 ]; then
-		echo "32-bit targets (${#x32_configs[@]}):"
-		for config in "${x32_configs[@]}"; do
+
+	if [ ${#X32_CONFIGS[@]} -gt 0 ]; then
+		echo "32-bit configurations (${#X32_CONFIGS[@]}):"
+		for config in "${X32_CONFIGS[@]}"; do
 			echo "  - $config"
 		done
 		echo
 	fi
-	
+
+	if [ ${#ALWAYS_REBUILD_PKGS[@]} -gt 0 ]; then
+		echo "Packages that will be re-built between same-architecture runs (${#ALWAYS_REBUILD_PKGS[@]}):"
+		for package in "${ALWAYS_REBUILD_PKGS[@]}"; do
+			echo "  - $package"
+		done
+		echo
+	fi
+
 	printf "%b" "$GREEN"
 	echo "==============================================="
 	echo "Configurations to build can be amended inside the script."
@@ -135,94 +209,277 @@ display_build_plan() {
 replace_version() {
 	local from=$1
 	local to=$2
+
 	if [ -f "$VERSION_FILE" ]; then
-		sed -i "s/$from/$to/g" "$VERSION_FILE"
+		sed -i "s@$from@$to@g" "$VERSION_FILE"
 	fi
 }
 
+run_cmd() {
+    if [ "$DRY_RUN" -eq 1 ]; then
+        echo "[DRY_RUN] $*"
+    else
+        "$@"
+    fi
+}
+
 build_config() {
-	local config=$1
-	local arch=$2
+	local index="$1"
+	local config="$2"
+	local arch="$3"
 	local log_file="dist/${config}.log"
 
+    printf "%b" "$YELLOW"
 	echo
 	echo "============================================"
-	echo "Building $config ($arch)"
+	echo "Started: '$config' ($arch)"
 	echo "============================================"
 	echo
+	printf "%b" "$RESET"
 
-	if [ "$QUICK_BUILD" -eq 1 ]; then
-		make "$config"
-		make grub2-rebuild
+	# Build  | QuickBuild=1, PreClean=1  | QuickBuild=0, PreClean=1  | QuickBuild=1, PreClean=0  | QuickBuild=0, PreClean=0
+	# -------|---------------------------|---------------------------|---------------------------|---------------------------
+	# x64 #0 | config -> make            | config -> make            | config -> rebuild -> make | config -> rebuild -> make
+	# x64 #1 | config -> rebuild -> make | clean -> config -> make   | config -> rebuild -> make | clean -> config -> make
+	# x64 #2+| config -> rebuild -> make | clean -> config -> make   | config -> rebuild -> make | clean -> config -> make
+	# x32 #0 | clean -> config -> make   | clean -> config -> make   | clean -> config -> make   | clean -> config -> make
+	# x32 #1+| config -> rebuild -> make | clean -> config -> make   | config -> rebuild -> make | clean -> config -> make
+
+	if [ "$index" -ne 0 ] && [ "$QUICK_BUILD" -eq 1 ] && [ "$FORCE_CLEAN" -ne 1 ]; then
+		# If it's not the first configuration, and quick-build is enabled,
+		# and a clean is not otherwise forced, just rebuild necessary packages.
+		echo
+		echo "============================================"
+		echo "Loading configuration '$config' ($arch)..."
+		echo "============================================"
+		echo
+		if ! run_cmd make "$config"; then
+			build_config_failed "$config" "$arch" "$log_file"
+			return 1
+		fi
+		echo
+		echo "============================================"
+		echo "Rebuilding packages for '$config' ($arch)..."
+		echo "============================================"
+		echo
+		for pkg in "${ALWAYS_REBUILD_PKGS[@]}"; do
+			if ! run_cmd make "${pkg}-rebuild"; then
+				build_config_failed "$config" "$arch" "$log_file"
+				return 1
+			fi
+		done
 	else
-		make clean
-		make "$config"
+		if [ "$index" -ne 0 ] || [ "$FORCE_CLEAN" -eq 1 ]; then
+			# If it's not the first configuration, or the clean was forced
+			# (due to architecture change), clean the building environment.
+			echo
+			echo "============================================"
+			echo "Running 'make clean' for '$config' ($arch)..."
+			echo "============================================"
+			echo
+			if ! run_cmd make clean; then
+				build_config_failed "$config" "$arch" "$log_file"
+				return 1
+			fi
+		fi
+		echo
+		echo "============================================"
+		echo "Loading configuration '$config' ($arch)..."
+		echo "============================================"
+		echo
+		if ! run_cmd make "$config"; then
+			build_config_failed "$config" "$arch" "$log_file"
+			return 1
+		fi
+		if [ "$index" -eq 0 ] && [ "$PRE_CLEAN" -eq 0 ] && [ "$FORCE_CLEAN" -ne 1 ]; then
+			# If it's the first configuration in a deliberately unclean environment,
+			# and clean was not otherwise forced, at least rebuild the necessary packages.
+			echo
+			echo "============================================"
+			echo "Rebuilding packages for '$config' ($arch)..."
+			echo "============================================"
+			echo
+			for pkg in "${ALWAYS_REBUILD_PKGS[@]}"; do
+				if ! run_cmd make "${pkg}-rebuild"; then
+					build_config_failed "$config" "$arch" "$log_file"
+					return 1
+				fi
+			done
+		fi
 	fi
 
-	[ ! "$FAIL_ON_ERROR" -eq 1 ] && set +e
-	make 2>&1 | tee "$log_file"
-	local make_status=${PIPESTATUS[0]}
-	[ ! "$FAIL_ON_ERROR" -eq 1 ] && set -e
+	FORCE_CLEAN=0 # Reset previous dirty state
 
-	if [ "$make_status" -eq 0 ]; then
-		mv "$log_file" "dist/${config}-SUCCESS.log"
-
-		mkdir -p "dist/$config"
-		mv output/images/shredos*.iso "dist/$config/" 2>/dev/null || true
-		mv output/images/shredos*.img "dist/$config/" 2>/dev/null || true
-
-		printf "%b" "$GREEN"
+	echo
+	echo "============================================"
+	echo "Building '$config' ($arch)..."
+	echo "============================================"
+	echo
+	if run_cmd make 2>&1 | tee "$log_file"; then
 		echo
-		echo "==============================================="
-		echo "$config build ($arch) success"
-		echo "==============================================="
+		echo "============================================"
+		echo "Finishing '$config' ($arch)..."
+		echo "============================================"
 		echo
-		printf "%b\n" "$RESET"
-
-		if [ "$arch" = "x64" ]; then
-			((x64_success++))
-		else
-			((x32_success++))
-		fi
+		build_config_success "$config" "$arch" "$log_file"
 		return 0
 	else
-		mv "$log_file" "dist/${config}-FAILED.log"
+		echo
+		echo "============================================"
+		echo "Finishing '$config' ($arch)..."
+		echo "============================================"
+		echo
+		build_config_failed "$config" "$arch" "$log_file"
+		return 1
+	fi
+}
 
+print_summary() {
+	local total_success=$((X64_SUCCESS + X32_SUCCESS))
+	local total_failed=$((X64_FAILED + X32_FAILED))
+	local total_builds=$((total_success + total_failed))
+
+	echo
+	echo "============================================"
+	echo "BUILD SUMMARY"
+	echo "============================================"
+	echo "64-bit builds:  $X64_SUCCESS succeeded, $X64_FAILED failed"
+	echo "32-bit builds:  $X32_SUCCESS succeeded, $X32_FAILED failed"
+	echo "--------------------------------------------"
+	echo "Total:  $total_success succeeded, $total_failed failed (out of $total_builds)"
+	echo "--------------------------------------------"
+	echo "You will find all output files of the builds in the 'dist/' folder."
+	echo "============================================"
+	echo
+}
+
+build_config_success() {
+	local config="$1"
+	local arch="$2"
+	local log_file="$3"
+
+	if [ -f "$log_file" ]; then
+		run_cmd mv "$log_file" "dist/${config}-SUCCESS.log"
+	fi
+
+	run_cmd mkdir -p "dist/$config"
+	run_cmd mv output/images/shredos*.iso "dist/$config/" 2>/dev/null || true
+	run_cmd mv output/images/shredos*.img "dist/$config/" 2>/dev/null || true
+
+	printf "%b" "$GREEN"
+	echo
+	echo "==============================================="
+	echo "SUCCESS: '$config' ($arch)"
+	echo "==============================================="
+	echo
+	printf "%b" "$RESET"
+
+	if [ "$arch" = "x64" ]; then
+		((X64_SUCCESS++))
+	else
+		((X32_SUCCESS++))
+	fi
+}
+
+build_config_failed() {
+	local config="$1"
+	local arch="$2"
+	local log_file="$3"
+
+	if [ -f "$log_file" ]; then
+		run_cmd mv "$log_file" "dist/${config}-FAILED.log"
+	fi
+
+	printf "%b" "$RED"
+	echo
+	echo "==============================================="
+	echo "FAILURE: '$config' ($arch)"
+	echo "==============================================="
+	echo
+	printf "%b" "$RESET"
+
+	if [ "$arch" = "x64" ]; then
+		((X64_FAILED++))
+	else
+		((X32_FAILED++))
+	fi
+
+	if [ "$FAST_FAIL" -eq 1 ]; then
 		printf "%b" "$RED"
 		echo
 		echo "==============================================="
-		echo "$config build ($arch) failed"
+		echo "Fast Failure Mode is enabled - not proceeding..."
 		echo "==============================================="
 		echo
-		printf "%b\n" "$RESET"
-
-		if [ "$arch" = "x64" ]; then
-			((x64_failed++))
-		else
-			((x32_failed++))
-		fi
-		return 1
+		printf "%b" "$RESET"
+		exit 1
 	fi
 }
 
 ################################################################################
 
+parse_arguments "$@"
 prompt_version
 display_build_plan
 
-echo "Starting these builds in 10 seconds... (press CTRL+C to cancel)"
+if [ "$DRY_RUN" -eq 1 ]; then
+	printf "%b" "$YELLOW"
+	echo
+	echo "==============================================="
+	echo "DRY RUN - NO ACTUAL CHANGES WILL BE MADE"
+	echo "DISREGARD WARNINGS ABOUT 'MAKE CLEAN' ETC..."
+	echo "==============================================="
+	echo
+	printf "%b" "$RESET"
+fi
+
+if [ "$PRE_CLEAN" -eq 1 ]; then
+	printf "%b" "$RED"
+	echo
+	echo "==============================================="
+	echo "Beware - WILL run a MAKE CLEAN before starting building!"
+	echo "Press ENTER in the next 10 seconds to skip this step..."
+	echo "or otherwise (if you want to MAKE CLEAN) - just wait..."
+	echo "==============================================="
+	echo
+	printf "%b" "$RESET"
+	
+	if read -rt 10; then
+		PRE_CLEAN=0
+		echo "Skipped cleaning the building stage (no 'make clean')..."
+	fi
+fi
+
+printf "%b" "$YELLOW"
+echo
+echo "==============================================="
+echo "Starting build in 10 seconds... (press CTRL+C to cancel)"
+if [ "$PRE_CLEAN" -eq 1 ]; then
+	printf "%b" "$RESET"
+	printf "%b" "$RED"
+	echo "Beware - WILL run a MAKE CLEAN before starting building!"
+	printf "%b" "$RESET"
+	printf "%b" "$YELLOW"
+fi
+echo "==============================================="
+echo
+printf "%b" "$RESET"
+
 sleep 10
 
-echo "Running 'make clean' on the building environment..."
-make clean
+if [ "$PRE_CLEAN" -eq 1 ]; then
+	echo "Running 'make clean' on the building environment..."
+	run_cmd make clean
+fi
 
 echo "Removing and recreating 'dist/' folder (if it exists)..."
-rm -r dist || true
-mkdir -p dist
+run_cmd rm -r dist || true
+run_cmd mkdir -p dist
 
 echo "Starting to build..."
+trap 'print_summary' EXIT
 
-if [ ${#x64_configs[@]} -gt 0 ]; then
+if [ ${#X64_CONFIGS[@]} -gt 0 ]; then
 	echo
 	echo "==============================================="
 	echo "Starting 64-bit builds..."
@@ -230,14 +487,19 @@ if [ ${#x64_configs[@]} -gt 0 ]; then
 	echo
 	replace_version "i586" "x86-64"
 
-	for config in "${x64_configs[@]}"; do
-		build_config "$config" "x64" || true
+	CFG_INDEX=0
+	for config in "${X64_CONFIGS[@]}"; do
+		build_config "$CFG_INDEX" "$config" "x64" || true
+		((++CFG_INDEX))
 	done
 fi
 
-make clean
+if [ ${#X32_CONFIGS[@]} -gt 0 ]; then
+	if [ ${#X64_CONFIGS[@]} -gt 0 ]; then
+		run_cmd make clean
+		FORCE_CLEAN=1 # Need this for architecture change
+	fi
 
-if [ ${#x32_configs[@]} -gt 0 ]; then
 	echo
 	echo "==============================================="
 	echo "Starting 32-bit builds..."
@@ -245,29 +507,15 @@ if [ ${#x32_configs[@]} -gt 0 ]; then
 	echo
 	replace_version "x86-64" "i586"
 
-	for config in "${x32_configs[@]}"; do
-		build_config "$config" "x32" || true
+	CFG_INDEX=0
+	for config in "${X32_CONFIGS[@]}"; do
+		build_config "$CFG_INDEX" "$config" "x32" || true
+		((++CFG_INDEX))
 	done
 fi
 
-total_success=$((x64_success + x32_success))
-total_failed=$((x64_failed + x32_failed))
-total_builds=$((total_success + total_failed))
-
-echo
-echo "============================================"
-echo "BUILD SUMMARY"
-echo "============================================"
-echo "64-bit builds:  $x64_success succeeded, $x64_failed failed"
-echo "32-bit builds:  $x32_success succeeded, $x32_failed failed"
-echo "--------------------------------------------"
-echo "Total:  $total_success succeeded, $total_failed failed (out of $total_builds)"
-echo "--------------------------------------------"
-echo "You will find all output files of the builds in the 'dist/' folder."
-echo "============================================"
-echo
-
-if [ $total_failed -gt 0 ]; then
+TOTAL_FAILED=$((X64_FAILED + X32_FAILED))
+if [ "$TOTAL_FAILED" -gt 0 ]; then
 	exit 1
 else
 	exit 0
diff --git a/fs/iso9660/Config.in b/fs/iso9660/Config.in
index 1e2424db2b..690586de60 100644
--- a/fs/iso9660/Config.in
+++ b/fs/iso9660/Config.in
@@ -106,13 +106,17 @@ config BR2_TARGET_ROOTFS_ISO9660_GRUB2_EFI_BOOT_MENU
 	default "fs/iso9660/efigrub.cfg"
 	help
 	  Use this option to provide a custom GRUB2 configuration
-	  file (grub.cfg), embedded both in the EFI partition and the
+	  file (grub.cfg), copied both to the EFI partition and the
 	  ISO9660 filesystem EFI-structure (for an EFI bootloader to find).
 
 	  It will usually contain a "search" and "source" directive to find
 	  the ISO9660 filesystem containing a common (BIOS) GRUB2 configuration.
 	  Alternatively, 'set root=(cd0)' and other such quirks are possible here.
 
+	  This is specifically for directives required for ISO9660 builds, for
+	  baking an EFI search config into the common GRUB image (often better)
+	  check out instead the GRUB2 setting: BR2_TARGET_GRUB2_BUILTIN_CONFIG_EFI
+
 	  Note that any string __EFI_ID_FILE__ will automatically be
 	  replaced with the BR2_TARGET_ROOTFS_ISO9660_GRUB2_EFI_IDENT_FILE.