From a3cae20caab84efbf71e423fb75a49fa81ef0f96 Mon Sep 17 00:00:00 2001
From: Vidal Gerard <vidal@debian-BULLSEYE-live-builder-AMD64>
Date: Wed, 29 Oct 2025 16:48:35 +0100
Subject: [PATCH] Added triple choice for kernel : build download or uselocal

---
 README.md                |  2 +-
 bootstrap.d/13-kernel.sh | 30 +++++++++++++++++++++---------
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 9e1578b..b7f0983 100644
--- a/README.md
+++ b/README.md
@@ -232,7 +232,7 @@ The following static networking parameters are only supported if `ENABLE_WIFI_DH
 
 |Option|Value|default value|value format|desciption|
 |---|---|---|---|---|
-|BUILD_KERNEL||true|`true`\|`false`|Build and install the latest RPi 0/1/2/3/4 Linux kernel. The default RPi 0/1/2/3/ kernel configuration is used most of the time. ENABLE_NEXMON - Changes Kernel Source to [https://github.com/Re4son/](Kali Linux Kernel) Precompiled 32bit kernel for RPI0/1/2/3 by [https://github.com/hypriot/](hypriot) Precompiled 64bit kernel for RPI3/4 by [https://github.com/sakaki-/](sakaki)|
+|BUILD_KERNEL||build|`build`\|`uselocal`\|`download`|Build and install the latest RPi 0/1/2/3/4 Linux kernel. The default RPi 0/1/2/3/ kernel configuration is used most of the time. ENABLE_NEXMON - Changes Kernel Source to [https://github.com/Re4son/](Kali Linux Kernel) Precompiled 32bit kernel for RPI0/1/2/3 by [https://github.com/hypriot/](hypriot) Precompiled 64bit kernel for RPI3/4 by [https://github.com/sakaki-/](sakaki)|
 |CROSS_COMPILE|string|||This sets the cross-compile environment for the compiler. Set by RPI_MODEL|
 |KERNEL_ARCH|string|||This sets the kernel architecture for the compiler. Set by RPI_MODEL|
 |KERNEL_IMAGE|string|||Name of the image file in the boot partition. Set by RPI_MODEL|
diff --git a/bootstrap.d/13-kernel.sh b/bootstrap.d/13-kernel.sh
index c5fff0a..253b3c2 100644
--- a/bootstrap.d/13-kernel.sh
+++ b/bootstrap.d/13-kernel.sh
@@ -14,7 +14,9 @@ if [ "$ENABLE_NEXMON" = true ] ; then
 fi
 
 # Fetch and build latest raspberry kernel
-if [ "$BUILD_KERNEL" = true ] ; then
+case "$BUILD_KERNEL" in
+  "build")
+#if [ "$BUILD_KERNEL" = build ] ; then
   # Setup source directory
   mkdir -p "${KERNEL_DIR}"
 
@@ -798,7 +800,9 @@ if [ "$BUILD_KERNEL" = true ] ; then
       chroot_exec ln -sf /usr/src/linux "/lib/modules/${KERNEL_VERSION}/source"
     fi
   fi
+  ;;
 
+"download")
 else # BUILD_KERNEL=false
   if [ "$SET_ARCH" = 64 ] ; then
     if [ "$RPI_MODEL" = 3 ] || [ "$RPI_MODEL" = 3P ] ; then
@@ -875,12 +879,20 @@ else # BUILD_KERNEL=false
     rm -fr "${temp_dir}"
 	rm -f "${R}"/tmp/kernel.deb
   fi
-
-  # Check if kernel installation was successful
-  KERNEL="$(ls -1 "${R}"/boot/firmware/kernel* | sort | tail -n 1)"
-  if [ -z "$KERNEL" ] ; then
-    echo "error: kernel installation failed! (/boot/kernel* not found)"
-    cleanup
-    exit 1
-  fi
 fi
+  ;;
+
+"uselocal")
+  echo "using local kernel previous run"
+  ;;
+  
+esac
+
+# Check if kernel installation was successful
+KERNEL="$(ls -1 "${R}"/boot/firmware/kernel* | sort | tail -n 1)"
+if [ -z "$KERNEL" ] ; then
+  echo "error: kernel installation failed! (/boot/kernel* not found)"
+  cleanup
+  exit 1
+fi
+#fi