1 files changed, 8 insertions, 0 deletions
diff --git a/kern b/kern
index cdd2d8d..0f19772 100755
--- a/kern
+++ b/kern
@@ -13,6 +13,10 @@ errx() {
 	exit 1
 }
 
+need_kernel_source() {
+	test -r Kbuild -a -r Kconfig || errx "current directory does not contain a kernel source tree, refusing"
+}
+
 has_boot_mount() {
 	awk '{print $2}' /etc/fstab | grep -q ^/boot$
 }
@@ -65,6 +69,7 @@ set_kernel() {
 }
 
 config_kernel() {
+	need_kernel_source
 	host=${1:-$(hostname)}
 
 	test -d "$KERNFRAG" || errx "No such file or directory: $KERNFRAG"
@@ -76,6 +81,7 @@ config_kernel() {
 }
 
 diff_kernel() {
+	need_kernel_source
 	diff=${1:-$(get_running_config)}
 
 	if command -v git >/dev/null; then
@@ -86,10 +92,12 @@ diff_kernel() {
 }
 
 build_kernel() {
+	need_kernel_source
 	make -j"$(nproc)"
 }
 
 install_kernel() {
+	need_kernel_source
 	mount_boot_on_demand
 	sudo make install modules_install
 }