From 63d15f7dfc447e431a22285126ab822461c9337e Mon Sep 17 00:00:00 2001
From: Dominique Martinet <dominique.martinet@cea.fr>
Date: Wed, 27 Feb 2019 17:22:02 +0900
Subject: [PATCH] CMake Kbuild: fail at cmake time if KERNEL_DIR is missing

Change-Id: I66660718841d05003b87995d68bec728aa0db9ba
---
 cmake/modules/Kbuild.cmake | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/cmake/modules/Kbuild.cmake b/cmake/modules/Kbuild.cmake
index cec3344a..bcc6b98f 100644
--- a/cmake/modules/Kbuild.cmake
+++ b/cmake/modules/Kbuild.cmake
@@ -78,6 +78,10 @@ endif(ENABLE_WERROR)
 	# the native build system do these checks, if possible at all...
 	add_custom_command(OUTPUT kmod_always_rebuild COMMAND touch kmod_always_rebuild)
 
+	if (NOT EXISTS "${KERNEL_DIR}/Makefile")
+		message(FATAL_ERROR "${KERNEL_DIR} does not contain a Makefile and is probably missing. install kernel development package or set the KERNEL_DIR variable")
+	endif()
+
 	add_custom_command(
 		OUTPUT "${MODULE_NAME}.ko"
 			"Module.symvers"