scripts/kernel-test: add KERNEL_SKIP_SMOKE_TEST

Speed up local test cycles by not running the smoke test every time.

Change-Id: I505b74e8c9b221655a97c5464f6fe4f21204a894

README.md

@@ -84,6 +84,8 @@ Environment variables:
 * `KERNEL_BRANCH` branch to checkout (default: master)
 * `KERNEL_SKIP_REBUILD`: set to 1 to not build the kernel again if already
   built with `KERNEL_BUILD=1`
+* `KERNEL_SKIP_SMOKE_TEST`: don't boot up the kernel in QEMU once before
+  running the testsuite
 
 The OBS repository mirror consists of
 `${OSMOCOM_REPO_MIRROR}/${OSMOCOM_REPO_PATH}/${OSMOCOM_REPO_VERSION}`,

jenkins-common.sh

@@ -452,6 +452,7 @@ kernel_test_prepare() {
 		-e "KERNEL_REMOTE_NAME=$KERNEL_REMOTE_NAME" \
 		-e "KERNEL_URL=$KERNEL_URL" \
 		-e "KERNEL_SKIP_REBUILD=$KERNEL_SKIP_REBUILD" \
+		-e "KERNEL_SKIP_SMOKE_TEST=$KERNEL_SKIP_SMOKE_TEST" \
 		"$@" \
 		"$docker_image" \
 		"/kernel-test/prepare.sh"

scripts/kernel-test/prepare.sh

@@ -20,4 +20,6 @@ else
 	cp /boot/vmlinuz-* /cache/kernel-test/linux
 fi
 
-kernel_smoke_test
+if [ "$KERNEL_SKIP_SMOKE_TEST" != 1 ]; then
+	kernel_smoke_test
+fi