kernel: Add TARGET_FORCE_PREBUILT_KERNEL flag
* TARGET_FORCE_PREBUILT_KERNEL should be useful when you don't have ready kernel sources (OEM releasing broken sources or releasing them lately)
* It lets you use kernel sources for userspace generated headers (generated_kernel_headers) while keeping using prebuilt kernel
* Keep in mind that generated kernel headers may not align with the ABI of kernel you're including
* This commit also partially revert commit a836d79, where TARGET_KERNEL_SOURCE would have been unset if TARGET_PREBUILT_KERNEL was defined (we already check in kernel.mk if kernel sources are present anyway)
Change-Id: I84acae890dabb5b9dbd48143ad58f6420c0cef75
diff --git a/build/tasks/kernel.mk b/build/tasks/kernel.mk
index a810fd9..6f18df8 100644
--- a/build/tasks/kernel.mk
+++ b/build/tasks/kernel.mk
@@ -1,5 +1,5 @@
# Copyright (C) 2012 The CyanogenMod Project
-# (C) 2017-2020 The LineageOS Project
+# (C) 2017-2021 The LineageOS Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
@@ -61,6 +61,9 @@
# modules in system instead of vendor
# NEED_KERNEL_MODULE_VENDOR_OVERLAY = Optional, if true, install kernel
# modules in vendor_overlay instead of vendor
+#
+# TARGET_FORCE_PREBUILT_KERNEL = Optional, use TARGET_PREBUILT_KERNEL even if
+# kernel sources are present
ifneq ($(TARGET_NO_KERNEL),true)
ifneq ($(TARGET_NO_KERNEL_OVERRIDE),true)
@@ -153,8 +156,27 @@
$(warning **********************************************************)
$(error "NO KERNEL CONFIG")
else
- FULL_KERNEL_BUILD := true
- KERNEL_BIN := $(TARGET_PREBUILT_INT_KERNEL)
+ ifeq ($(filter RELEASE NIGHTLY SNAPSHOT EXPERIMENTAL,$(LINEAGE_BUILDTYPE)),)
+ $(error "PREBUILT KERNEL IS NOT ALLOWED ON OFFICIAL BUILDS!")
+ else
+ ifneq ($(TARGET_FORCE_PREBUILT_KERNEL),)
+ $(warning **********************************************************)
+ $(warning * Kernel source found and configuration was defined, *)
+ $(warning * but prebuilt kernel is being forced. *)
+ $(warning * While this is likely intentional, *)
+ $(warning * it is NOT SUPPORTED WHATSOEVER. *)
+ $(warning * Generated kernel headers may not align with *)
+ $(warning * the ABI of kernel you're including. *)
+ $(warning * Please unset TARGET_FORCE_PREBUILT_KERNEL *)
+ $(warning * to build the kernel from source. *)
+ $(warning **********************************************************)
+ FULL_KERNEL_BUILD := false
+ KERNEL_BIN := $(TARGET_PREBUILT_KERNEL)
+ else
+ FULL_KERNEL_BUILD := true
+ KERNEL_BIN := $(TARGET_PREBUILT_INT_KERNEL)
+ endif
+ endif
endif
endif