From 56e71a1ca79eddae3769a5e2d63ab94d79a02866 Mon Sep 17 00:00:00 2001
From: XiNGRZ <chenxingyu92@gmail.com>
Date: Wed, 13 Oct 2021 01:59:42 +0800
Subject: [PATCH] build: Add support of generating kernel includes for prebuilt
 kernels

For prebuilt kernels, point TARGET_KERNEL_HEADERS_SOURCE to the dummy
kernel source used to generate headers for HALs.

Change-Id: I95a1050a7e0650faac112724b7bd6a300cdb6e4a
---
 build/soong/Android.bp      | 4 ++--
 config/BoardConfigKernel.mk | 7 +++++++
 config/BoardConfigSoong.mk  | 2 +-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/build/soong/Android.bp b/build/soong/Android.bp
index daad30e..78123c5 100644
--- a/build/soong/Android.bp
+++ b/build/soong/Android.bp
@@ -21,7 +21,7 @@ twrp_generator {
     name: "generated_kernel_includes",
 
     // The headers make command
-    cmd: "$(PATH_OVERRIDE_SOONG) $(KERNEL_MAKE_CMD) $(KERNEL_MAKE_FLAGS) -C $(TARGET_KERNEL_SOURCE) O=$(KERNEL_BUILD_OUT_PREFIX)$(genDir) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) headers_install",
+    cmd: "$(PATH_OVERRIDE_SOONG) $(KERNEL_MAKE_CMD) $(KERNEL_MAKE_FLAGS) -C $(TARGET_KERNEL_HEADERS_SOURCE) O=$(KERNEL_BUILD_OUT_PREFIX)$(genDir) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) headers_install",
 
     // Directories that can be imported by a cc_* module generated_headers property
     export_include_dirs: [
@@ -32,7 +32,7 @@ twrp_generator {
     ],
 
     // Sources for dependency tracking
-    dep_root: "$(TARGET_KERNEL_SOURCE)",
+    dep_root: "$(TARGET_KERNEL_HEADERS_SOURCE)",
     dep_files: [
         "Makefile",
         "include/**/*",
diff --git a/config/BoardConfigKernel.mk b/config/BoardConfigKernel.mk
index 18ce0bf..53c90b2 100644
--- a/config/BoardConfigKernel.mk
+++ b/config/BoardConfigKernel.mk
@@ -20,6 +20,9 @@
 #
 #   TARGET_KERNEL_SOURCE               = Kernel source dir, optional, defaults
 #                                          to kernel/$(TARGET_DEVICE_DIR)
+#   TARGET_KERNEL_HEADERS_SOURCE       = Kernel headers dir, in order to generate kernel
+#                                          includes for prebuilt kernels, optional, defaults
+#                                          to TARGET_KERNEL_SOURCE
 #   TARGET_KERNEL_ADDITIONAL_FLAGS     = Additional make flags, optional
 #   TARGET_KERNEL_ARCH                 = Kernel Arch
 #   TARGET_KERNEL_CROSS_COMPILE_PREFIX = Compiler prefix (e.g. arm-eabi-)
@@ -45,6 +48,10 @@ ifneq ($(TARGET_PREBUILT_KERNEL),)
 TARGET_KERNEL_SOURCE :=
 endif
 
+ifneq ($(TARGET_KERNEL_SOURCE),)
+TARGET_KERNEL_HEADERS_SOURCE := $(TARGET_KERNEL_SOURCE)
+endif
+
 TARGET_KERNEL_ARCH := $(strip $(TARGET_KERNEL_ARCH))
 ifeq ($(TARGET_KERNEL_ARCH),)
 KERNEL_ARCH := $(TARGET_ARCH)
diff --git a/config/BoardConfigSoong.mk b/config/BoardConfigSoong.mk
index 45e677b..6e39d85 100644
--- a/config/BoardConfigSoong.mk
+++ b/config/BoardConfigSoong.mk
@@ -9,7 +9,7 @@ EXPORT_TO_SOONG := \
     KERNEL_MAKE_FLAGS \
     PATH_OVERRIDE_SOONG \
     TARGET_KERNEL_CONFIG \
-    TARGET_KERNEL_SOURCE
+    TARGET_KERNEL_HEADERS_SOURCE
 
 # Setup SOONG_CONFIG_* vars to export the vars listed above.
 # Documentation here: