apollo-kernel: refactor for apollo patches

* refactor esd can driver related files into esdcan.patch
* refactor other changes into pre_rt.patch

Author: quning18

README.md

@@ -5,7 +5,7 @@ In the first release, we add the most popular solution, Linux Kernel, under the
 
 ## Linux Kernel
 
-Apollo Linux Kernel is based on Linux Kernel 4.4.32 with some modifications.
+Apollo Linux Kernel is based on official [Linux Kernel 4.4.32](https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.4.32.tar.gz) with some modifications.
 
 ### What is the difference
 
@@ -15,6 +15,8 @@ Apollo Linux Kernel is based on Linux Kernel 4.4.32 with some modifications.
   * Double free in the inet_csk_clone_lock function patch (https://bugzilla.redhat.com/show_bug.cgi?id=1450972)
   * Other cve security patches
 
+[Kernel config files](https://github.com/ApolloAuto/apollo-kernel/tree/master/linux/configs) are modified for Apollo based on Ubuntu's config-4.4.0-X-generic.
+
 The Apollo team would like to thank everybody in the open source community. The GitHub apollo-kernel/linux is based on Linux. Currently, Apollo team maintains this repository. In near future, we’ll send patches back to Linux community.
 
 ### Add ESD CAN Support

linux/Makefile

@@ -1,7 +1,7 @@
 VERSION = 4
 PATCHLEVEL = 4
 SUBLEVEL = 32
-EXTRAVERSION = -apollo-1
+EXTRAVERSION =
 NAME = Blurry Fish Butt
 
 # *DOCUMENTATION*

linux/build.sh

@@ -132,6 +132,15 @@ function kernel_cleanall() {
 }
 
 function kernel_patch() {
+    # patch pre_rt.patch
+    grep '#res' scripts/setlocalversion > /dev/null
+    if [ $? -ne 0 ]; then
+        k_patch patches/pre_rt.patch
+    fi
+    # patch esdcan
+    if [ -d drivers/esdcan ]; then
+        k_patch patches/esdcan.patch
+    fi
     # patch e1000e.patch
     grep E1000_DEV_ID_PCH_LBG_I219_LM3 drivers/net/ethernet/intel/e1000e/hw.h > /dev/null
     if [ $? -ne 0 ]; then

linux/drivers/Kconfig

@@ -198,6 +198,4 @@ source "drivers/hwtracing/intel_th/Kconfig"
 
 source "drivers/fpga/Kconfig"
 
-source "drivers/esdcan/Kconfig"
-
 endmenu

linux/drivers/Makefile

@@ -172,4 +172,3 @@ obj-$(CONFIG_STM)		+= hwtracing/stm/
 obj-$(CONFIG_ANDROID)		+= android/
 obj-$(CONFIG_NVMEM)		+= nvmem/
 obj-$(CONFIG_FPGA)		+= fpga/
-obj-$(CONFIG_ESDCAN)		+= esdcan/

linux/drivers/esdcan/Kconfig

@@ -1520,7 +1520,7 @@ void rt_mutex_destroy(struct rt_mutex *lock)
 #endif
 }
 
-EXPORT_SYMBOL(rt_mutex_destroy);
+EXPORT_SYMBOL_GPL(rt_mutex_destroy);
 
 /**
  * __rt_mutex_init - initialize the rt lock