[build] support custom build config for external platform

config/esp32/args.gni

@@ -24,8 +24,6 @@ chip_ble_project_config_include = ""
 mbedtls_target = "//mbedtls:mbedtls"
 lwip_platform = "external"
 
-chip_build_tests = true
-
 #Enabling this causes some error
 #chip_inet_config_enable_tun_endpoint = false
 chip_inet_config_enable_tcp_endpoint = true

config/esp32/components/chip/CMakeLists.txt

@@ -91,6 +91,10 @@ if(CONFIG_ENABLE_PW_RPC)
     chip_gn_arg_append("pw_build_LINK_DEPS"                 "[\"\$dir_pw_assert:impl\", \"\$dir_pw_log:impl\"]")
 endif()
 
+if (CONFIG_BUILD_CHIP_TESTS)
+    chip_gn_arg_bool("chip_build_tests"     "true")
+endif()
+
 if (NOT CONFIG_USE_MINIMAL_MDNS)
     chip_gn_arg_append("chip_mdns"                          "\"platform\"")
 endif()
@@ -116,6 +120,11 @@ if (CONFIG_ENABLE_ROTATING_DEVICE_ID)
     chip_gn_arg_append("chip_enable_rotating_device_id"            "true")
 endif()
 
+if (CONFIG_CHIP_ENABLE_EXTERNAL_PLATFORM)
+    chip_gn_arg_append("chip_device_platform"   "\"external\"")
+    chip_gn_arg_append("chip_platform_target"   "\"${CONFIG_CHIP_EXTERNAL_PLATFORM_TARGET}\"")
+endif()
+
 set(args_gn_input "${CMAKE_CURRENT_BINARY_DIR}/args.gn.in")
 file(GENERATE OUTPUT "${args_gn_input}" CONTENT "${chip_gn_args}")
 

config/esp32/components/chip/Kconfig

@@ -102,6 +102,12 @@ menu "CHIP Core"
             help
                 Matter spec is based on IPv6 communication only. Enabling this option may save some flash/ram.
 
+        config BUILD_CHIP_TESTS
+            bool "Build CHIP tests"
+            default "y"
+            help
+                Build CHIP test binaries.
+
         # TODO: add log level selection
 
     endmenu # "General Options"
@@ -748,4 +754,18 @@ menu "CHIP Device Layer"
 
     endmenu
 
+    menu "External Platform"
+        config CHIP_ENABLE_EXTERNAL_PLATFORM
+            bool "Enable external platform layer"
+            default n
+            help
+                Use external platform layer to override the default ESP32 platform in Matter SDK.
+
+        config CHIP_EXTERNAL_PLATFORM_TARGET
+            string "The external platform target"
+            depends on CHIP_ENABLE_EXTERNAL_PLATFORM
+            help
+                The gn target of the external platform.
+    endmenu
+
 endmenu

src/ble/BUILD.gn

@@ -51,6 +51,7 @@ source_set("ble_config_header") {
 
   public_deps = [
     ":ble_buildconfig",
+    "${chip_root}/src/platform:platform_buildconfig",
     "${chip_root}/src/system:system_config_header",
   ]
 }

src/ble/BleConfig.h

@@ -37,6 +37,7 @@
 
 #if CHIP_HAVE_CONFIG_H
 #include <ble/BleBuildConfig.h>
+#include <platform/CHIPDeviceBuildConfig.h>
 #endif
 
 #include <system/SystemConfig.h>

src/platform/BUILD.gn

@@ -36,7 +36,7 @@ if (chip_device_platform == "linux" && chip_mdns != "none") {
   }
 }
 
-if (chip_device_platform != "none") {
+if (chip_device_platform != "none" && chip_device_platform != "external") {
   declare_args() {
     # Extra header to include in CHIPDeviceConfig.h for project.
     chip_device_project_config_include = ""
@@ -244,7 +244,7 @@ if (chip_device_platform != "none") {
           [ "CHIP_DEVICE_CONFIG_ENABLE_WPA=${chip_device_config_enable_wpa}" ]
     }
   }
-} else {
+} else if (chip_device_platform == "none") {
   buildconfig_header("platform_buildconfig") {
     header = "CHIPDeviceBuildConfig.h"
     header_dir = "platform"
@@ -258,6 +258,10 @@ if (chip_device_platform != "none") {
       defines += [ "EXTERNAL_KEYVALUESTOREMANAGERIMPL_HEADER=\"controller/java/AndroidKeyValueStoreManagerImpl.h\"" ]
     }
   }
+} else {
+  group("platform_buildconfig") {
+    public_deps = [ "${chip_platform_target}:platform_buildconfig" ]
+  }
 }
 
 if (chip_device_platform != "none") {

src/system/BUILD.gn

@@ -115,7 +115,10 @@ source_set("system_config_header") {
     "${chip_root}/src:includes",
   ]
 
-  public_deps = [ ":system_buildconfig" ]
+  public_deps = [
+    ":system_buildconfig",
+    "${chip_root}/src/platform:platform_buildconfig",
+  ]
 
   if (target_cpu != "esp32") {
     if (chip_system_config_use_lwip) {

src/system/SystemConfig.h

@@ -38,6 +38,7 @@
 
 /* Platform include headers */
 #if CHIP_HAVE_CONFIG_H
+#include <platform/CHIPDeviceBuildConfig.h>
 #include <system/SystemBuildConfig.h>
 #endif