pkg/esp32_sdk_libs: add ESP SDK libraries as package

The vendor binary libraries of ESP-IDF are provided as a separate GIT repository. These libraries are defined as separate package for two reasons: 1. RIOT packages don't support to clone GIT repositories recursively; 2. ESP-IDF pulls a lot of other GIT repositories that are not needed when it is cloned recursively.

cpu/esp32/Kconfig

@@ -19,6 +19,7 @@ config CPU_FAM_ESP32
     select HAS_PERIPH_ADC_CTRL
 
     select PACKAGE_ESP32_SDK if TEST_KCONFIG
+    select PACKAGE_ESP32_SDK_LIBS if TEST_KCONFIG
     select MODULE_PERIPH_RTT if HAS_PERIPH_RTT && MODULE_PM_LAYERED
     select MODULE_RTT_RTC if HAS_PERIPH_RTT && MODULE_PERIPH_RTC
     select MODULE_PS if MODULE_SHELL

cpu/esp32/Makefile.dep

@@ -3,6 +3,8 @@
 include $(RIOTCPU)/esp_common/Makefile.dep
 
 USEPKG += esp32_sdk
+USEPKG += esp32_sdk_libs
+
 USEMODULE += esp_idf_driver
 USEMODULE += esp_idf_esp32
 USEMODULE += esp_idf_soc

pkg/Kconfig

@@ -18,6 +18,7 @@ rsource "driver_sx126x/Kconfig"
 rsource "elk/Kconfig"
 rsource "emlearn/Kconfig"
 rsource "esp32_sdk/Kconfig"
+rsource "esp32_sdk_libs/Kconfig"
 rsource "esp8266_sdk/Kconfig"
 rsource "fff/Kconfig"
 rsource "gecko_sdk/Kconfig"

pkg/esp32_sdk_libs/Kconfig

@@ -0,0 +1,13 @@
+# Copyright (c) 2021 Gunar Schorcht
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+config PACKAGE_ESP32_SDK_LIBS
+    bool "ESP32 SDK libraries for the ESP32 MCU support"
+    depends on TEST_KCONFIG
+    depends on HAS_ARCH_ESP32
+    help
+        Vendor SDK libraries for ESP32 MCU support by Espressif

pkg/esp32_sdk_libs/Makefile

@@ -0,0 +1,39 @@
+PKG_NAME=esp32_sdk_libs
+PKG_URL=https://github.com/espressif/esp32-wifi-lib
+# This is a version in the v3.1 beta1 release branch
+PKG_VERSION=534a9b14101af90231d40a4f94924d67bc848d5f
+PKG_LICENSE=Apache-2.0
+
+include $(RIOTBASE)/pkg/pkg.mk
+
+ESP32_SDK_DIR = $(PKGDIRBASE)/esp32_sdk
+
+# Directory where we place the libraries and headers.
+ESP32_SDK_BUILD_DIR = $(ESP32_SDK_DIR)/build-libs
+
+# We need to place all binary libraries shipped with the SDK in a common
+# directory.
+ESP32_SDK_COMPONENT_LIBS = \
+    libcoexist.a \
+    libcore.a \
+    libespnow.a \
+    libmesh.a \
+    libnet80211.a \
+    libphy.a \
+    libpp.a \
+    librtc.a \
+    libsmartconfig.a \
+    libwpa.a \
+    libwpa2.a \
+    libwps.a
+
+ESP32_SDK_LIBS = $(addprefix $(ESP32_SDK_BUILD_DIR)/, $(ESP32_SDK_COMPONENT_LIBS))
+
+all: $(ESP32_SDK_LIBS)
+
+$(ESP32_SDK_BUILD_DIR):
+	$(Q)mkdir -p $(ESP32_SDK_BUILD_DIR)
+
+$(ESP32_SDK_BUILD_DIR)/lib%.a: \
+    $(PKG_SOURCE_DIR)/lib%.a | $(ESP32_SDK_BUILD_DIR)
+	$(Q)cp $? $(ESP32_SDK_BUILD_DIR)

pkg/esp32_sdk_libs/Makefile.dep

@@ -0,0 +1,2 @@
+# This package can only be used with the ESP32 CPU
+FEATURES_REQUIRED += arch_esp32

pkg/esp32_sdk_libs/Makefile.include

@@ -0,0 +1,13 @@
+# Directory with the SDK source checkout. Some modules in the cpu/esp32 use
+# internal parts of the SDK and for that they need access to the
+# ESP32_SDK_DIR path.
+export ESP32_SDK_DIR = $(PKGDIRBASE)/esp32_sdk
+
+# Directory where we built the modified libraries and headers.
+ESP32_SDK_BUILD_DIR ?= $(ESP32_SDK_DIR)/build-libs
+
+# Modified binary libraries are built here in the Makefile.
+LINKFLAGS += -L$(ESP32_SDK_BUILD_DIR)
+
+# esp32_sdk_libs doesn't generate any .a
+PSEUDOMODULES += esp32_sdk_libs

pkg/esp32_sdk_libs/doc.txt

@@ -0,0 +1,6 @@
+/**
+ * @defgroup pkg_esp32_sdk_libs  ESP32 SDK libraries for the ESP32 MCU support
+ * @ingroup  pkg_esp32_sdk
+ * @brief    Vendor SDK libraries for ESP32 MCU support by Espressif
+ * @see      https://github.com/espressif/esp32-wifi-lib
+ */