subsys: net: lib: Add OpenThread platform

OpenThread requires platform definition with standarized API
so we have to add wrappers to make it compatible with Zephyr.
OpenThread is based on autoconf, this requires
more specific CMakeLists.txt which allows to clone specific
commit or point to local copy of openthread.

Signed-off-by: Kamil Sroka <[email protected]>

Author: KaSroka

subsys/net/lib/CMakeLists.txt

@@ -12,3 +12,4 @@ if(CONFIG_HTTP_PARSER_URL
   add_subdirectory(http)
 endif()
 
+add_subdirectory_ifdef(CONFIG_OPENTHREAD_PLAT openthread)

subsys/net/lib/openthread/CMakeLists.txt

@@ -0,0 +1,252 @@
+# Invoke OpenThread's external autoconf-based build system.
+include(ExternalProject)
+
+set(ep_base ${PROJECT_BINARY_DIR}/ext_proj)
+set_property(DIRECTORY PROPERTY "EP_BASE" ${ep_base})
+
+# Construct a list of commands to give to ExternalProject_Add()
+#
+# See https://cmake.org/cmake/help/latest/module/ExternalProject.html
+# for documentation on ExternalProject_Add
+set(cmd "")
+
+set(ot_name ot)
+list(APPEND cmd
+  ${ot_name}
+  )
+
+set(ot_STAMP_DIR   ${ep_base}/Stamp/${ot_name})
+set(ot_INSTALL_DIR ${ep_base}/Install/${ot_name})
+
+#--Download step--------------
+if(NOT EXTERNAL_PROJECT_PATH_OPENTHREAD)
+  # TODO: Point to a Zephyr fork
+  # Nov. 7
+  set_ifndef(ot_GIT_REPOSITORY "https://github.com/openthread/openthread.git")
+  set_ifndef(ot_GIT_TAG a89eb887488dcbab7f5e9237e2bbcaad38140690)
+  set_ifndef(ot_GIT_PROGRESS 1)
+
+  list(APPEND cmd
+    GIT_REPOSITORY ${ot_GIT_REPOSITORY}
+    GIT_TAG        ${ot_GIT_TAG}
+    GIT_PROGRESS   ${ot_GIT_PROGRESS}
+    )
+endif()
+
+#--Update/Patch step-------------
+
+# An update step is not necessary because we are using a commit hash
+# as a tag, and the code behind a hash cannot change.
+
+# UPDATE_DISCONNECTED should be used when updates aren't needed, but
+# for some reason we were not able to get this to work, so we use a
+# dummy step to fake updating. This ensures that the git repo is not
+# downloaded on every 'make' invocation.
+list(APPEND cmd
+  UPDATE_COMMAND
+  ${CMAKE_COMMAND} -E touch ${ot_STAMP_DIR}/${ot_name}-update
+  )
+
+#--Configure step-------------
+if(EXTERNAL_PROJECT_PATH_OPENTHREAD)
+  set(ot_SOURCE_DIR ${EXTERNAL_PROJECT_PATH_OPENTHREAD})
+
+  list(APPEND cmd
+    SOURCE_DIR ${ot_SOURCE_DIR}
+    )
+
+else()
+  set(ot_SOURCE_DIR ${ep_base}/Source/${ot_name}) # TODO: Download dir?
+
+  # "If SOURCE_DIR is explicitly set to an existing directory the
+  # project will be built from it. Otherwise a download step must be
+  # specified using one of the DOWNLOAD_COMMAND, CVS_*, SVN_*, or URL
+  # options." -- CMake docs
+endif()
+
+# TODO: Can we omit this, does OpenThread need to use install?
+# TODO: Move this to host-tools?
+find_program(INSTALL install)
+
+# It looks like OpenThread requires a *nix system to build for
+# embedded.
+#
+# https://github.com/openthread/openthread/blob/master/examples/drivers/windows/README.md
+
+# TODO: Use different includes for C and CXX
+zephyr_get_include_directories_for_lang_as_string(       C includes)
+zephyr_get_system_include_directories_for_lang_as_string(C system_includes)
+zephyr_get_compile_definitions_for_lang_as_string(       C definitions)
+
+zephyr_get_compile_options_for_lang_as_string(C   c_options)
+zephyr_get_compile_options_for_lang_as_string(CXX cxx_options)
+
+# TODO: What happens if a CFLAG is added after this build script has
+# been run?
+
+# TODO: Does OpenThread need all flags, or just some? Should we
+# whitelist, or blacklist flags?
+
+
+# TODO: What is all this? $(dir $(realpath $(firstword $(MAKEFILE_LIST))))
+
+set(exec_prefix zephyr)
+
+set(commoncflags "-DOPENTHREAD_CONFIG_LOG_LEVEL=${CONFIG_OPENTHREAD_LOG_LEVEL}")
+set(commoncflags "${commoncflags} -DOPENTHREAD_PROJECT_CORE_CONFIG_FILE=\\\"openthread-core-zephyr-config.h\\\"")
+set(commoncflags "${commoncflags} -I${CMAKE_CURRENT_LIST_DIR}/platform")
+
+set(configure_flags
+  "INSTALL=${INSTALL} -p"
+  "CPP=${CMAKE_C_COMPILER} -E"                 # TODO: Find CPP in toolchain-gcc.cmake and use that instead?
+  "CC=${CMAKE_C_COMPILER}"
+  "CXX=${CMAKE_CXX_COMPILER}"
+  OBJC=""                      # TODO: Omit this?
+  "OBJCXX=${OBJCXX}"           # TODO: Omit this?
+  "AR=${CMAKE_AR}"
+  "RANLIB=${CMAKE_RANLILB}"
+  "NM=${CROSS_COMPILE}nm"      # TODO: Find NM in toolchain-gcc.cmake and use that instead?
+  "STRIP=${CMAKE_STRIP}"
+  "CPPFLAGS=${definitions} ${commoncflags} ${includes} ${system_includes}"
+  "CFLAGS=${c_options}     ${commoncflags} ${includes} ${system_includes}"
+  "CXXFLAGS=${cxx_options} ${commoncflags} ${includes} ${system_includes}" # TODO: Do we need includes here?
+  LDFLAGS="" # TODO: What does a networking stack need to use the linker for?
+
+  --host=arm-none-eabi
+  --prefix=/
+  --exec-prefix=/${exec_prefix}
+  --target=arm-none-eabi # TODO: Is Kconfig expressing that OT is ARM-only?
+  --enable-no-executables-hack
+  --disable-docs
+  --with-platform-info=zephyr
+)
+
+# TODO: Simplify
+set(ZEPHYR_MBEDTLS_CPPFLAGS "${ZEPHYR_MBEDTLS_CPPFLAGS} ")
+set(ZEPHYR_MBEDTLS_CPPFLAGS "-DMBEDTLS_CONFIG_FILE='\"mbedtls-config.h\"'")
+set(ZEPHYR_MBEDTLS_CPPFLAGS "${ZEPHYR_MBEDTLS_CPPFLAGS} -DMBEDTLS_USER_CONFIG_FILE='\"${CMAKE_CURRENT_SOURCE_DIR}/zephyr-mbedtls-config.h\"'")
+set(ZEPHYR_MBEDTLS_CPPFLAGS "${ZEPHYR_MBEDTLS_CPPFLAGS} -I${ot_SOURCE_DIR}/third_party/mbedtls")
+set(ZEPHYR_MBEDTLS_CPPFLAGS "${ZEPHYR_MBEDTLS_CPPFLAGS} -I${ot_SOURCE_DIR}/third_party/mbedtls/repo.patched/include")
+set(ZEPHYR_MBEDTLS_CPPFLAGS "${ZEPHYR_MBEDTLS_CPPFLAGS} -I${ot_SOURCE_DIR}/third_party/mbedtls/repo.patched/include/mbedtls")
+
+list(APPEND configure_flags
+  "MBEDTLS_CPPFLAGS=${ZEPHYR_MBEDTLS_CPPFLAGS}"
+  )
+
+if(CONFIG_OPENTHREAD_COMMISSIONER)
+  list(APPEND configure_flags
+    --enable-commissioner
+    )
+endif()
+
+if(CONFIG_OPENTHREAD_JAM_DETECTION)
+  list(APPEND configure_flags
+    --enable-jam-detection
+    )
+endif()
+
+if(CONFIG_OPENTHREAD_JOINER)
+  list(APPEND configure_flags
+    --enable-joiner
+    )
+endif()
+
+if(CONFIG_OPENTHREAD_SHELL)
+  list(APPEND configure_flags
+    --enable-cli-app=all
+    )
+endif()
+
+if(CONFIG_OPENTHREAD_DIAG)
+  list(APPEND configure_flags
+    --enable-diag
+    )
+endif()
+
+list(APPEND cmd
+  CONFIGURE_COMMAND ./configure ${configure_flags}
+)
+
+#--Build step-----------------
+
+# Invoke OpenThread's build system from the root of it's source
+# directory
+# TODO: Support out-of-source builds
+set(ot_BINARY_DIR  ${ot_SOURCE_DIR})
+list(APPEND cmd
+  BINARY_DIR  ${ot_BINARY_DIR}
+  INSTALL_DIR ${ot_INSTALL_DIR}
+  )
+
+set(make_flags
+  -j99 # TODO: Why 99?
+  --no-print-directory
+  )
+
+list(APPEND cmd
+  BUILD_COMMAND   make ${make_flags}                           all
+  INSTALL_COMMAND make ${make_flags} DESTDIR=${ot_INSTALL_DIR} install
+  )
+
+# TODO: Find out how to make this work.
+set(ot_include_dir ${ot_SOURCE_DIR}/include)
+
+# TODO: Is this only needed by alarm.c?
+zephyr_system_include_directories(${ot_include_dir})
+
+# TODO: Why doesn't app get this path from the above function call?
+target_include_directories(app SYSTEM PRIVATE ${ot_include_dir})
+
+#set_target_properties(ot_lib PROPERTIES INTERFACE_INCLUDE_DIRECTORIES ${ot_include_dir})
+zephyr_include_directories(${ot_include_dir})
+
+# Determine which libs should be linked in
+set(ot_libs
+  openthread-platform-utils
+  mbedcrypto
+  )
+if(CONFIG_OPENTHREAD_FTD)
+  list(APPEND ot_libs openthread-ftd)
+  set(cli_lib         openthread-cli-ftd)
+elseif(CONFIG_OPENTHREAD_MTD)
+  list(APPEND ot_libs openthread-mtd)
+  set(cli_lib         openthread-cli-ftd)
+endif()
+
+if(CONFIG_OPENTHREAD_SHELL)
+  list(APPEND ot_libs ${cli_lib})
+endif()
+
+foreach(ot_lib ${ot_libs})
+  set(build_byproducts ${build_byproducts} ${ot_INSTALL_DIR}/${exec_prefix}/lib/lib${ot_lib}.a)
+endforeach()
+
+list(APPEND cmd
+  BUILD_BYPRODUCTS ${build_byproducts}
+  )
+
+ExternalProject_Add(${cmd})
+
+ExternalProject_Add_Step(
+  ${ot_name} bootstrap # Names of project and custom step
+  COMMAND ./bootstrap     # Command line invoked by this step
+  COMMENT "bootstrapping..." # Text printed when step executes
+  DEPENDEES download        # Steps on which this step depends
+  DEPENDERS configure     # Steps that depend on this step
+  WORKING_DIRECTORY ${ot_SOURCE_DIR}
+  )
+
+# Create wrapper CMake libraries
+foreach(ot_lib ${ot_libs})
+  add_library(${ot_lib} STATIC IMPORTED GLOBAL)
+  add_dependencies(   # TODO: Necessary?
+    ${ot_lib}
+    ${ot_name}
+    )
+  set_target_properties(${ot_lib} PROPERTIES IMPORTED_LOCATION
+    ${ot_INSTALL_DIR}/${exec_prefix}/lib/lib${ot_lib}.a
+    )
+  zephyr_append_cmake_library(${ot_lib})
+endforeach()
+
+add_subdirectory(platform)

subsys/net/lib/openthread/platform/CMakeLists.txt

@@ -0,0 +1,17 @@
+zephyr_library_named(openthread_platform)
+zephyr_library_sources(
+  alarm.c
+  flash.c
+  logging.c
+  misc.c
+  platform.c
+  radio.c
+  random.c
+  spi.c
+  )
+
+zephyr_library_sources_ifdef(CONFIG_OPENTHREAD_SHELL shell.c)
+
+# The source files here use header files from the OpenThread project
+# target_link_libraries(app ot_lib) # Better?
+add_dependencies(openthread_platform ot)

subsys/net/lib/openthread/platform/alarm.c

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2018 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include <openthread/platform/alarm-milli.h>
+#include <openthread/platform/platform.h>
+
+#define SYS_LOG_DOMAIN "openthread-plat"
+#define SYS_LOG_LEVEL SYS_LOG_LEVEL_DEBUG
+#include <logging/sys_log.h>
+#include <stdio.h>
+
+#include "platform-zephyr.h"
+
+static bool timer_fired;
+
+static void ot_timer_fired(struct k_timer *timer)
+{
+	ARG_UNUSED(timer);
+
+	timer_fired = true;
+	PlatformEventSignalPending();
+}
+
+K_TIMER_DEFINE(ot_timer, ot_timer_fired, NULL);
+
+void platformAlarmInit(void)
+{
+	/* Intentionally empty */
+}
+
+uint32_t otPlatAlarmMilliGetNow(void)
+{
+	return k_uptime_get_32();
+}
+
+void otPlatAlarmMilliStartAt(otInstance *aInstance, uint32_t t0, uint32_t dt)
+{
+	ARG_UNUSED(aInstance);
+
+	s64_t reftime = (s64_t)t0 + (s64_t)dt;
+	s64_t delta = -k_uptime_delta(&reftime);
+
+	if (delta > 0) {
+		k_timer_start(&ot_timer, K_MSEC(delta), 0);
+	} else {
+		ot_timer_fired(NULL);
+	}
+}
+
+void otPlatAlarmMilliStop(otInstance *aInstance)
+{
+	ARG_UNUSED(aInstance);
+
+	k_timer_stop(&ot_timer);
+}
+
+
+void platformAlarmProcess(otInstance *aInstance)
+{
+	if (timer_fired) {
+		timer_fired = false;
+		otPlatAlarmMilliFired(aInstance);
+	}
+}