ESP IDF fixes (#927)

Various fixes and beautifications coordinated with @1c3t3a,
fixes 2 of the 3 all remaining issues from #892:
- enable to os_mmap executable memory
- fix os_malloc/os_realloc/os_free issues
- implement os_thread_get_stack_boundary
- add build scripts to include with esp-idf to use wamr as
  an ESP-IDF component
- update sample and document

product-mini/platforms/esp-idf/CMakeLists.txt

@@ -1,77 +1,12 @@
-# Copyright (C) 2019 Intel Corporation.  All rights reserved.
+# Copyright (C) 2019-21 Intel Corporation and others.  All rights reserved.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 # from ESP-IDF 4.0 examples/build_system/cmake/idf_as_lib
 cmake_minimum_required(VERSION 3.5)
-project(wamr_on_esp32c3)
 
-enable_language(ASM)
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 
-if (NOT CMAKE_BUILD_TYPE)
-  set(CMAKE_BUILD_TYPE Release)
-endif ()
+set (COMPONENTS ${IDF_TARGET} main freertos esptool_py wamr)
+list(APPEND EXTRA_COMPONENT_DIRS "$ENV{WAMR_PATH}/build-scripts/esp-idf")
 
-if("${IDF_TARGET}" STREQUAL "")
-    message(FATAL_ERROR "You need to set IDF_TARGET to your target string")
-endif()
-
-# Include for ESP-IDF build system functions
-include($ENV{IDF_PATH}/tools/cmake/idf.cmake)
-# Create idf::esp32c3 and idf::freertos static libraries
-idf_build_process(${IDF_TARGET}
-                # try and trim the build; additional components
-                # will be included as needed based on dependency tree
-                #
-                # although esptool_py does not generate static library,
-                # processing the component is needed for flashing related
-                # targets and file generation
-                COMPONENTS ${IDF_TARGET} freertos esptool_py
-                SDKCONFIG ${CMAKE_BINARY_DIR}/sdkconfig
-                BUILD_DIR ${CMAKE_BINARY_DIR})
-
-# Set WAMR's build options
-if("${IDF_TARGET}" STREQUAL "esp32c3")
-    set(WAMR_BUILD_TARGET "RISCV32")
-else()
-    set(WAMR_BUILD_TARGET "XTENSA")
-    add_compile_options(-DWAMR_BUILD_TARGET_XTENSA=1)
-endif()
-
-set(WAMR_BUILD_PLATFORM "esp-idf")
-
-if (NOT DEFINED WAMR_BUILD_INTERP)
-  set (WAMR_BUILD_INTERP 0)
-endif ()
-
-if (NOT DEFINED WAMR_BUILD_FAST_INTERP)
-  set (WAMR_BUILD_FAST_INTERP 0)
-endif ()
-
-if (NOT DEFINED WAMR_BUILD_AOT)
-  set (WAMR_BUILD_AOT 1)
-endif ()
-
-if (NOT DEFINED WAMR_BUILD_LIBC_BUILTIN)
-  set (WAMR_BUILD_LIBC_BUILTIN 1)
-endif ()
-
-if (NOT DEFINED WAMR_BUILD_APP_FRAMEWORK)
-  set (WAMR_BUILD_APP_FRAMEWORK 0)
-endif ()
-
-
-# Set the compile time variable so that the right binary is selected
-add_compile_options(-DWAMR_BUILD_INTERP=${WAMR_BUILD_INTERP})
-
-set(WAMR_ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../..)
-include(${WAMR_ROOT_DIR}/build-scripts/runtime_lib.cmake)
-
-# define WAMR as library and provide it the esp-idf srcs
-add_library(vmlib ${WAMR_RUNTIME_LIB_SOURCE})
-target_link_libraries(vmlib PUBLIC idf::pthread idf::${IDF_TARGET} idf::freertos)
-
-# Define the final executable
-set(elf_file ${CMAKE_PROJECT_NAME}.elf)
-add_executable(${elf_file} main.c test_wasm.h)
-target_link_libraries(${elf_file} idf::${IDF_TARGET} idf::freertos idf::spi_flash vmlib)
-idf_build_executable(${elf_file})
+project(wamr-simple)