Optimize samples build process and build 64 bit binaries by default (#90)

* Optimize samples build process

* Samples: build 64 bit version by default

core/shared-lib/include/config.h

@@ -98,7 +98,11 @@
 #define APP_HEAP_SIZE_MAX (1024 * 1024)
 
 /* Default wasm stack size of each app */
+#ifdef __x86_64__
+#define DEFAULT_WASM_STACK_SIZE (12 * 1024)
+#else
 #define DEFAULT_WASM_STACK_SIZE (8 * 1024)
+#endif
 
 /* Default/min/max stack size of each app thread */
 #ifndef __ZEPHYR__

samples/gui/README.md

@@ -11,19 +11,37 @@ The sample also provides the native Linux version of application without the run
 
 The number on top will plus one each second, and the number on the bottom will plus one when clicked.
 
+Configure 32 bit or 64 bit build
+==============
+On 64 bit operating system, there is an option to build 32 bit or 64 bit binaries. In file `./lvgl-native-ui-app/CMakeLists.txt` and/or `./wasm-runtime-wgl/linux-build/CMakeLists.txt` , modify the line:
+`set (BUILD_AS_64BIT_SUPPORT "YES")`
+ where `YES` means 64 bit build while `NO` means 32 bit build.
+
 Install required SDK and libraries
 ==============
-- 32 bit SDL(simple directmedia layer)
-Use apt-get</br>
-    `sudo apt-get install libsdl2-dev:i386`</br>
-Or download source from www.libsdl.org</br>
-    `./configure C_FLAGS=-m32 CXX_FLAGS=-m32 LD_FLAGS=-m32`</br>
-    `make`</br>
-    `sudo make install`</br>
+- 32 bit SDL(simple directmedia layer) (Note: only necessary when `BUILD_AS_64BIT_SUPPORT` is set to `NO`)
+Use apt-get:
+    `sudo apt-get install libsdl2-dev:i386`
+Or download source from www.libsdl.org:
+```
+./configure C_FLAGS=-m32 CXX_FLAGS=-m32 LD_FLAGS=-m32
+make
+sudo make install
+```
+- 64 bit SDL(simple directmedia layer) (Note: only necessary when `BUILD_AS_64BIT_SUPPORT` is set to `YES`)
+Use apt-get:
+    `sudo apt-get install libsdl2-dev`
+Or download source from www.libsdl.org:
+```
+./configure
+make
+sudo make install
+```
+
 - Install EMSDK
-<pre>
+```
     https://emscripten.org/docs/tools_reference/emsdk.html
-</pre>
+```
 
 Build and Run
 ==============

samples/gui/build.sh

@@ -18,6 +18,14 @@ if [ ! -d "tlsf" ]; then
     git clone https://github.com/mattconte/tlsf
 fi
 
+cd ${WAMR_DIR}/core/iwasm/lib/3rdparty
+if [ ! -d "lvgl" ]; then
+        git clone https://github.com/littlevgl/lvgl.git --branch v6.0.1
+fi
+if [ ! -d "lv_drivers" ]; then
+        git clone https://github.com/littlevgl/lv_drivers.git
+fi
+
 echo "##################### 1. build native-ui-app start#####################"
 cd $BUILD_DIR
 mkdir -p lvgl-native-ui-app

samples/gui/lvgl-native-ui-app/CMakeLists.txt

@@ -17,36 +17,32 @@ message ("lvgl_native_ui_app...")
 project (lvgl_native_ui_app)
 
 #################################################################
-#SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32 -g)
-
-set(lv_name lvgl)
-set(lv_drivers_name lv_drivers)
-set(LVGL_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/${lv_name})
-set(LVGL_DRIVER_DIR ${CMAKE_CURRENT_SOURCE_DIR}/${lv_drivers_name})
-
-if ((NOT EXISTS ${LVGL_SOURCE_DIR}) OR (NOT EXISTS ${LVGL_DRIVER_DIR}))
-        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt.in ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl/CMakeLists.txt)
-
-        execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
-                RESULT_VARIABLE result
-                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl )
-        if(result)
-                message(FATAL_ERROR "CMake step for lvgl failed: ${result}")
-        endif()
-        execute_process(COMMAND ${CMAKE_COMMAND} --build .
-                RESULT_VARIABLE result
-                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl )
-        if(result)
-                message(FATAL_ERROR "Build step for lvgl failed: ${result}")
-        endif()
-endif()
+
+# Currently build as 64-bit by default. Set to "NO" to build 32-bit binaries.
+set (BUILD_AS_64BIT_SUPPORT "YES")
+
+if (CMAKE_SIZEOF_VOID_P EQUAL 8)
+        if (${BUILD_AS_64BIT_SUPPORT} STREQUAL "YES")
+                # Add -fPIC flag if build as 64-bit
+                set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")
+                set (CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "${CMAKE_SHARED_LIBRARY_LINK_C_FLAGS} -fPIC")
+        else ()
+                add_definitions (-m32)
+                set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
+                set (CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
+        endif ()
+endif ()
+
+set(THIRDPARTY_DIR ../../../core/iwasm/lib/3rdparty)
+set(LVGL_SOURCE_DIR ${THIRDPARTY_DIR}/lvgl)
+set(LVGL_DRIVER_DIR ${THIRDPARTY_DIR}/lv_drivers)
 
 #################################
-set(CMAKE_C_STANDARD 11)#C11
-set(CMAKE_CXX_STANDARD 17)#C17
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 INCLUDE_DIRECTORIES(${PROJECT_SOURCE_DIR})
+INCLUDE_DIRECTORIES(${THIRDPARTY_DIR})
+
+add_definitions (-DLV_CONF_INCLUDE_SIMPLE)
 
 file(GLOB_RECURSE INCLUDES "${LVGL_DRIVER_DIR}/*.h" "${LVGL_SOURCE_DIR}/*.h"  "./*.h" )
 file(GLOB_RECURSE SOURCES  "${LVGL_DRIVER_DIR}/*.c" "${LVGL_SOURCE_DIR}/*.c" )

samples/gui/lvgl-native-ui-app/CMakeLists.txt.in

@@ -1,40 +0,0 @@
-# Copyright (C) 2019 Intel Corporation.  All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-cmake_minimum_required(VERSION 2.8.2)
-
-project(lvgl_download NONE)
-
-include(ExternalProject)
-ExternalProject_Add(${lv_name}
-    GIT_REPOSITORY https://github.com/littlevgl/lvgl.git
-    GIT_TAG        "v6.0"
-    BINARY_DIR     ""
-    SOURCE_DIR            "${CMAKE_CURRENT_SOURCE_DIR}/${lv_name}"
-    CONFIGURE_COMMAND     ""
-    BUILD_COMMAND         ""
-    INSTALL_COMMAND       ""
-    TEST_COMMAND          ""
-  )
-
-ExternalProject_Add(${lv_drivers_name}
-    GIT_REPOSITORY https://github.com/littlevgl/lv_drivers.git
-    GIT_TAG        ""
-    BINARY_DIR     ""
-    SOURCE_DIR            "${CMAKE_CURRENT_SOURCE_DIR}/${lv_drivers_name}"
-    CONFIGURE_COMMAND     ""
-    BUILD_COMMAND         ""
-    INSTALL_COMMAND       ""
-    TEST_COMMAND          ""
-  )

samples/gui/wasm-runtime-wgl/linux-build/CMakeLists.txt

@@ -7,27 +7,8 @@ set(WASM_DIR  ${REPO_ROOT_DIR}/core/iwasm)
 set(APP_MGR_DIR ${REPO_ROOT_DIR}/core/app-mgr)
 set(SHARED_DIR ${REPO_ROOT_DIR}/core/shared-lib)
 
-set (lv_drivers_name lv_drivers)
-set (lv_name lvgl)
-set (LV_DRIVERS_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../src/platform/linux/${lv_drivers_name})
-set (LVGL_DIR ${WASM_DIR}/lib/3rdparty/${lv_name})
-
-if ((NOT EXISTS ${LVGL_DIR}) OR (NOT EXISTS ${LV_DRIVERS_DIR}))
-        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt.in ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl_drivers/CMakeLists.txt)
-
-        execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
-                RESULT_VARIABLE result
-                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl_drivers )
-        if(result)
-                message(FATAL_ERROR "CMake step for lvgl drivers failed: ${result}")
-        endif()
-        execute_process(COMMAND ${CMAKE_COMMAND} --build .
-                RESULT_VARIABLE result
-                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl_drivers )
-        if(result)
-                message(FATAL_ERROR "Build step for lvgl drivers failed: ${result}")
-        endif()
-endif()
+set (LV_DRIVERS_DIR ${WASM_DIR}/lib/3rdparty/lv_drivers)
+set (LVGL_DIR ${WASM_DIR}/lib/3rdparty/lvgl)
 
 file(GLOB_RECURSE LV_DRIVERS_SOURCES "${LV_DRIVERS_DIR}/*.c" )
 
@@ -95,10 +76,12 @@ include (${SHARED_DIR}/coap/lib_coap.cmake)
 set (PROJECT_SRC_DIR ${CMAKE_CURRENT_LIST_DIR}/../src/platform/${TARGET_PLATFORM})
 
 include_directories(${SHARED_DIR}/include)
+include_directories(${PROJECT_SRC_DIR})
 
 add_definitions (-DWASM_ENABLE_BASE_LIB)
 add_definitions (-Dattr_container_malloc=bh_malloc)
 add_definitions (-Dattr_container_free=bh_free)
+add_definitions (-DLV_CONF_INCLUDE_SIMPLE)
 
 add_library (vmlib
              ${WASM_PLATFORM_LIB_SOURCE}

samples/gui/wasm-runtime-wgl/linux-build/CMakeLists.txt.in

@@ -1,41 +0,0 @@
-# Copyright (C) 2019 Intel Corporation.  All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-cmake_minimum_required(VERSION 2.8.2)
-
-project(lvgl_download NONE)
-
-include(ExternalProject)
-
-ExternalProject_Add(${lv_name}
-    GIT_REPOSITORY https://github.com/littlevgl/lvgl.git
-    GIT_TAG        ""
-    BINARY_DIR     ""
-    SOURCE_DIR            "${LVGL_DIR}"
-    CONFIGURE_COMMAND     ""
-    BUILD_COMMAND         ""
-    INSTALL_COMMAND       ""
-    TEST_COMMAND          ""
-  )
-
-ExternalProject_Add(${lv_drivers_name}
-    GIT_REPOSITORY https://github.com/littlevgl/lv_drivers.git
-    GIT_TAG        ""
-    BINARY_DIR     ""
-    SOURCE_DIR            "${LV_DRIVERS_DIR}"
-    CONFIGURE_COMMAND     ""
-    BUILD_COMMAND         ""
-    INSTALL_COMMAND       ""
-    TEST_COMMAND          ""
-  )

samples/littlevgl/README.md

@@ -21,19 +21,38 @@ The sample also provides the native Linux version of application without the run
 
 The number on top will plus one each second, and the number on the bottom will plus one when clicked.
 
+Configure 32 bit or 64 bit build
+==============
+On 64 bit operating system, there is an option to build 32 bit or 64 bit binaries. In file `./vgl-native-ui-app/CMakeLists.txt` and/or `./vgl-wasm-runtime/CMakeLists.txt` , modify the line:
+`set (BUILD_AS_64BIT_SUPPORT "YES")`
+ where `YES` means 64 bit build while `NO` means 32 bit build.
+
 Install required SDK and libraries
 ==============
-- 32 bit SDL(simple directmedia layer)
-Use apt-get</br>
-    `sudo apt-get install libsdl2-dev:i386`</br>
-Or download source from www.libsdl.org</br>
-    `./configure C_FLAGS=-m32 CXX_FLAGS=-m32 LD_FLAGS=-m32`</br>
-    `make`</br>
-    `sudo make install`</br>
+- 32 bit SDL(simple directmedia layer) (Note: only necessary when `BUILD_AS_64BIT_SUPPORT` is set to `NO`)
+Use apt-get:
+    `sudo apt-get install libsdl2-dev:i386`
+Or download source from www.libsdl.org:
+```
+./configure C_FLAGS=-m32 CXX_FLAGS=-m32 LD_FLAGS=-m32
+make
+sudo make install
+```
+- 64 bit SDL(simple directmedia layer) (Note: only necessary when `BUILD_AS_64BIT_SUPPORT` is set to `YES`)
+Use apt-get:
+    `sudo apt-get install libsdl2-dev`
+Or download source from www.libsdl.org:
+```
+./configure
+make
+sudo make install
+```
+
 - Install EMSDK
-<pre>
+```
     https://emscripten.org/docs/tools_reference/emsdk.html
-</pre>
+```
+
 
 Build and Run
 ==============

samples/littlevgl/build.sh

@@ -18,6 +18,12 @@ if [ ! -d "tlsf" ]; then
     git clone https://github.com/mattconte/tlsf
 fi
 
+cd ${WAMR_DIR}/core/iwasm/lib/3rdparty
+if [ ! -d "lvgl" ]; then
+        git clone https://github.com/littlevgl/lvgl.git --branch v6.0.1
+fi
+
+
 echo "##################### 1. build native-ui-app start#####################"
 cd $BUILD_DIR
 mkdir -p vgl-native-ui-app

samples/littlevgl/vgl-native-ui-app/CMakeLists.txt

@@ -17,7 +17,22 @@ message ("vgl_native_ui_app...")
 project (vgl_native_ui_app)
 
 
-SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32 -g -DLV_CONF_INCLUDE_SIMPLE -DPLATFORM_NATIVE_LINUX -DUSE_MONITOR -DUSE_MOUSE=1")
+SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DLV_CONF_INCLUDE_SIMPLE -DPLATFORM_NATIVE_LINUX -DUSE_MONITOR -DUSE_MOUSE=1")
+
+# Currently build as 64-bit by default. Set to "NO" to build 32-bit binaries.
+set (BUILD_AS_64BIT_SUPPORT "YES")
+
+if (CMAKE_SIZEOF_VOID_P EQUAL 8)
+        if (${BUILD_AS_64BIT_SUPPORT} STREQUAL "YES")
+                # Add -fPIC flag if build as 64-bit
+                set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")
+                set (CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "${CMAKE_SHARED_LIBRARY_LINK_C_FLAGS} -fPIC")
+        else ()
+                add_definitions (-m32)
+                set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
+                set (CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
+        endif ()
+endif ()
 
 set(lv_name lvgl)
 set(LVGL_SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/${lv_name})

samples/littlevgl/vgl-wasm-runtime/CMakeLists.txt

@@ -15,8 +15,8 @@ if (NOT ("$ENV{VALGRIND}" STREQUAL "YES"))
   add_definitions(-DNVALGRIND)
 endif ()
 
-# Currently build as 32-bit by default.
-set (BUILD_AS_64BIT_SUPPORT "NO")
+# Currently build as 64-bit by default.
+set (BUILD_AS_64BIT_SUPPORT "YES")
 
 if (CMAKE_SIZEOF_VOID_P EQUAL 8)
 if (${BUILD_AS_64BIT_SUPPORT} STREQUAL "YES")

samples/littlevgl/vgl-wasm-runtime/src/platform/linux/display_indev.c

@@ -186,12 +186,29 @@ void display_map(int32_t x1, int32_t y1, int32_t x2, int32_t y2,
 
 bool display_input_read(int32 data_p_offset)
 {
+    bool ret;
     wasm_module_inst_t module_inst = wasm_runtime_get_current_module_inst();
     if (!wasm_runtime_validate_app_addr(module_inst, data_p_offset, 1))
         return false;
-    lv_indev_data_t * data = wasm_runtime_addr_app_to_native(module_inst,
-            data_p_offset);
-    return mouse_read(data);
+
+    struct {
+        lv_point_t point;
+        int32 user_data_offset;
+        uint8 state;
+    } *data_app;
+
+    lv_indev_data_t data;
+
+    ret = mouse_read(&data);
+
+    data_app = wasm_runtime_addr_app_to_native(module_inst,
+                                               data_p_offset);
+
+    data_app->point = data.point;
+    data_app->user_data_offset = (int32_t)data.user_data;
+    data_app->state = data.state;
+
+    return ret;
 }
 
 void display_deinit(void)

samples/littlevgl/vgl-wasm-runtime/src/platform/linux/iwasm_main.c

@@ -343,7 +343,11 @@ static host_interface interface = { .send = uart_send, .destroy = uart_destroy }
 
 #endif
 
+#ifdef __x86_64__
+static char global_heap_buf[300 * 1024] = { 0 };
+#else
 static char global_heap_buf[270 * 1024] = { 0 };
+#endif
 
 static void showUsage()
 {

samples/simple/CMakeLists.txt

@@ -48,27 +48,8 @@ set(WASM_DIR  ${WAMR_ROOT_DIR}/core/iwasm)
 set(APP_MGR_DIR ${WAMR_ROOT_DIR}/core/app-mgr)
 set(SHARED_DIR ${WAMR_ROOT_DIR}/core/shared-lib)
 
-set (lv_drivers_name lv_drivers)
-set (lv_name lvgl)
-set (LV_DRIVERS_DIR ${CMAKE_CURRENT_SOURCE_DIR}/src/${lv_drivers_name})
-set (LVGL_DIR ${WASM_DIR}/lib/3rdparty/${lv_name})
-
-if ((NOT EXISTS ${LVGL_DIR}) OR (NOT EXISTS ${LV_DRIVERS_DIR}))
-        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt.in ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl_drivers/CMakeLists.txt)
-
-        execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
-                RESULT_VARIABLE result
-                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl_drivers )
-        if(result)
-                message(FATAL_ERROR "CMake step for lvgl drivers failed: ${result}")
-        endif()
-        execute_process(COMMAND ${CMAKE_COMMAND} --build .
-                RESULT_VARIABLE result
-                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl_drivers )
-        if(result)
-                message(FATAL_ERROR "Build step for lvgl drivers failed: ${result}")
-        endif()
-endif()
+set (LV_DRIVERS_DIR ${WASM_DIR}/lib/3rdparty/lv_drivers)
+set (LVGL_DIR ${WASM_DIR}/lib/3rdparty/lvgl)
 
 file(GLOB_RECURSE LV_DRIVERS_SOURCES "${LV_DRIVERS_DIR}/*.c" )
 
@@ -93,12 +74,14 @@ include (${SHARED_DIR}/coap/lib_coap.cmake)
 
 
 include_directories(${SHARED_DIR}/include)
+include_directories(${CMAKE_CURRENT_LIST_DIR}/src)
 
 #Note: uncomment below line to use UART mode
 #add_definitions (-DCONNECTION_UART)
 add_definitions (-DWASM_ENABLE_BASE_LIB)
 add_definitions (-Dattr_container_malloc=bh_malloc)
 add_definitions (-Dattr_container_free=bh_free)
+add_definitions (-DLV_CONF_INCLUDE_SIMPLE)
 
 add_library (vmlib
              ${WASM_PLATFORM_LIB_SOURCE}

samples/simple/CMakeLists.txt.in

@@ -1,41 +0,0 @@
-# Copyright (C) 2019 Intel Corporation.  All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-cmake_minimum_required(VERSION 2.8.2)
-
-project(lvgl_download NONE)
-
-include(ExternalProject)
-
-ExternalProject_Add(${lv_name}
-    GIT_REPOSITORY https://github.com/littlevgl/lvgl.git
-    GIT_TAG        ""
-    BINARY_DIR     ""
-    SOURCE_DIR            "${LVGL_DIR}"
-    CONFIGURE_COMMAND     ""
-    BUILD_COMMAND         ""
-    INSTALL_COMMAND       ""
-    TEST_COMMAND          ""
-  )
-
-ExternalProject_Add(${lv_drivers_name}
-    GIT_REPOSITORY https://github.com/littlevgl/lv_drivers.git
-    GIT_TAG        ""
-    BINARY_DIR     ""
-    SOURCE_DIR            "${LV_DRIVERS_DIR}"
-    CONFIGURE_COMMAND     ""
-    BUILD_COMMAND         ""
-    INSTALL_COMMAND       ""
-    TEST_COMMAND          ""
-  )

samples/simple/README.md

@@ -64,19 +64,37 @@ The `host_init_func` is called when the application manager starts up. And `host
 - wasm-apps<br/>
   Source files of sample wasm applications.
 
+Configure 32 bit or 64 bit build
+==============
+On 64 bit operating system, there is an option to build 32 bit or 64 bit binaries. In file `CMakeLists.txt`, modify the line:
+`set (BUILD_AS_64BIT_SUPPORT "YES")`
+ where `YES` means 64 bit build while `NO` means 32 bit build.
+
 Install required SDK and libraries
 ==============
-- 32 bit SDL(simple directmedia layer)
-Use apt-get</br>
-    `sudo apt-get install libsdl2-dev:i386`</br>
-Or download source from www.libsdl.org</br>
-    `./configure C_FLAGS=-m32 CXX_FLAGS=-m32 LD_FLAGS=-m32`</br>
-    `make`</br>
-    `sudo make install`</br>
+- 32 bit SDL(simple directmedia layer) (Note: only necessary when `BUILD_AS_64BIT_SUPPORT` is set to `NO`)
+Use apt-get:
+    `sudo apt-get install libsdl2-dev:i386`
+Or download source from www.libsdl.org:
+```
+./configure C_FLAGS=-m32 CXX_FLAGS=-m32 LD_FLAGS=-m32
+make
+sudo make install
+```
+- 64 bit SDL(simple directmedia layer) (Note: only necessary when `BUILD_AS_64BIT_SUPPORT` is set to `YES`)
+Use apt-get:
+    `sudo apt-get install libsdl2-dev`
+Or download source from www.libsdl.org:
+```
+./configure
+make
+sudo make install
+```
+
 - Install EMSDK
-<pre>
+```
     https://emscripten.org/docs/tools_reference/emsdk.html
-</pre>
+```
 
 Build all binaries
 ==============

samples/simple/build.sh

@@ -20,6 +20,14 @@ if [ ! -d "tlsf" ]; then
     git clone https://github.com/mattconte/tlsf
 fi
 
+cd ${WAMR_DIR}/core/iwasm/lib/3rdparty
+if [ ! -d "lvgl" ]; then
+    git clone https://github.com/littlevgl/lvgl.git --branch v6.0.1
+fi
+if [ ! -d "lv_drivers" ]; then
+        git clone https://github.com/littlevgl/lv_drivers.git
+fi
+
 echo "#####################build simple project"
 cd ${CURR_DIR}
 mkdir -p cmake_build