Merge remote-tracking branch 'upstream/master' into pr/1702

9 files changed, 178 insertions, 169 deletions

diff --git a/examples/device/cdc_msc_freertos/CMakeLists.txt b/examples/device/cdc_msc_freertos/CMakeLists.txt
index 639dde99a..33c7a1ec0 100644
--- a/examples/device/cdc_msc_freertos/CMakeLists.txt
+++ b/examples/device/cdc_msc_freertos/CMakeLists.txt
@@ -1,22 +1,35 @@
-cmake_minimum_required(VERSION 3.5)
-
-# TOP is absolute path to root directory of TinyUSB git repo
-# needed for esp32sx build. TOOD could be removed later on
-set(TOP "../../..")
-get_filename_component(TOP "${TOP}" REALPATH)
+cmake_minimum_required(VERSION 3.17)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
 
 # gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
 family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
 
-project(${PROJECT})
+project(${PROJECT} C CXX ASM)
 
 # Checks this example is valid for the family and initializes the project
 family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
 
-# Check for -DFAMILY=
-if(FAMILY MATCHES "^esp32s[2-3]")
-else()
-  message(FATAL_ERROR "Invalid FAMILY specified: ${FAMILY}")
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
 endif()
+
+add_executable(${PROJECT})
+
+# Example source
+target_sources(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/freertos_hook.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/msc_disk.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
+
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
+
+# Configure compilation flags and libraries for the example with FreeRTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT} freertos)
diff --git a/examples/device/cdc_msc_freertos/Makefile b/examples/device/cdc_msc_freertos/Makefile
index 3352dd37d..13f336f99 100644
--- a/examples/device/cdc_msc_freertos/Makefile
+++ b/examples/device/cdc_msc_freertos/Makefile
@@ -1,17 +1,15 @@
-DEPS_SUBMODULES += lib/FreeRTOS-Kernel
-
-include ../../../tools/top.mk
-include ../../make.mk
+include ../../build_system/make/make.mk
 
 FREERTOS_SRC = lib/FreeRTOS-Kernel
+FREERTOS_PORTABLE_PATH= $(FREERTOS_SRC)/portable/$(if $(USE_IAR),IAR,GCC)
 
 INC += \
 	src \
 	src/FreeRTOSConfig \
 	$(TOP)/hw \
 	$(TOP)/$(FREERTOS_SRC)/include \
-	$(TOP)/$(FREERTOS_SRC)/portable/GCC/$(FREERTOS_PORT)
-	
+	$(TOP)/$(FREERTOS_PORTABLE_SRC) \
+
 # Example source
 EXAMPLE_SOURCE = \
 	src/freertos_hook.c \
@@ -27,12 +25,22 @@ SRC_C += \
 	$(FREERTOS_SRC)/queue.c \
 	$(FREERTOS_SRC)/tasks.c \
 	$(FREERTOS_SRC)/timers.c \
-	$(subst ../../../,,$(wildcard ../../../$(FREERTOS_SRC)/portable/GCC/$(FREERTOS_PORT)/*.c))
+	$(subst $(TOP)/,,$(wildcard $(TOP)/$(FREERTOS_PORTABLE_SRC)/*.c))
+
+SRC_S += \
+	$(subst $(TOP)/,,$(wildcard $(TOP)/$(FREERTOS_PORTABLE_SRC)/*.s))
+
+# include heap manage if configSUPPORT_DYNAMIC_ALLOCATION = 1
+# SRC_C += $(FREERTOS_SRC)/portable/MemMang/heap_1.c
+# CFLAGS += -Wno-error=sign-compare
+
+# Suppress FreeRTOSConfig.h warnings
+CFLAGS_GCC += -Wno-error=redundant-decls
 
-# Suppress FreeRTOS warnings
-CFLAGS += -Wno-error=cast-qual -Wno-error=redundant-decls
+# Suppress FreeRTOS source warnings
+CFLAGS_GCC += -Wno-error=cast-qual
 
 # FreeRTOS (lto + Os) linker issue
-LDFLAGS += -Wl,--undefined=vTaskSwitchContext
+LDFLAGS_GCC += -Wl,--undefined=vTaskSwitchContext
 
-include ../../rules.mk
+include ../../build_system/make/rules.mk
diff --git a/examples/device/cdc_msc_freertos/skip.txt b/examples/device/cdc_msc_freertos/skip.txt
index 1ee51a9d4..a6f96b288 100644
--- a/examples/device/cdc_msc_freertos/skip.txt
+++ b/examples/device/cdc_msc_freertos/skip.txt
@@ -1,3 +1,4 @@
+mcu:CH32V307
 mcu:CXD56
 mcu:F1C100S
 mcu:GD32VF103
@@ -7,5 +8,6 @@ mcu:RP2040
 mcu:SAMD11
 mcu:SAMX7X
 mcu:VALENTYUSB_EPTRI
+mcu:RAXXX
 family:broadcom_32bit
-family:broadcom_64bit
\ No newline at end of file
+family:broadcom_64bit
diff --git a/examples/device/cdc_msc_freertos/src/CMakeLists.txt b/examples/device/cdc_msc_freertos/src/CMakeLists.txt
index 9216e2b49..fee264363 100644
--- a/examples/device/cdc_msc_freertos/src/CMakeLists.txt
+++ b/examples/device/cdc_msc_freertos/src/CMakeLists.txt
@@ -1,35 +1,4 @@
+# This file is for ESP-IDF only
 idf_component_register(SRCS "main.c" "usb_descriptors.c" "msc_disk.c"
                     INCLUDE_DIRS "."
-                    REQUIRES freertos soc)
-
-file(TO_NATIVE_PATH "${TOP}/hw/bsp/${FAMILY}/boards/${BOARD}/board.cmake" board_cmake)
-
-if(EXISTS ${board_cmake})
-    include(${board_cmake})
-endif()
-
-target_include_directories(${COMPONENT_TARGET} PUBLIC
-  "${TOP}/hw"
-  "${TOP}/src"
-)
-
-target_compile_definitions(${COMPONENT_TARGET} PUBLIC
-  ESP_PLATFORM
-)
-
-target_sources(${COMPONENT_TARGET} PUBLIC
-  "${TOP}/src/tusb.c"
-  "${TOP}/src/common/tusb_fifo.c"
-  "${TOP}/src/device/usbd.c"
-  "${TOP}/src/device/usbd_control.c"
-  "${TOP}/src/class/cdc/cdc_device.c"
-  "${TOP}/src/class/dfu/dfu_rt_device.c"
-  "${TOP}/src/class/hid/hid_device.c"
-  "${TOP}/src/class/midi/midi_device.c"
-  "${TOP}/src/class/msc/msc_device.c"
-  "${TOP}/src/class/net/ecm_rndis_device.c"
-  "${TOP}/src/class/net/ncm_device.c"
-  "${TOP}/src/class/usbtmc/usbtmc_device.c"
-  "${TOP}/src/class/vendor/vendor_device.c"
-  "${TOP}/src/portable/synopsys/dwc2/dcd_dwc2.c"
-)
+                    REQUIRES boards tinyusb_src)
diff --git a/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h b/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
index 6a3630dbc..6cc7a6577 100644
--- a/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
+++ b/examples/device/cdc_msc_freertos/src/FreeRTOSConfig/FreeRTOSConfig.h
@@ -42,6 +42,9 @@
  * See http://www.freertos.org/a00110.html.
  *----------------------------------------------------------*/
 
+// skip if included from IAR assembler
+#ifndef __IASMARM__
+
 // Include MCU header
 #include "bsp/board_mcu.h"
 
@@ -57,6 +60,8 @@
   extern uint32_t SystemCoreClock;
 #endif
 
+#endif
+
 /* Cortex M23/M33 port configuration. */
 #define configENABLE_MPU								        0
 #define configENABLE_FPU								        1
@@ -69,14 +74,14 @@
 #define configTICK_RATE_HZ                      ( 1000 )
 #define configMAX_PRIORITIES                    ( 5 )
 #define configMINIMAL_STACK_SIZE                ( 128 )
-#define configTOTAL_HEAP_SIZE                   ( 0*1024 ) // dynamic is not used
+#define configTOTAL_HEAP_SIZE                   ( configSUPPORT_DYNAMIC_ALLOCATION*4*1024 )
 #define configMAX_TASK_NAME_LEN                 16
 #define configUSE_16_BIT_TICKS                  0
 #define configIDLE_SHOULD_YIELD                 1
 #define configUSE_MUTEXES                       1
 #define configUSE_RECURSIVE_MUTEXES             1
 #define configUSE_COUNTING_SEMAPHORES           1
-#define configQUEUE_REGISTRY_SIZE               2
+#define configQUEUE_REGISTRY_SIZE               4
 #define configUSE_QUEUE_SETS                    0
 #define configUSE_TIME_SLICING                  0
 #define configUSE_NEWLIB_REENTRANT              0
@@ -91,6 +96,7 @@
 #define configUSE_TICK_HOOK                    0
 #define configUSE_MALLOC_FAILED_HOOK           0 // cause nested extern warning
 #define configCHECK_FOR_STACK_OVERFLOW         2
+#define configCHECK_HANDLER_INSTALLATION       0
 
 /* Run time and task stats gathering related definitions. */
 #define configGENERATE_RUN_TIME_STATS          0
@@ -125,29 +131,12 @@
 #define INCLUDE_xEventGroupSetBitFromISR       0
 #define INCLUDE_xTimerPendFunctionCall         0
 
-/* Define to trap errors during development. */
-// Halt CPU (breakpoint) when hitting error, only apply for Cortex M3, M4, M7
-#if defined(__ARM_ARCH_7M__) || defined (__ARM_ARCH_7EM__)
-  #define configASSERT(_exp) \
-    do {\
-      if ( !(_exp) ) { \
-        volatile uint32_t* ARM_CM_DHCSR =  ((volatile uint32_t*) 0xE000EDF0UL); /* Cortex M CoreDebug->DHCSR */ \
-        if ( (*ARM_CM_DHCSR) & 1UL ) {  /* Only halt mcu if debugger is attached */ \
-          taskDISABLE_INTERRUPTS(); \
-           __asm("BKPT #0\n"); \
-        }\
-      }\
-    } while(0)
-#else
-  #define configASSERT( x )
-#endif
-
 #ifdef __RX__
 /* Renesas RX series */
-#define vSoftwareInterruptISR					INT_Excep_ICU_SWINT
-#define vTickISR								INT_Excep_CMT0_CMI0
-#define configPERIPHERAL_CLOCK_HZ				(configCPU_CLOCK_HZ/2)
-#define configKERNEL_INTERRUPT_PRIORITY			1
+#define vSoftwareInterruptISR					        INT_Excep_ICU_SWINT
+#define vTickISR								              INT_Excep_CMT0_CMI0
+#define configPERIPHERAL_CLOCK_HZ				      (configCPU_CLOCK_HZ/2)
+#define configKERNEL_INTERRUPT_PRIORITY			  1
 #define configMAX_SYSCALL_INTERRUPT_PRIORITY	4
 
 #else
@@ -163,9 +152,18 @@
 #if defined(__NVIC_PRIO_BITS)
   // For Cortex-M specific: __NVIC_PRIO_BITS is defined in core_cmx.h
 	#define configPRIO_BITS       __NVIC_PRIO_BITS
+
 #elif defined(__ECLIC_INTCTLBITS)
   // RISC-V Bumblebee core from nuclei
   #define configPRIO_BITS       __ECLIC_INTCTLBITS
+
+#elif defined(__IASMARM__)
+  // FIXME: IAR Assembler cannot include mcu header directly to get __NVIC_PRIO_BITS.
+  // Therefore we will hard coded it to minimum value of 2 to get pass ci build.
+  // IAR user must update this to correct value of the target MCU
+  #message "configPRIO_BITS is hard coded to 2 to pass IAR build only. User should update it per MCU"
+  #define configPRIO_BITS       2
+
 #else
   #error "FreeRTOS configPRIO_BITS to be defined"
 #endif
diff --git a/examples/device/cdc_msc_freertos/src/main.c b/examples/device/cdc_msc_freertos/src/main.c
index 755220c13..e94e8eaec 100644
--- a/examples/device/cdc_msc_freertos/src/main.c
+++ b/examples/device/cdc_msc_freertos/src/main.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
@@ -41,6 +41,7 @@
 
   #define USBD_STACK_SIZE     4096
 #else
+
   #include "FreeRTOS.h"
   #include "semphr.h"
   #include "queue.h"
@@ -51,8 +52,11 @@
   #define USBD_STACK_SIZE    (3*configMINIMAL_STACK_SIZE/2) * (CFG_TUSB_DEBUG ? 2 : 1)
 #endif
 
+#define CDC_STACK_SIZE      configMINIMAL_STACK_SIZE
+#define BLINKY_STACK_SIZE   configMINIMAL_STACK_SIZE
+
 //--------------------------------------------------------------------+
-// MACRO CONSTANT TYPEDEF PROTYPES
+// MACRO CONSTANT TYPEDEF PROTOTYPES
 //--------------------------------------------------------------------+
 
 /* Blink pattern
@@ -60,47 +64,51 @@
  * - 1000 ms : device mounted
  * - 2500 ms : device is suspended
  */
-enum  {
+enum {
   BLINK_NOT_MOUNTED = 250,
   BLINK_MOUNTED = 1000,
   BLINK_SUSPENDED = 2500,
 };
 
-// static timer
-StaticTimer_t blinky_tmdef;
-TimerHandle_t blinky_tm;
-
 // static task
+#if configSUPPORT_STATIC_ALLOCATION
+StackType_t blinky_stack[BLINKY_STACK_SIZE];
+StaticTask_t blinky_taskdef;
+
 StackType_t  usb_device_stack[USBD_STACK_SIZE];
 StaticTask_t usb_device_taskdef;
 
-// static task for cdc
-#define CDC_STACK_SZIE      configMINIMAL_STACK_SIZE
-StackType_t  cdc_stack[CDC_STACK_SZIE];
+StackType_t  cdc_stack[CDC_STACK_SIZE];
 StaticTask_t cdc_taskdef;
+#endif
 
+static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
 
-void led_blinky_cb(TimerHandle_t xTimer);
-void usb_device_task(void* param);
-void cdc_task(void* params);
+static void usb_device_task(void *param);
+void led_blinking_task(void* param);
+void cdc_task(void *params);
 
 //--------------------------------------------------------------------+
 // Main
 //--------------------------------------------------------------------+
 
-int main(void)
-{
+int main(void) {
   board_init();
 
-  // soft timer for blinky
-  blinky_tm = xTimerCreateStatic(NULL, pdMS_TO_TICKS(BLINK_NOT_MOUNTED), true, NULL, led_blinky_cb, &blinky_tmdef);
-  xTimerStart(blinky_tm, 0);
+#if configSUPPORT_STATIC_ALLOCATION
+  // blinky task
+  xTaskCreateStatic(led_blinking_task, "blinky", BLINKY_STACK_SIZE, NULL, 1, blinky_stack, &blinky_taskdef);
 
   // Create a task for tinyusb device stack
-  (void) xTaskCreateStatic( usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);
+  xTaskCreateStatic(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);
 
   // Create CDC task
-  (void) xTaskCreateStatic( cdc_task, "cdc", CDC_STACK_SZIE, NULL, configMAX_PRIORITIES-2, cdc_stack, &cdc_taskdef);
+  xTaskCreateStatic(cdc_task, "cdc", CDC_STACK_SIZE, NULL, configMAX_PRIORITIES - 2, cdc_stack, &cdc_taskdef);
+#else
+  xTaskCreate(led_blinking_task, "blinky", BLINKY_STACK_SIZE, NULL, 1, NULL);
+  xTaskCreate(usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, NULL);
+  xTaskCreate(cdc_task, "cdc", CDC_STACK_SZIE, NULL, configMAX_PRIORITIES - 2, NULL);
+#endif
 
   // skip starting scheduler (and return) for ESP32-S2 or ESP32-S3
 #if !TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
@@ -111,16 +119,14 @@ int main(void)
 }
 
 #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
-void app_main(void)
-{
+void app_main(void) {
   main();
 }
 #endif
 
 // USB Device Driver task
 // This top level thread process all usb events and invoke callbacks
-void usb_device_task(void* param)
-{
+static void usb_device_task(void *param) {
   (void) param;
 
   // init device stack on configured roothub port
@@ -128,9 +134,12 @@ void usb_device_task(void* param)
   // Otherwise it could cause kernel issue since USB IRQ handler does use RTOS queue API.
   tud_init(BOARD_TUD_RHPORT);
 
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
   // RTOS forever loop
-  while (1)
-  {
+  while (1) {
     // put this thread to waiting state until there is new events
     tud_task();
 
@@ -144,49 +153,42 @@ void usb_device_task(void* param)
 //--------------------------------------------------------------------+
 
 // Invoked when device is mounted
-void tud_mount_cb(void)
-{
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_MOUNTED), 0);
+void tud_mount_cb(void) {
+  blink_interval_ms = BLINK_MOUNTED;
 }
 
 // Invoked when device is unmounted
-void tud_umount_cb(void)
-{
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_NOT_MOUNTED), 0);
+void tud_umount_cb(void) {
+  blink_interval_ms = BLINK_NOT_MOUNTED;
 }
 
 // Invoked when usb bus is suspended
 // remote_wakeup_en : if host allow us  to perform remote wakeup
 // Within 7ms, device must draw an average of current less than 2.5 mA from bus
-void tud_suspend_cb(bool remote_wakeup_en)
-{
+void tud_suspend_cb(bool remote_wakeup_en) {
   (void) remote_wakeup_en;
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_SUSPENDED), 0);
+  blink_interval_ms = BLINK_SUSPENDED;
 }
 
 // Invoked when usb bus is resumed
-void tud_resume_cb(void)
-{
-  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_MOUNTED), 0);
+void tud_resume_cb(void) {
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
 }
 
 //--------------------------------------------------------------------+
 // USB CDC
 //--------------------------------------------------------------------+
-void cdc_task(void* params)
-{
+void cdc_task(void *params) {
   (void) params;
 
   // RTOS forever loop
-  while ( 1 )
-  {
+  while (1) {
     // connected() check for DTR bit
     // Most but not all terminal client set this when making connection
     // if ( tud_cdc_connected() )
     {
       // There are data available
-      while ( tud_cdc_available() )
-      {
+      while (tud_cdc_available()) {
         uint8_t buf[64];
 
         // read and echo back
@@ -209,35 +211,37 @@ void cdc_task(void* params)
 }
 
 // Invoked when cdc when line state changed e.g connected/disconnected
-void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts)
-{
+void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
   (void) itf;
   (void) rts;
 
   // TODO set some indicator
-  if ( dtr )
-  {
+  if (dtr) {
     // Terminal connected
-  }else
-  {
+  } else {
     // Terminal disconnected
   }
 }
 
 // Invoked when CDC interface received data from host
-void tud_cdc_rx_cb(uint8_t itf)
-{
+void tud_cdc_rx_cb(uint8_t itf) {
   (void) itf;
 }
 
 //--------------------------------------------------------------------+
 // BLINKING TASK
 //--------------------------------------------------------------------+
-void led_blinky_cb(TimerHandle_t xTimer)
-{
-  (void) xTimer;
+void led_blinking_task(void* param) {
+  (void) param;
+  static uint32_t start_ms = 0;
   static bool led_state = false;
 
-  board_led_write(led_state);
-  led_state = 1 - led_state; // toggle
+  while (1) {
+    // Blink every interval ms
+    vTaskDelay(blink_interval_ms / portTICK_PERIOD_MS);
+    start_ms += blink_interval_ms;
+
+    board_led_write(led_state);
+    led_state = 1 - led_state; // toggle
+  }
 }
diff --git a/examples/device/cdc_msc_freertos/src/msc_disk.c b/examples/device/cdc_msc_freertos/src/msc_disk.c
index a895f4738..c8a04bb74 100644
--- a/examples/device/cdc_msc_freertos/src/msc_disk.c
+++ b/examples/device/cdc_msc_freertos/src/msc_disk.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,7 +23,7 @@
  *
  */
 
-#include "bsp/board.h"
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 #if CFG_TUD_MSC
@@ -184,7 +184,7 @@ int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buff
   uint8_t const* addr = msc_disk[lba] + offset;
   memcpy(buffer, addr, bufsize);
 
-  return bufsize;
+  return (int32_t) bufsize;
 }
 
 // Callback invoked when received WRITE10 command.
@@ -203,7 +203,7 @@ int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t*
   (void) lba; (void) offset; (void) buffer;
 #endif
 
-  return bufsize;
+  return (int32_t) bufsize;
 }
 
 // Callback invoked when received an SCSI command not in built-in list below
@@ -237,14 +237,14 @@ int32_t tud_msc_scsi_cb (uint8_t lun, uint8_t const scsi_cmd[16], void* buffer,
   {
     if(in_xfer)
     {
-      memcpy(buffer, response, resplen);
+      memcpy(buffer, response, (size_t) resplen);
     }else
     {
       // SCSI output
     }
   }
 
-  return resplen;
+  return (int32_t) resplen;
 }
 
 #endif
diff --git a/examples/device/cdc_msc_freertos/src/tusb_config.h b/examples/device/cdc_msc_freertos/src/tusb_config.h
index 0ec8896b9..91efe7d40 100644
--- a/examples/device/cdc_msc_freertos/src/tusb_config.h
+++ b/examples/device/cdc_msc_freertos/src/tusb_config.h
@@ -54,7 +54,9 @@
 #endif
 
 // This examples use FreeRTOS
+#ifndef CFG_TUSB_OS
 #define CFG_TUSB_OS           OPT_OS_FREERTOS
+#endif
 
 // Espressif IDF requires "freertos/" prefix in include path
 #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
diff --git a/examples/device/cdc_msc_freertos/src/usb_descriptors.c b/examples/device/cdc_msc_freertos/src/usb_descriptors.c
index 30a712275..9c29701c7 100644
--- a/examples/device/cdc_msc_freertos/src/usb_descriptors.c
+++ b/examples/device/cdc_msc_freertos/src/usb_descriptors.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -23,6 +23,7 @@
  *
  */
 
+#include "bsp/board_api.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
@@ -212,53 +213,65 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// String Descriptor Index
+enum {
+  STRID_LANGID = 0,
+  STRID_MANUFACTURER,
+  STRID_PRODUCT,
+  STRID_SERIAL,
+};
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+char const *string_desc_arr[] =
 {
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "TinyUSB",                     // 1: Manufacturer
   "TinyUSB Device",              // 2: Product
-  "123456789012",                // 3: Serials, should use chip ID
+  NULL,                          // 3: Serials will use unique ID if possible
   "TinyUSB CDC",                 // 4: CDC Interface
   "TinyUSB MSC",                 // 5: MSC Interface
 };
 
-static uint16_t _desc_str[32];
+static uint16_t _desc_str[32 + 1];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
-{
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
   (void) langid;
+  size_t chr_count;
+
+  switch ( index ) {
+    case STRID_LANGID:
+      memcpy(&_desc_str[1], string_desc_arr[0], 2);
+      chr_count = 1;
+      break;
 
-  uint8_t chr_count;
+    case STRID_SERIAL:
+      chr_count = board_usb_get_serial(_desc_str + 1, 32);
+      break;
 
-  if ( index == 0)
-  {
-    memcpy(&_desc_str[1], string_desc_arr[0], 2);
-    chr_count = 1;
-  }else
-  {
-    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
-    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+    default:
+      // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+      // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
 
-    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+      if ( !(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])) ) return NULL;
 
-    const char* str = string_desc_arr[index];
+      const char *str = string_desc_arr[index];
 
-    // Cap at max char
-    chr_count = (uint8_t) strlen(str);
-    if ( chr_count > 31 ) chr_count = 31;
+      // Cap at max char
+      chr_count = strlen(str);
+      size_t const max_count = sizeof(_desc_str) / sizeof(_desc_str[0]) - 1; // -1 for string type
+      if ( chr_count > max_count ) chr_count = max_count;
 
-    // Convert ASCII string into UTF-16
-    for(uint8_t i=0; i<chr_count; i++)
-    {
-      _desc_str[1+i] = str[i];
-    }
+      // Convert ASCII string into UTF-16
+      for ( size_t i = 0; i < chr_count; i++ ) {
+        _desc_str[1 + i] = str[i];
+      }
+      break;
   }
 
   // first byte is length (including header), second byte is string type
-  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8 ) | (2*chr_count + 2));
+  _desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
 
   return _desc_str;
 }