Merge branch 'master' into xfer-fifo

# Conflicts:
#	src/common/tusb_fifo.h

docs/integration.rst

@@ -59,7 +59,7 @@ Minimal Example
    }
 
    void USB1_IRQHandler(void) {
-     // forward interrupt port 0 to TinyUSB stack
+     // forward interrupt port 1 to TinyUSB stack
      tusb_int_handler(1, true);
    }
 

examples/build_system/cmake/cpu/cortex-m55.cmake

@@ -13,6 +13,7 @@ elseif (TOOLCHAIN STREQUAL "clang")
     --target=arm-none-eabi
     -mcpu=cortex-m55
     -mfpu=fpv5-d16
+    -mcmse
     )
   set(FREERTOS_PORT GCC_ARM_CM55_NTZ_NONSECURE CACHE INTERNAL "")
 
@@ -20,6 +21,7 @@ elseif (TOOLCHAIN STREQUAL "iar")
   set(TOOLCHAIN_COMMON_FLAGS
     --cpu cortex-m55
     --fpu VFPv5_D16
+    --cmse
     )
   set(FREERTOS_PORT IAR_ARM_CM55_NTZ_NONSECURE CACHE INTERNAL "")
 

examples/device/audio_test_multi_rate/src/usb_descriptors.c

@@ -119,8 +119,8 @@ TU_VERIFY_STATIC(sizeof(desc2_uac2_configuration) == CONFIG_UAC2_TOTAL_LEN, "Inc
 
 // device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
 tusb_desc_device_qualifier_t const desc_device_qualifier = {
-  .bLength            = sizeof(tusb_desc_device_t),
+  .bLength            = sizeof(tusb_desc_device_qualifier_t),
-  .bDescriptorType    = TUSB_DESC_DEVICE,
+  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
   .bcdUSB             = 0x0200,
 
   .bDeviceClass       = TUSB_CLASS_MISC,

examples/device/cdc_dual_ports/src/usb_descriptors.c

@@ -153,8 +153,8 @@ static uint8_t const desc_hs_configuration[] = {
 
 // device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
 static tusb_desc_device_qualifier_t const desc_device_qualifier = {
-  .bLength            = sizeof(tusb_desc_device_t),
+  .bLength            = sizeof(tusb_desc_device_qualifier_t),
-  .bDescriptorType    = TUSB_DESC_DEVICE,
+  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
   .bcdUSB             = USB_BCD,
 
   .bDeviceClass       = TUSB_CLASS_MISC,

examples/device/uac2_speaker_fb/src/audio_debug.py

@@ -2,13 +2,15 @@
 # Install python3 HID package https://pypi.org/project/hid/
 # Install python3 matplotlib package https://pypi.org/project/matplotlib/
 
-from ctypes import *
+from ctypes import Structure, c_uint32, c_uint8, c_int8, c_int16, c_uint16
+import signal
 try:
     import hid
     import matplotlib.pyplot as plt
     import matplotlib.animation as animation
 except:
     print("Missing import, please try 'pip install hid matplotlib' or consult your OS's python package manager.")
+    exit(1)
 
 # Example must be compiled with CFG_AUDIO_DEBUG=1
 VID = 0xcafe
@@ -29,6 +31,7 @@ class audio_debug_info_t (Structure):
 dev = hid.Device(VID, PID)
 
 if dev:
+    signal.signal(signal.SIGINT, signal.SIG_DFL)
     # Create figure for plotting
     fig = plt.figure()
     ax = fig.add_subplot(1, 1, 1)
@@ -61,10 +64,10 @@ if dev:
             ax.set_ylim(bottom=0, top=info.fifo_size)
 
             # Format plot
-            plt.title('FIFO information')
+            ax.set_title('FIFO information')
-            plt.grid()
+            ax.grid(True)
 
             print(f'Sample rate:{info.sample_rate} | Alt settings:{info.alt_settings} | Volume:{info.volume[:]}')
 
-    ani = animation.FuncAnimation(fig, animate, interval=10)
+    ani = animation.FuncAnimation(fig, animate, interval=10, cache_frame_data=False) # type: ignore
-    plt.show()
+    plt.show(block=True)

examples/device/uac2_speaker_fb/src/usb_descriptors.c

@@ -174,8 +174,8 @@ TU_VERIFY_STATIC(sizeof(desc_uac2_configuration) == CONFIG_UAC2_TOTAL_LEN, "Inco
 
 // device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
 tusb_desc_device_qualifier_t const desc_device_qualifier = {
-  .bLength            = sizeof(tusb_desc_device_t),
+  .bLength            = sizeof(tusb_desc_device_qualifier_t),
-  .bDescriptorType    = TUSB_DESC_DEVICE,
+  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
   .bcdUSB             = 0x0200,
 
   .bDeviceClass       = TUSB_CLASS_MISC,

examples/device/video_capture/src/usb_descriptors.c

@@ -385,8 +385,8 @@ static uint8_t * get_hs_configuration_desc(void) {
 
 // device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
 static tusb_desc_device_qualifier_t const desc_device_qualifier = {
-    .bLength            = sizeof(tusb_desc_device_t),
+    .bLength            = sizeof(tusb_desc_device_qualifier_t),
-    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
     .bcdUSB             = USB_BCD,
 
     .bDeviceClass       = TUSB_CLASS_MISC,

examples/device/video_capture_2ch/src/usb_descriptors.c

@@ -552,8 +552,8 @@ static uint8_t * get_hs_configuration_desc(void) {
 
 // device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
 static tusb_desc_device_qualifier_t const desc_device_qualifier = {
-    .bLength            = sizeof(tusb_desc_device_t),
+    .bLength            = sizeof(tusb_desc_device_qualifier_t),
-    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
     .bcdUSB             = USB_BCD,
 
     .bDeviceClass       = TUSB_CLASS_MISC,

hw/bsp/at32f402_405/family.c

@@ -75,16 +75,17 @@ void board_init(void)
   /* vbus ignore */
   board_vbus_sense_init();
 
-  /* configure systick */
+  #if CFG_TUSB_OS == OPT_OS_NONE
-  SysTick_Config(system_core_clock / 1000);
+    /* configure systick */
-
+    SysTick_Config(system_core_clock / 1000);
-  #if CFG_TUSB_OS == OPT_OS_FREERTOS
+    NVIC_SetPriority(OTGHS_IRQn, 0);
+    NVIC_SetPriority(OTGFS1_IRQn, 0);
+  #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+    // Explicitly disable systick to prevent its ISR from running before scheduler start
+    SysTick->CTRL &= ~1U;
     // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
     NVIC_SetPriority(OTGHS_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
     NVIC_SetPriority(OTGFS1_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
-  #else
-    NVIC_SetPriority(OTGHS_IRQn, 0);
-    NVIC_SetPriority(OTGFS1_IRQn, 0);
   #endif
 
   /* config led and key */

hw/bsp/at32f435_437/family.c

@@ -74,12 +74,14 @@ void board_init(void) {
   /* vbus ignore */
   board_vbus_sense_init();
 
-  SysTick_Config(SystemCoreClock / 1000);
 #if CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(OTGFS1_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
   NVIC_SetPriority(OTGFS2_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
 #else
+  SysTick_Config(SystemCoreClock / 1000);
   NVIC_SetPriority(OTGFS1_IRQn, 0);
   NVIC_SetPriority(OTGFS2_IRQn, 0);
 #endif

hw/bsp/imxrt/family.c

@@ -120,8 +120,9 @@ void board_init(void) {
 #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
-
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB_OTG1_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
   #ifdef USBPHY2

hw/bsp/kinetis_k/family.c

@@ -61,6 +61,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/kinetis_kl/family.c

@@ -59,6 +59,8 @@ void board_init(void)
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/lpc11/family.c

@@ -74,6 +74,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/lpc13/family.c

@@ -54,6 +54,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/lpc15/family.c

@@ -77,10 +77,12 @@ void board_init(void)
 {
   SystemCoreClockUpdate();
 
+#if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
-
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
-#if CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/lpc17/family.c

@@ -54,6 +54,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/lpc18/family.c

@@ -83,6 +83,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
   NVIC_SetPriority(USB1_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);

hw/bsp/lpc40/family.c

@@ -89,6 +89,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
 #endif

hw/bsp/lpc43/family.c

@@ -100,6 +100,8 @@ void board_init(void)
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
 #endif

hw/bsp/lpc51/family.c

@@ -57,6 +57,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/lpc54/family.c

@@ -108,10 +108,12 @@ void board_init(void) {
   // Init 96 MHz clock
   BootClockFROHF96M();
 
+#if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
-
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
-#if CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/lpc55/family.c

@@ -147,7 +147,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/maxim/family.c

@@ -66,6 +66,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
 #endif

hw/bsp/mcx/family.c

@@ -68,6 +68,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   #if CFG_TUSB_MCU == OPT_MCU_MCXN9
   NVIC_SetPriority(USB0_FS_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);

hw/bsp/mm32/family.c

@@ -70,8 +70,13 @@ void board_init(void) {
 //   usb clock
   USB_DeviceClockInit();
 
+#if CFG_TUSB_OS == OPT_OS_NONE
   SysTick_Config(SystemCoreClock / 1000);
   NVIC_SetPriority(SysTick_IRQn, 0x0);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
+#endif
 
   RCC_AHBPeriphClockCmd(RCC_AHBENR_GPIOA, ENABLE);
 

hw/bsp/msp432e4/family.c

@@ -85,6 +85,8 @@ void board_init(void)
 #if CFG_TUSB_OS == OPT_OS_NONE
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/nuc100_120/family.c

@@ -72,6 +72,9 @@ void board_init(void)
 #if CFG_TUSB_OS  == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(48000000 / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
 #endif
 
   GPIO_SetMode(LED_PORT, 1UL << LED_PIN, GPIO_PMD_OUTPUT);

hw/bsp/ra/family.c

@@ -118,6 +118,9 @@ void board_init(void) {
 
 #if CFG_TUSB_OS == OPT_OS_NONE
   SysTick_Config(SystemCoreClock / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
 #endif
 
   board_led_write(false);

hw/bsp/samd11/family.c

@@ -86,7 +86,12 @@ void board_init(void)
 
   // 1ms tick timer (samd SystemCoreClock may not correct)
   SystemCoreClock = CONF_CPU_FREQUENCY;
+#if CFG_TUSB_OS == OPT_OS_NONE
   SysTick_Config(CONF_CPU_FREQUENCY / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
+#endif
 
   // Led init
   gpio_set_pin_direction(LED_PIN, GPIO_DIRECTION_OUT);

hw/bsp/samd2x_l2x/family.c

@@ -154,6 +154,9 @@ void board_init(void) {
   SystemCoreClock = CONF_CPU_FREQUENCY;
 #if CFG_TUSB_OS == OPT_OS_NONE
   SysTick_Config(CONF_CPU_FREQUENCY / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
 #endif
 
   // Led init

hw/bsp/samd5x_e5x/family.c

@@ -103,7 +103,13 @@ void board_init(void) {
   // Update SystemCoreClock since it is hard coded with asf4 and not correct
   // Init 1ms tick timer (samd SystemCoreClock may not correct)
   SystemCoreClock = CONF_CPU_FREQUENCY;
+
+#if CFG_TUSB_OS == OPT_OS_NONE
   SysTick_Config(CONF_CPU_FREQUENCY / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
+#endif
 
   // Led init
   gpio_set_pin_direction(LED_PIN, GPIO_DIRECTION_OUT);

hw/bsp/same7x/family.c

@@ -129,6 +129,11 @@ void board_init(void) {
 #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer (SystemCoreClock may not be correct after init)
   SysTick_Config(CONF_CPU_FREQUENCY / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
+  // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
+  NVIC_SetPriority((IRQn_Type) ID_USBHS, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
 #endif
 
   // Enable USB clock

hw/bsp/samg/family.c

@@ -88,6 +88,8 @@ void board_init(void) {
   // 1ms tick timer (samd SystemCoreClock may not correct)
   SysTick_Config(CONF_CPU_FREQUENCY / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   NVIC_SetPriority(UDP_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
 #endif
 

hw/bsp/stm32c0/family.c

@@ -68,7 +68,7 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32f0/family.c

@@ -62,7 +62,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32f1/family.c

@@ -77,8 +77,9 @@ void board_init(void) {
 #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
-
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB_HP_CAN1_TX_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
   NVIC_SetPriority(USB_LP_CAN1_RX0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);

hw/bsp/stm32f2/family.c

@@ -56,6 +56,9 @@ void board_init(void) {
   #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
+  #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   #endif
 
   all_rcc_clk_enable();

hw/bsp/stm32f3/family.c

@@ -68,10 +68,13 @@ void USBWakeUp_RMP_IRQHandler(void) {
 void board_init(void) {
   SystemClock_Config();
 
-  #if CFG_TUSB_OS == OPT_OS_NONE
+#if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
-  #endif
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
+#endif
 
   // Remap the USB interrupts
   __HAL_RCC_SYSCFG_CLK_ENABLE();

hw/bsp/stm32f4/family.c

@@ -102,7 +102,7 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32f7/family.c

@@ -105,7 +105,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32g0/family.c

@@ -65,7 +65,7 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32g4/family.c

@@ -77,7 +77,7 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32h5/family.c

@@ -88,7 +88,7 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
   #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32h7/family.c

@@ -130,7 +130,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000u);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1UL;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32h7rs/family.c

@@ -304,7 +304,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32l0/family.c

@@ -54,7 +54,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32l4/family.c

@@ -78,6 +78,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
 #if defined(USB_OTG_FS)
   NVIC_SetPriority(OTG_FS_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );

hw/bsp/stm32n6/family.c

@@ -140,7 +140,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32n6/family.cmake

@@ -44,11 +44,11 @@ set(STARTUP_FILE_GNU ${ST_CMSIS}/Source/Templates/gcc/startup_${MCU_VARIANT}.s)
 set(STARTUP_FILE_Clang ${STARTUP_FILE_GNU})
 set(STARTUP_FILE_IAR ${ST_CMSIS}/Source/Templates/iar/startup_${MCU_VARIANT}.s)
 if(NOT DEFINED LD_FILE_GNU)
-set(LD_FILE_GNU ${ST_CMSIS}/Source/Templates/gcc/linker/${MCU_VARIANT}_flash.ld)
+set(LD_FILE_GNU ${ST_CMSIS}/Source/Templates/gcc/linker/${MCU_VARIANT}_axisram2_fsbl.ld)
 endif()
 set(LD_FILE_Clang ${LD_FILE_GNU})
 if(NOT DEFINED LD_FILE_IAR)
-  set(LD_FILE_IAR ${ST_CMSIS}/Source/Templates/iar/linker/${MCU_VARIANT}_flash.icf)
+  set(LD_FILE_IAR ${ST_CMSIS}/Source/Templates/iar/linker/${MCU_VARIANT}_axisram2_fsbl.icf)
 endif()
 
 #------------------------------------

hw/bsp/stm32u0/family.c

@@ -70,6 +70,14 @@ void board_init(void) {
 #endif
   __HAL_RCC_PWR_CLK_ENABLE();
 
+#if CFG_TUSB_OS == OPT_OS_NONE
+  // 1ms tick timer
+  SysTick_Config(SystemCoreClock / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
+#endif
+
   // LED
   GPIO_InitTypeDef  GPIO_InitStruct;
   GPIO_InitStruct.Pin = LED_PIN;

hw/bsp/stm32u5/family.c

@@ -90,6 +90,9 @@ void board_init(void) {
 #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
+#elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
 #endif
 
   GPIO_InitTypeDef GPIO_InitStruct;

hw/bsp/stm32wb/family.c

@@ -64,7 +64,7 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/stm32wba/family.c

@@ -131,7 +131,7 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
   #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

hw/bsp/tm4c/family.c

@@ -77,6 +77,8 @@ void board_init(void) {
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
+  SysTick->CTRL &= ~1U;
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
   NVIC_SetPriority(USB0_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
 #endif

hw/bsp/xmc4000/family.c

@@ -78,7 +78,7 @@ void board_init(void) {
   SysTick_Config(SystemCoreClock / 1000);
 
 #elif CFG_TUSB_OS == OPT_OS_FREERTOS
-  // Explicitly disable systick to prevent its ISR runs before scheduler start
+  // Explicitly disable systick to prevent its ISR from running before scheduler start
   SysTick->CTRL &= ~1U;
 
   // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )

src/common/tusb_fifo.h

@@ -244,7 +244,9 @@ TU_ATTR_ALWAYS_INLINE static inline uint16_t tu_fifo_depth(const tu_fifo_t *f) {
 }
 
 TU_ATTR_ALWAYS_INLINE static inline bool tu_fifo_empty(const tu_fifo_t *f) {
-  return f->wr_idx == f->rd_idx;
+  const uint16_t wr_idx = f->wr_idx;
+  const uint16_t rd_idx = f->rd_idx;
+  return wr_idx == rd_idx;
 }
 
 // return number of items in fifo, capped to fifo's depth

src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c

@@ -293,7 +293,11 @@ static void handle_ctr_tx(uint32_t ep_id) {
       return;
     }
     xfer->iso_in_sending = false;
+#if FSDEV_USE_SBUF_ISO == 0
     uint8_t buf_id = (ep_reg & USB_EP_DTOG_TX) ? 0 : 1;
+#else
+    uint8_t buf_id = BTABLE_BUF_TX;
+#endif
     btable_set_count(ep_id, buf_id, 0);
   }
 
@@ -774,7 +778,12 @@ static bool edpt_xfer(uint8_t rhport, uint8_t ep_num, tusb_dir_t dir) {
 
     uint16_t cnt = tu_min16(xfer->total_len, xfer->max_packet_size);
 
-    if (ep_is_iso(ep_reg)) {
+#if FSDEV_USE_SBUF_ISO == 0
+    bool const dbl_buf = ep_is_iso(ep_reg);
+#else
+    bool const dbl_buf = false;
+#endif
+    if (dbl_buf) {
       btable_set_rx_bufsize(ep_idx, 0, cnt);
       btable_set_rx_bufsize(ep_idx, 1, cnt);
     } else {

src/portable/st/stm32_fsdev/fsdev_stm32.h

@@ -202,8 +202,7 @@
   #include "stm32u0xx.h"
   #define FSDEV_PMA_SIZE (1024u)
   #define FSDEV_BUS_32BIT
-  // Disable SBUF_ISO on U0 for now due to bad performance (audio glitching)
+  #define FSDEV_HAS_SBUF_ISO 1
-  #define FSDEV_HAS_SBUF_ISO 0
   #define USB USB_DRD_FS
 
   #define USB_EP_CTR_RX USB_EP_VTRX