diff --git a/Marlin/src/HAL/STM32/HAL.cpp b/Marlin/src/HAL/STM32/HAL.cpp
index b8db5b5e0b..06744f16b8 100644
--- a/Marlin/src/HAL/STM32/HAL.cpp
+++ b/Marlin/src/HAL/STM32/HAL.cpp
@@ -42,6 +42,11 @@
   #endif
 #endif
 
+#if HAS_SD_HOST_DRIVE
+  #include "msc_sd.h"
+  #include "usbd_cdc_if.h"
+#endif
+
 // ------------------------
 // Public Variables
 // ------------------------
@@ -88,6 +93,19 @@ void HAL_init() {
   #if ENABLED(EMERGENCY_PARSER) && USBD_USE_CDC
     USB_Hook_init();
   #endif
+
+  #if HAS_SD_HOST_DRIVE
+    MSC_SD_init();                         // Enable USB SD card access
+  #endif
+}
+
+// HAL idle task
+void HAL_idletask() {
+  #if HAS_SHARED_MEDIA
+    // Stm32duino currently doesn't have a "loop/idle" method
+    CDC_resume_receive();
+    CDC_continue_transmit();
+  #endif
 }
 
 void HAL_clear_reset_source() { __HAL_RCC_CLEAR_RESET_FLAGS(); }
diff --git a/Marlin/src/HAL/STM32/HAL.h b/Marlin/src/HAL/STM32/HAL.h
index 5eb827b970..8f6c0a5990 100644
--- a/Marlin/src/HAL/STM32/HAL.h
+++ b/Marlin/src/HAL/STM32/HAL.h
@@ -135,6 +135,8 @@ extern uint16_t HAL_adc_result;
 
 // Enable hooks into  setup for HAL
 void HAL_init();
+#define HAL_IDLETASK 1
+void HAL_idletask();
 
 // Clear reset reason
 void HAL_clear_reset_source();
diff --git a/Marlin/src/HAL/STM32/inc/Conditionals_adv.h b/Marlin/src/HAL/STM32/inc/Conditionals_adv.h
index e07c0d9cda..672d405d6b 100644
--- a/Marlin/src/HAL/STM32/inc/Conditionals_adv.h
+++ b/Marlin/src/HAL/STM32/inc/Conditionals_adv.h
@@ -21,6 +21,6 @@
  */
 #pragma once
 
-#if defined(USBD_USE_CDC_COMPOSITE) && DISABLED(NO_SD_HOST_DRIVE)
+#if defined(USBD_USE_CDC_MSC) && DISABLED(NO_SD_HOST_DRIVE)
   #define HAS_SD_HOST_DRIVE 1
 #endif
diff --git a/Marlin/src/HAL/STM32/msc_sd.cpp b/Marlin/src/HAL/STM32/msc_sd.cpp
new file mode 100644
index 0000000000..63ce7808f1
--- /dev/null
+++ b/Marlin/src/HAL/STM32/msc_sd.cpp
@@ -0,0 +1,112 @@
+/**
+ * Marlin 3D Printer Firmware
+ *
+ * Copyright (c) 2021 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ * Copyright (c) 2019 BigTreeTech [https://github.com/bigtreetech]
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#include "../../inc/MarlinConfigPre.h"
+
+#if defined(ARDUINO_ARCH_STM32) && !defined(STM32GENERIC) && HAS_SD_HOST_DRIVE
+
+#include "msc_sd.h"
+#include "../shared/Marduino.h"
+#include "usbd_core.h"
+#include <USB.h>
+#include <USBMscHandler.h>
+
+#define BLOCK_SIZE 512
+#define PRODUCT_ID 0x29
+
+#include "../../sd/cardreader.h"
+
+class Sd2CardUSBMscHandler : public USBMscHandler {
+public:
+  bool GetCapacity(uint32_t *pBlockNum, uint16_t *pBlockSize) {
+    *pBlockNum = card.getSd2Card().cardSize();
+    *pBlockSize = BLOCK_SIZE;
+    return true;
+  }
+
+  bool Write(uint8_t *pBuf, uint32_t blkAddr, uint16_t blkLen) {
+    auto sd2card = card.getSd2Card();
+    // single block
+    if (blkLen == 1) {
+      watchdog_refresh();
+      sd2card.writeBlock(blkAddr, pBuf);
+      return true;
+    }
+
+    // multi block optmization
+    sd2card.writeStart(blkAddr, blkLen);
+    while (blkLen--) {
+      watchdog_refresh();
+      sd2card.writeData(pBuf);
+      pBuf += BLOCK_SIZE;
+    }
+    sd2card.writeStop();
+    return true;
+  }
+
+  bool Read(uint8_t *pBuf, uint32_t blkAddr, uint16_t blkLen) {
+    auto sd2card = card.getSd2Card();
+    // single block
+    if (blkLen == 1) {
+      watchdog_refresh();
+      sd2card.readBlock(blkAddr, pBuf);
+      return true;
+    }
+
+    // multi block optmization
+    sd2card.readStart(blkAddr);
+    while (blkLen--) {
+      watchdog_refresh();
+      sd2card.readData(pBuf);
+      pBuf += BLOCK_SIZE;
+    }
+    sd2card.readStop();
+    return true;
+  }
+
+  bool IsReady() {
+    return card.isMounted();
+  }
+};
+
+Sd2CardUSBMscHandler usbMscHandler;
+
+/* USB Mass storage Standard Inquiry Data */
+uint8_t  Marlin_STORAGE_Inquirydata[] = { /* 36 */
+  /* LUN 0 */
+  0x00,
+  0x80,
+  0x02,
+  0x02,
+  (STANDARD_INQUIRY_DATA_LEN - 5),
+  0x00,
+  0x00,
+  0x00,
+  'M', 'A', 'R', 'L', 'I', 'N', ' ', ' ', /* Manufacturer : 8 bytes */
+  'P', 'r', 'o', 'd', 'u', 'c', 't', ' ', /* Product      : 16 Bytes */
+  ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
+  '0', '.', '0', '1',                     /* Version      : 4 Bytes */
+};
+
+USBMscHandler *pSingleMscHandler = &usbMscHandler;
+
+void MSC_SD_init() {
+  USBDevice.end();
+  delay(200);
+  USBDevice.begin();
+  USBDevice.registerMscHandlers(1, &pSingleMscHandler, Marlin_STORAGE_Inquirydata);
+}
+
+#endif // __STM32F1__ && HAS_SD_HOST_DRIVE
diff --git a/Marlin/src/HAL/STM32/msc_sd.h b/Marlin/src/HAL/STM32/msc_sd.h
new file mode 100644
index 0000000000..a8e5349f7c
--- /dev/null
+++ b/Marlin/src/HAL/STM32/msc_sd.h
@@ -0,0 +1,18 @@
+/**
+ * Marlin 3D Printer Firmware
+ *
+ * Copyright (c) 2021 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ * Copyright (c) 2019 BigTreeTech [https://github.com/bigtreetech]
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+void MSC_SD_init();
diff --git a/platformio.ini b/platformio.ini
index 2d81baa200..6008b943ec 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -1524,6 +1524,22 @@ build_flags       = ${stm32_flash_drive.build_flags}
   -DUSE_USB_HS_IN_FS
   -DUSBD_USE_CDC
 
+#
+# MKS Robin Nano V3 with USB Flash Drive Support and Shared Media
+# Currently, using a STM32duino fork, until USB Host and USB Device MSC get merged
+#
+[env:mks_robin_nano_v3_usb_flash_drive_msc]
+extends           = env:mks_robin_nano_v3
+platform_packages = framework-arduinoststm32@https://github.com/rhapsodyv/Arduino_Core_STM32/archive/usb-host-msc-cdc-msc.zip
+build_unflags     = ${common_stm32.build_unflags} -DUSBD_USE_CDC
+build_flags       = ${stm32_flash_drive.build_flags}
+  -DUSBCON
+  -DUSE_USBHOST_HS
+  -DUSBD_IRQ_PRIO=5
+  -DUSBD_IRQ_SUBPRIO=6
+  -DUSE_USB_HS_IN_FS
+  -DUSBD_USE_CDC_MSC
+
 #
 # Mingda MPX_ARM_MINI
 #