diff --git a/src/class/msc/msc.h b/src/class/msc/msc.h
new file mode 100644
index 0000000..84b6e4d
--- /dev/null
+++ b/src/class/msc/msc.h
@@ -0,0 +1,382 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#ifndef _TUSB_MSC_H_
+#define _TUSB_MSC_H_
+
+#include "common/tusb_common.h"
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+//--------------------------------------------------------------------+
+// Mass Storage Class Constant
+//--------------------------------------------------------------------+
+/// MassStorage Subclass
+typedef enum
+{
+  MSC_SUBCLASS_RBC = 1 , ///< Reduced Block Commands (RBC) T10 Project 1240-D
+  MSC_SUBCLASS_SFF_MMC , ///< SFF-8020i, MMC-2 (ATAPI). Typically used by a CD/DVD device
+  MSC_SUBCLASS_QIC     , ///< QIC-157. Typically used by a tape device
+  MSC_SUBCLASS_UFI     , ///< UFI. Typically used by Floppy Disk Drive (FDD) device
+  MSC_SUBCLASS_SFF     , ///< SFF-8070i. Can be used by Floppy Disk Drive (FDD) device
+  MSC_SUBCLASS_SCSI      ///< SCSI transparent command set
+}msc_subclass_type_t;
+
+enum {
+  MSC_CBW_SIGNATURE = 0x43425355, ///< Constant value of 43425355h (little endian)
+  MSC_CSW_SIGNATURE = 0x53425355  ///< Constant value of 53425355h (little endian)
+};
+
+/// \brief MassStorage Protocol.
+/// \details CBI only approved to use with full-speed floopy disk & should not used with highspeed or device other than floopy
+typedef enum
+{
+  MSC_PROTOCOL_CBI              = 0 ,  ///< Control/Bulk/Interrupt protocol (with command completion interrupt)
+  MSC_PROTOCOL_CBI_NO_INTERRUPT = 1 ,  ///< Control/Bulk/Interrupt protocol (without command completion interrupt)
+  MSC_PROTOCOL_BOT              = 0x50 ///< Bulk-Only Transport
+}msc_protocol_type_t;
+
+/// MassStorage Class-Specific Control Request
+typedef enum
+{
+  MSC_REQ_GET_MAX_LUN = 254, ///< The Get Max LUN device request is used to determine the number of logical units supported by the device. Logical Unit Numbers on the device shall be numbered contiguously starting from LUN 0 to a maximum LUN of 15
+  MSC_REQ_RESET       = 255  ///< This request is used to reset the mass storage device and its associated interface. This class-specific request shall ready the device for the next CBW from the host.
+}msc_request_type_t;
+
+/// \brief Command Block Status Values
+/// \details Indicates the success or failure of the command. The device shall set this byte to zero if the command completed
+/// successfully. A non-zero value shall indicate a failure during command execution according to the following
+typedef enum
+{
+  MSC_CSW_STATUS_PASSED = 0 , ///< MSC_CSW_STATUS_PASSED
+  MSC_CSW_STATUS_FAILED     , ///< MSC_CSW_STATUS_FAILED
+  MSC_CSW_STATUS_PHASE_ERROR  ///< MSC_CSW_STATUS_PHASE_ERROR
+}msc_csw_status_t;
+
+/// Command Block Wrapper
+typedef struct TU_ATTR_PACKED
+{
+  uint32_t signature;   ///< Signature that helps identify this data packet as a CBW. The signature field shall contain the value 43425355h (little endian), indicating a CBW.
+  uint32_t tag;         ///< Tag sent by the host. The device shall echo the contents of this field back to the host in the dCSWTagfield of the associated CSW. The dCSWTagpositively associates a CSW with the corresponding CBW.
+  uint32_t total_bytes; ///< The number of bytes of data that the host expects to transfer on the Bulk-In or Bulk-Out endpoint (as indicated by the Direction bit) during the execution of this command. If this field is zero, the device and the host shall transfer no data between the CBW and the associated CSW, and the device shall ignore the value of the Direction bit in bmCBWFlags.
+  uint8_t dir;          ///< Bit 7 of this field define transfer direction \n - 0 : Data-Out from host to the device. \n - 1 : Data-In from the device to the host.
+  uint8_t lun;          ///< The device Logical Unit Number (LUN) to which the command block is being sent. For devices that support multiple LUNs, the host shall place into this field the LUN to which this command block is addressed. Otherwise, the host shall set this field to zero.
+  uint8_t cmd_len;      ///< The valid length of the CBWCBin bytes. This defines the valid length of the command block. The only legal values are 1 through 16
+  uint8_t command[16];  ///< The command block to be executed by the device. The device shall interpret the first cmd_len bytes in this field as a command block
+}msc_cbw_t;
+
+TU_VERIFY_STATIC(sizeof(msc_cbw_t) == 31, "size is not correct");
+
+/// Command Status Wrapper
+typedef struct TU_ATTR_PACKED
+{
+  uint32_t signature    ; ///< Signature that helps identify this data packet as a CSW. The signature field shall contain the value 53425355h (little endian), indicating CSW.
+  uint32_t tag          ; ///< The device shall set this field to the value received in the dCBWTag of the associated CBW.
+  uint32_t data_residue ; ///< For Data-Out the device shall report in the dCSWDataResiduethe difference between the amount of data expected as stated in the dCBWDataTransferLength, and the actual amount of data processed by the device. For Data-In the device shall report in the dCSWDataResiduethe difference between the amount of data expected as stated in the dCBWDataTransferLengthand the actual amount of relevant data sent by the device
+  uint8_t  status       ; ///< indicates the success or failure of the command. Values from \ref msc_csw_status_t
+}msc_csw_t;
+
+TU_VERIFY_STATIC(sizeof(msc_csw_t) == 13, "size is not correct");
+
+//--------------------------------------------------------------------+
+// SCSI Constant
+//--------------------------------------------------------------------+
+
+/// SCSI Command Operation Code
+typedef enum
+{
+  SCSI_CMD_TEST_UNIT_READY              = 0x00, ///< The SCSI Test Unit Ready command is used to determine if a device is ready to transfer data (read/write), i.e. if a disk has spun up, if a tape is loaded and ready etc. The device does not perform a self-test operation.
+  SCSI_CMD_INQUIRY                      = 0x12, ///< The SCSI Inquiry command is used to obtain basic information from a target device.
+  SCSI_CMD_MODE_SELECT_6                = 0x15, ///<  provides a means for the application client to specify medium, logical unit, or peripheral device parameters to the device server. Device servers that implement the MODE SELECT(6) command shall also implement the MODE SENSE(6) command. Application clients should issue MODE SENSE(6) prior to each MODE SELECT(6) to determine supported mode pages, page lengths, and other parameters.
+  SCSI_CMD_MODE_SENSE_6                 = 0x1A, ///< provides a means for a device server to report parameters to an application client. It is a complementary command to the MODE SELECT(6) command. Device servers that implement the MODE SENSE(6) command shall also implement the MODE SELECT(6) command.
+  SCSI_CMD_START_STOP_UNIT              = 0x1B,
+  SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL = 0x1E,
+  SCSI_CMD_READ_CAPACITY_10             = 0x25, ///< The SCSI Read Capacity command is used to obtain data capacity information from a target device.
+  SCSI_CMD_REQUEST_SENSE                = 0x03, ///< The SCSI Request Sense command is part of the SCSI computer protocol standard. This command is used to obtain sense data -- status/error information -- from a target device.
+  SCSI_CMD_READ_FORMAT_CAPACITY         = 0x23, ///< The command allows the Host to request a list of the possible format capacities for an installed writable media. This command also has the capability to report the writable capacity for a media when it is installed
+  SCSI_CMD_READ_10                      = 0x28, ///< The READ (10) command requests that the device server read the specified logical block(s) and transfer them to the data-in buffer.
+  SCSI_CMD_WRITE_10                     = 0x2A, ///< The WRITE (10) command requests thatthe device server transfer the specified logical block(s) from the data-out buffer and write them.
+}scsi_cmd_type_t;
+
+/// SCSI Sense Key
+typedef enum
+{
+  SCSI_SENSE_NONE            = 0x00, ///< no specific Sense Key. This would be the case for a successful command
+  SCSI_SENSE_RECOVERED_ERROR = 0x01, ///< ndicates the last command completed successfully with some recovery action performed by the disc drive.
+  SCSI_SENSE_NOT_READY       = 0x02, ///< Indicates the logical unit addressed cannot be accessed.
+  SCSI_SENSE_MEDIUM_ERROR    = 0x03, ///< Indicates the command terminated with a non-recovered error condition.
+  SCSI_SENSE_HARDWARE_ERROR  = 0x04, ///< Indicates the disc drive detected a nonrecoverable hardware failure while performing the command or during a self test.
+  SCSI_SENSE_ILLEGAL_REQUEST = 0x05, ///< Indicates an illegal parameter in the command descriptor block or in the additional parameters
+  SCSI_SENSE_UNIT_ATTENTION  = 0x06, ///< Indicates the disc drive may have been reset.
+  SCSI_SENSE_DATA_PROTECT    = 0x07, ///< Indicates that a command that reads or writes the medium was attempted on a block that is protected from this operation. The read or write operation is not performed.
+  SCSI_SENSE_FIRMWARE_ERROR  = 0x08, ///< Vendor specific sense key.
+  SCSI_SENSE_ABORTED_COMMAND = 0x0b, ///< Indicates the disc drive aborted the command.
+  SCSI_SENSE_EQUAL           = 0x0c, ///< Indicates a SEARCH DATA command has satisfied an equal comparison.
+  SCSI_SENSE_VOLUME_OVERFLOW = 0x0d, ///< Indicates a buffered peripheral device has reached the end of medium partition and data remains in the buffer that has not been written to the medium.
+  SCSI_SENSE_MISCOMPARE      = 0x0e  ///< ndicates that the source data did not match the data read from the medium.
+}scsi_sense_key_type_t;
+
+//--------------------------------------------------------------------+
+// SCSI Primary Command (SPC-4)
+//--------------------------------------------------------------------+
+
+/// SCSI Test Unit Ready Command
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t cmd_code    ; ///< SCSI OpCode for \ref SCSI_CMD_TEST_UNIT_READY
+  uint8_t lun         ; ///< Logical Unit
+  uint8_t reserved[3] ;
+  uint8_t control     ;
+} scsi_test_unit_ready_t;
+
+TU_VERIFY_STATIC(sizeof(scsi_test_unit_ready_t) == 6, "size is not correct");
+
+/// SCSI Inquiry Command
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t cmd_code     ; ///< SCSI OpCode for \ref SCSI_CMD_INQUIRY
+  uint8_t reserved1    ;
+  uint8_t page_code    ;
+  uint8_t reserved2    ;
+  uint8_t alloc_length ; ///< specifies the maximum number of bytes that USB host has allocated in the Data-In Buffer. An allocation length of zero specifies that no data shall be transferred.
+  uint8_t control      ;
+} scsi_inquiry_t, scsi_request_sense_t;
+
+TU_VERIFY_STATIC(sizeof(scsi_inquiry_t) == 6, "size is not correct");
+
+/// SCSI Inquiry Response Data
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t peripheral_device_type     : 5;
+  uint8_t peripheral_qualifier       : 3;
+
+  uint8_t                            : 7;
+  uint8_t is_removable               : 1;
+
+  uint8_t version;
+
+  uint8_t response_data_format       : 4;
+  uint8_t hierarchical_support       : 1;
+  uint8_t normal_aca                 : 1;
+  uint8_t                            : 2;
+
+  uint8_t additional_length;
+
+  uint8_t protect                    : 1;
+  uint8_t                            : 2;
+  uint8_t third_party_copy           : 1;
+  uint8_t target_port_group_support  : 2;
+  uint8_t access_control_coordinator : 1;
+  uint8_t scc_support                : 1;
+
+  uint8_t addr16                     : 1;
+  uint8_t                            : 3;
+  uint8_t multi_port                 : 1;
+  uint8_t                            : 1; // vendor specific
+  uint8_t enclosure_service          : 1;
+  uint8_t                            : 1;
+
+  uint8_t                            : 1; // vendor specific
+  uint8_t cmd_que                    : 1;
+  uint8_t                            : 2;
+  uint8_t sync                       : 1;
+  uint8_t wbus16                     : 1;
+  uint8_t                            : 2;
+
+  uint8_t vendor_id[8]  ; ///< 8 bytes of ASCII data identifying the vendor of the product.
+  uint8_t product_id[16]; ///< 16 bytes of ASCII data defined by the vendor.
+  uint8_t product_rev[4]; ///< 4 bytes of ASCII data defined by the vendor.
+} scsi_inquiry_resp_t;
+
+TU_VERIFY_STATIC(sizeof(scsi_inquiry_resp_t) == 36, "size is not correct");
+
+
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t response_code : 7; ///< 70h - current errors, Fixed Format 71h - deferred errors, Fixed Format
+  uint8_t valid         : 1;
+
+  uint8_t reserved;
+
+  uint8_t sense_key     : 4;
+  uint8_t               : 1;
+  uint8_t ili           : 1; ///< Incorrect length indicator
+  uint8_t end_of_medium : 1;
+  uint8_t filemark      : 1;
+
+  uint32_t information;
+  uint8_t  add_sense_len;
+  uint32_t command_specific_info;
+  uint8_t  add_sense_code;
+  uint8_t  add_sense_qualifier;
+  uint8_t  field_replaceable_unit_code;
+
+  uint8_t  sense_key_specific[3]; ///< sense key specific valid bit is bit 7 of key[0], aka MSB in Big Endian layout
+
+} scsi_sense_fixed_resp_t;
+
+TU_VERIFY_STATIC(sizeof(scsi_sense_fixed_resp_t) == 18, "size is not correct");
+
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t cmd_code     ; ///< SCSI OpCode for \ref SCSI_CMD_MODE_SENSE_6
+
+  uint8_t : 3;
+  uint8_t disable_block_descriptor : 1;
+  uint8_t : 4;
+
+  uint8_t page_code : 6;
+  uint8_t page_control : 2;
+
+  uint8_t subpage_code;
+  uint8_t alloc_length;
+  uint8_t control;
+} scsi_mode_sense6_t;
+
+TU_VERIFY_STATIC( sizeof(scsi_mode_sense6_t) == 6, "size is not correct");
+
+// This is only a Mode parameter header(6).
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t data_len;
+  uint8_t medium_type;
+
+  uint8_t reserved : 7;
+  bool write_protected : 1;
+
+  uint8_t block_descriptor_len;
+} scsi_mode_sense6_resp_t;
+
+TU_VERIFY_STATIC( sizeof(scsi_mode_sense6_resp_t) == 4, "size is not correct");
+
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t cmd_code; ///< SCSI OpCode for \ref SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL
+  uint8_t reserved[3];
+  uint8_t prohibit_removal;
+  uint8_t control;
+} scsi_prevent_allow_medium_removal_t;
+
+TU_VERIFY_STATIC( sizeof(scsi_prevent_allow_medium_removal_t) == 6, "size is not correct");
+
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t cmd_code;
+
+  uint8_t immded : 1;
+  uint8_t        : 7;
+
+  uint8_t TU_RESERVED;
+
+  uint8_t power_condition_mod : 4;
+  uint8_t                     : 4;
+
+  uint8_t start           : 1;
+  uint8_t load_eject      : 1;
+  uint8_t no_flush        : 1;
+  uint8_t                 : 1;
+  uint8_t power_condition : 4;
+
+  uint8_t control;
+} scsi_start_stop_unit_t;
+
+TU_VERIFY_STATIC( sizeof(scsi_start_stop_unit_t) == 6, "size is not correct");
+
+//--------------------------------------------------------------------+
+// SCSI MMC
+//--------------------------------------------------------------------+
+/// SCSI Read Format Capacity: Write Capacity
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t cmd_code;
+  uint8_t reserved[6];
+  uint16_t alloc_length;
+  uint8_t control;
+} scsi_read_format_capacity_t;
+
+TU_VERIFY_STATIC( sizeof(scsi_read_format_capacity_t) == 10, "size is not correct");
+
+typedef struct TU_ATTR_PACKED{
+  uint8_t reserved[3];
+  uint8_t list_length; /// must be 8*n, length in bytes of formattable capacity descriptor followed it.
+
+  uint32_t block_num; /// Number of Logical Blocks
+  uint8_t  descriptor_type; // 00: reserved, 01 unformatted media , 10 Formatted media, 11 No media present
+
+  uint8_t  reserved2;
+  uint16_t block_size_u16;
+
+} scsi_read_format_capacity_data_t;
+
+TU_VERIFY_STATIC( sizeof(scsi_read_format_capacity_data_t) == 12, "size is not correct");
+
+//--------------------------------------------------------------------+
+// SCSI Block Command (SBC-3)
+// NOTE: All data in SCSI command are in Big Endian
+//--------------------------------------------------------------------+
+
+/// SCSI Read Capacity 10 Command: Read Capacity
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t  cmd_code                 ; ///< SCSI OpCode for \ref SCSI_CMD_READ_CAPACITY_10
+  uint8_t  reserved1                ;
+  uint32_t lba                      ; ///< The first Logical Block Address (LBA) accessed by this command
+  uint16_t reserved2                ;
+  uint8_t  partial_medium_indicator ;
+  uint8_t  control                  ;
+} scsi_read_capacity10_t;
+
+TU_VERIFY_STATIC(sizeof(scsi_read_capacity10_t) == 10, "size is not correct");
+
+/// SCSI Read Capacity 10 Response Data
+typedef struct {
+  uint32_t last_lba   ; ///< The last Logical Block Address of the device
+  uint32_t block_size ; ///< Block size in bytes
+} scsi_read_capacity10_resp_t;
+
+TU_VERIFY_STATIC(sizeof(scsi_read_capacity10_resp_t) == 8, "size is not correct");
+
+/// SCSI Read 10 Command
+typedef struct TU_ATTR_PACKED
+{
+  uint8_t  cmd_code    ; ///< SCSI OpCode
+  uint8_t  reserved    ; // has LUN according to wiki
+  uint32_t lba         ; ///< The first Logical Block Address (LBA) accessed by this command
+  uint8_t  reserved2   ;
+  uint16_t block_count ; ///< Number of Blocks used by this command
+  uint8_t  control     ;
+} scsi_read10_t, scsi_write10_t;
+
+TU_VERIFY_STATIC(sizeof(scsi_read10_t) == 10, "size is not correct");
+TU_VERIFY_STATIC(sizeof(scsi_write10_t) == 10, "size is not correct");
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* _TUSB_MSC_H_ */
diff --git a/src/class/msc/msc_device.c b/src/class/msc/msc_device.c
new file mode 100644
index 0000000..97837b1
--- /dev/null
+++ b/src/class/msc/msc_device.c
@@ -0,0 +1,939 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "tusb_option.h"
+
+#if (TUSB_OPT_DEVICE_ENABLED && CFG_TUD_MSC)
+
+#include "device/usbd.h"
+#include "device/usbd_pvt.h"
+#include "device/dcd.h"         // for faking dcd_event_xfer_complete
+
+#include "msc_device.h"
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF
+//--------------------------------------------------------------------+
+
+// Can be selectively disabled to reduce logging when troubleshooting other driver
+#define MSC_DEBUG   2
+
+enum
+{
+  MSC_STAGE_CMD  = 0,
+  MSC_STAGE_DATA,
+  MSC_STAGE_STATUS,
+  MSC_STAGE_STATUS_SENT,
+  MSC_STAGE_NEED_RESET,
+};
+
+typedef struct
+{
+  // TODO optimize alignment
+  CFG_TUSB_MEM_ALIGN msc_cbw_t cbw;
+  CFG_TUSB_MEM_ALIGN msc_csw_t csw;
+
+  uint8_t  itf_num;
+  uint8_t  ep_in;
+  uint8_t  ep_out;
+
+  // Bulk Only Transfer (BOT) Protocol
+  uint8_t  stage;
+  uint32_t total_len;   // byte to be transferred, can be smaller than total_bytes in cbw
+  uint32_t xferred_len; // numbered of bytes transferred so far in the Data Stage
+
+  // Sense Response Data
+  uint8_t sense_key;
+  uint8_t add_sense_code;
+  uint8_t add_sense_qualifier;
+}mscd_interface_t;
+
+CFG_TUSB_MEM_SECTION CFG_TUSB_MEM_ALIGN static mscd_interface_t _mscd_itf;
+CFG_TUSB_MEM_SECTION CFG_TUSB_MEM_ALIGN static uint8_t _mscd_buf[CFG_TUD_MSC_EP_BUFSIZE];
+
+//--------------------------------------------------------------------+
+// INTERNAL OBJECT & FUNCTION DECLARATION
+//--------------------------------------------------------------------+
+static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_t* buffer, uint32_t bufsize);
+static void proc_read10_cmd(uint8_t rhport, mscd_interface_t* p_msc);
+
+static void proc_write10_cmd(uint8_t rhport, mscd_interface_t* p_msc);
+static void proc_write10_new_data(uint8_t rhport, mscd_interface_t* p_msc, uint32_t xferred_bytes);
+
+TU_ATTR_ALWAYS_INLINE static inline bool is_data_in(uint8_t dir)
+{
+  return tu_bit_test(dir, 7);
+}
+
+static inline bool send_csw(uint8_t rhport, mscd_interface_t* p_msc)
+{
+  // Data residue is always = host expect - actual transferred
+  p_msc->csw.data_residue = p_msc->cbw.total_bytes - p_msc->xferred_len;
+
+  p_msc->stage = MSC_STAGE_STATUS_SENT;
+  return usbd_edpt_xfer(rhport, p_msc->ep_in , (uint8_t*) &p_msc->csw, sizeof(msc_csw_t));
+}
+
+static inline bool prepare_cbw(uint8_t rhport, mscd_interface_t* p_msc)
+{
+  p_msc->stage = MSC_STAGE_CMD;
+  return usbd_edpt_xfer(rhport, p_msc->ep_out, (uint8_t*) &p_msc->cbw, sizeof(msc_cbw_t));
+}
+
+static void fail_scsi_op(uint8_t rhport, mscd_interface_t* p_msc, uint8_t status)
+{
+  msc_cbw_t const * p_cbw = &p_msc->cbw;
+  msc_csw_t       * p_csw = &p_msc->csw;
+
+  p_csw->status       = status;
+  p_csw->data_residue = p_msc->cbw.total_bytes - p_msc->xferred_len;
+  p_msc->stage        = MSC_STAGE_STATUS;
+
+  // failed but sense key is not set: default to Illegal Request
+  if ( p_msc->sense_key == 0 ) tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_ILLEGAL_REQUEST, 0x20, 0x00);
+
+  // If there is data stage and not yet complete, stall it
+  if ( p_cbw->total_bytes && p_csw->data_residue )
+  {
+    if ( is_data_in(p_cbw->dir) )
+    {
+      usbd_edpt_stall(rhport, p_msc->ep_in);
+    }
+    else
+    {
+      usbd_edpt_stall(rhport, p_msc->ep_out);
+    }
+  }
+}
+
+static inline uint32_t rdwr10_get_lba(uint8_t const command[])
+{
+  // use offsetof to avoid pointer to the odd/unaligned address
+  uint32_t const lba = tu_unaligned_read32(command + offsetof(scsi_write10_t, lba));
+
+  // lba is in Big Endian
+  return tu_ntohl(lba);
+}
+
+static inline uint16_t rdwr10_get_blockcount(msc_cbw_t const* cbw)
+{
+  uint16_t const block_count = tu_unaligned_read16(cbw->command + offsetof(scsi_write10_t, block_count));
+  return tu_ntohs(block_count);
+}
+
+static inline uint16_t rdwr10_get_blocksize(msc_cbw_t const* cbw)
+{
+  // first extract block count in the command
+  uint16_t const block_count = rdwr10_get_blockcount(cbw);
+
+  // invalid block count
+  if (block_count == 0) return 0;
+
+  return (uint16_t) (cbw->total_bytes / block_count);
+}
+
+uint8_t rdwr10_validate_cmd(msc_cbw_t const* cbw)
+{
+  uint8_t status = MSC_CSW_STATUS_PASSED;
+  uint16_t const block_count = rdwr10_get_blockcount(cbw);
+
+  if ( cbw->total_bytes == 0 )
+  {
+    if ( block_count )
+    {
+      TU_LOG(MSC_DEBUG, "  SCSI case 2 (Hn < Di) or case 3 (Hn < Do) \r\n");
+      status = MSC_CSW_STATUS_PHASE_ERROR;
+    }else
+    {
+      // no data transfer, only exist in complaint test suite
+    }
+  }else
+  {
+    if ( SCSI_CMD_READ_10 == cbw->command[0] && !is_data_in(cbw->dir) )
+    {
+      TU_LOG(MSC_DEBUG, "  SCSI case 10 (Ho <> Di)\r\n");
+      status = MSC_CSW_STATUS_PHASE_ERROR;
+    }
+    else if ( SCSI_CMD_WRITE_10 == cbw->command[0] && is_data_in(cbw->dir) )
+    {
+      TU_LOG(MSC_DEBUG, "  SCSI case 8 (Hi <> Do)\r\n");
+      status = MSC_CSW_STATUS_PHASE_ERROR;
+    }
+    else if ( 0 == block_count )
+    {
+      TU_LOG(MSC_DEBUG, "  SCSI case 4 Hi > Dn (READ10) or case 9 Ho > Dn (WRITE10) \r\n");
+      status =  MSC_CSW_STATUS_FAILED;
+    }
+    else if ( cbw->total_bytes / block_count == 0 )
+    {
+      TU_LOG(MSC_DEBUG, " Computed block size = 0. SCSI case 7 Hi < Di (READ10) or case 13 Ho < Do (WRIT10)\r\n");
+      status = MSC_CSW_STATUS_PHASE_ERROR;
+    }
+  }
+
+  return status;
+}
+
+//--------------------------------------------------------------------+
+// Debug
+//--------------------------------------------------------------------+
+#if CFG_TUSB_DEBUG >= 2
+
+TU_ATTR_UNUSED static tu_lookup_entry_t const _msc_scsi_cmd_lookup[] =
+{
+  { .key = SCSI_CMD_TEST_UNIT_READY              , .data = "Test Unit Ready" },
+  { .key = SCSI_CMD_INQUIRY                      , .data = "Inquiry" },
+  { .key = SCSI_CMD_MODE_SELECT_6                , .data = "Mode_Select 6" },
+  { .key = SCSI_CMD_MODE_SENSE_6                 , .data = "Mode_Sense 6" },
+  { .key = SCSI_CMD_START_STOP_UNIT              , .data = "Start Stop Unit" },
+  { .key = SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL , .data = "Prevent Allow Medium Removal" },
+  { .key = SCSI_CMD_READ_CAPACITY_10             , .data = "Read Capacity10" },
+  { .key = SCSI_CMD_REQUEST_SENSE                , .data = "Request Sense" },
+  { .key = SCSI_CMD_READ_FORMAT_CAPACITY         , .data = "Read Format Capacity" },
+  { .key = SCSI_CMD_READ_10                      , .data = "Read10" },
+  { .key = SCSI_CMD_WRITE_10                     , .data = "Write10" }
+};
+
+TU_ATTR_UNUSED static tu_lookup_table_t const _msc_scsi_cmd_table =
+{
+  .count = TU_ARRAY_SIZE(_msc_scsi_cmd_lookup),
+  .items = _msc_scsi_cmd_lookup
+};
+
+#endif
+
+//--------------------------------------------------------------------+
+// APPLICATION API
+//--------------------------------------------------------------------+
+bool tud_msc_set_sense(uint8_t lun, uint8_t sense_key, uint8_t add_sense_code, uint8_t add_sense_qualifier)
+{
+  (void) lun;
+
+  _mscd_itf.sense_key           = sense_key;
+  _mscd_itf.add_sense_code      = add_sense_code;
+  _mscd_itf.add_sense_qualifier = add_sense_qualifier;
+
+  return true;
+}
+
+//--------------------------------------------------------------------+
+// USBD Driver API
+//--------------------------------------------------------------------+
+void mscd_init(void)
+{
+  tu_memclr(&_mscd_itf, sizeof(mscd_interface_t));
+}
+
+void mscd_reset(uint8_t rhport)
+{
+  (void) rhport;
+  tu_memclr(&_mscd_itf, sizeof(mscd_interface_t));
+}
+
+uint16_t mscd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len)
+{
+  // only support SCSI's BOT protocol
+  TU_VERIFY(TUSB_CLASS_MSC    == itf_desc->bInterfaceClass &&
+            MSC_SUBCLASS_SCSI == itf_desc->bInterfaceSubClass &&
+            MSC_PROTOCOL_BOT  == itf_desc->bInterfaceProtocol, 0);
+
+  // msc driver length is fixed
+  uint16_t const drv_len = sizeof(tusb_desc_interface_t) + 2*sizeof(tusb_desc_endpoint_t);
+
+  // Max length must be at least 1 interface + 2 endpoints
+  TU_ASSERT(max_len >= drv_len, 0);
+
+  mscd_interface_t * p_msc = &_mscd_itf;
+  p_msc->itf_num = itf_desc->bInterfaceNumber;
+
+  // Open endpoint pair
+  TU_ASSERT( usbd_open_edpt_pair(rhport, tu_desc_next(itf_desc), 2, TUSB_XFER_BULK, &p_msc->ep_out, &p_msc->ep_in), 0 );
+
+  // Prepare for Command Block Wrapper
+  TU_ASSERT( prepare_cbw(rhport, p_msc), drv_len);
+
+  return drv_len;
+}
+
+static void proc_bot_reset(mscd_interface_t* p_msc)
+{
+  p_msc->stage       = MSC_STAGE_CMD;
+  p_msc->total_len   = 0;
+  p_msc->xferred_len = 0;
+
+  p_msc->sense_key           = 0;
+  p_msc->add_sense_code      = 0;
+  p_msc->add_sense_qualifier = 0;
+}
+
+// Invoked when a control transfer occurred on an interface of this class
+// Driver response accordingly to the request and the transfer stage (setup/data/ack)
+// return false to stall control endpoint (e.g unsupported request)
+bool mscd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request)
+{
+  // nothing to do with DATA & ACK stage
+  if (stage != CONTROL_STAGE_SETUP) return true;
+
+  mscd_interface_t* p_msc = &_mscd_itf;
+
+  // Clear Endpoint Feature (stall) for recovery
+  if ( TUSB_REQ_TYPE_STANDARD     == request->bmRequestType_bit.type      &&
+       TUSB_REQ_RCPT_ENDPOINT     == request->bmRequestType_bit.recipient &&
+       TUSB_REQ_CLEAR_FEATURE     == request->bRequest                    &&
+       TUSB_REQ_FEATURE_EDPT_HALT == request->wValue )
+  {
+    uint8_t const ep_addr = tu_u16_low(request->wIndex);
+
+    if ( p_msc->stage == MSC_STAGE_NEED_RESET )
+    {
+      // reset recovery is required to recover from this stage
+      // Clear Stall request cannot resolve this -> continue to stall endpoint
+      usbd_edpt_stall(rhport, ep_addr);
+    }
+    else
+    {
+      if ( ep_addr == p_msc->ep_in )
+      {
+        if ( p_msc->stage == MSC_STAGE_STATUS )
+        {
+          // resume sending SCSI status if we are in this stage previously before stalled
+          TU_ASSERT( send_csw(rhport, p_msc) );
+        }
+      }
+      else if ( ep_addr == p_msc->ep_out )
+      {
+        if ( p_msc->stage == MSC_STAGE_CMD )
+        {
+          // part of reset recovery (probably due to invalid CBW) -> prepare for new command
+          // Note: skip if already queued previously
+          if ( usbd_edpt_ready(rhport, p_msc->ep_out) )
+          {
+            TU_ASSERT( prepare_cbw(rhport, p_msc) );
+          }
+        }
+      }
+    }
+
+    return true;
+  }
+
+  // From this point only handle class request only
+  TU_VERIFY(request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS);
+
+  switch ( request->bRequest )
+  {
+    case MSC_REQ_RESET:
+      TU_LOG(MSC_DEBUG, "  MSC BOT Reset\r\n");
+      TU_VERIFY(request->wValue == 0 && request->wLength == 0);
+
+      // driver state reset
+      proc_bot_reset(p_msc);
+
+      tud_control_status(rhport, request);
+    break;
+
+    case MSC_REQ_GET_MAX_LUN:
+    {
+      TU_LOG(MSC_DEBUG, "  MSC Get Max Lun\r\n");
+      TU_VERIFY(request->wValue == 0 && request->wLength == 1);
+
+      uint8_t maxlun = 1;
+      if (tud_msc_get_maxlun_cb) maxlun = tud_msc_get_maxlun_cb();
+      TU_VERIFY(maxlun);
+
+      // MAX LUN is minus 1 by specs
+      maxlun--;
+
+      tud_control_xfer(rhport, request, &maxlun, 1);
+    }
+    break;
+
+    default: return false; // stall unsupported request
+  }
+
+  return true;
+}
+
+bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes)
+{
+  (void) event;
+
+  mscd_interface_t* p_msc = &_mscd_itf;
+  msc_cbw_t const * p_cbw = &p_msc->cbw;
+  msc_csw_t       * p_csw = &p_msc->csw;
+
+  switch (p_msc->stage)
+  {
+    case MSC_STAGE_CMD:
+      //------------- new CBW received -------------//
+      // Complete IN while waiting for CMD is usually Status of previous SCSI op, ignore it
+      if(ep_addr != p_msc->ep_out) return true;
+
+      if ( !(xferred_bytes == sizeof(msc_cbw_t) && p_cbw->signature == MSC_CBW_SIGNATURE) )
+      {
+        TU_LOG(MSC_DEBUG, "  SCSI CBW is not valid\r\n");
+
+        // BOT 6.6.1 If CBW is not valid stall both endpoints until reset recovery
+        p_msc->stage = MSC_STAGE_NEED_RESET;
+
+        // invalid CBW stall both endpoints
+        usbd_edpt_stall(rhport, p_msc->ep_in);
+        usbd_edpt_stall(rhport, p_msc->ep_out);
+
+        return false;
+      }
+
+      TU_LOG(MSC_DEBUG, "  SCSI Command: %s\r\n", tu_lookup_find(&_msc_scsi_cmd_table, p_cbw->command[0]));
+      //TU_LOG_MEM(MSC_DEBUG, p_cbw, xferred_bytes, 2);
+
+      p_csw->signature    = MSC_CSW_SIGNATURE;
+      p_csw->tag          = p_cbw->tag;
+      p_csw->data_residue = 0;
+      p_csw->status       = MSC_CSW_STATUS_PASSED;
+
+      /*------------- Parse command and prepare DATA -------------*/
+      p_msc->stage = MSC_STAGE_DATA;
+      p_msc->total_len = p_cbw->total_bytes;
+      p_msc->xferred_len = 0;
+
+      // Read10 or Write10
+      if ( (SCSI_CMD_READ_10 == p_cbw->command[0]) || (SCSI_CMD_WRITE_10 == p_cbw->command[0]) )
+      {
+        uint8_t const status = rdwr10_validate_cmd(p_cbw);
+
+        if ( status != MSC_CSW_STATUS_PASSED)
+        {
+          fail_scsi_op(rhport, p_msc, status);
+        }else if ( p_cbw->total_bytes )
+        {
+          if (SCSI_CMD_READ_10 == p_cbw->command[0])
+          {
+            proc_read10_cmd(rhport, p_msc);
+          }else
+          {
+            proc_write10_cmd(rhport, p_msc);
+          }
+        }else
+        {
+          // no data transfer, only exist in complaint test suite
+          p_msc->stage = MSC_STAGE_STATUS;
+        }
+      }
+      else
+      {
+        // For other SCSI commands
+        // 1. OUT : queue transfer (invoke app callback after done)
+        // 2. IN & Zero: Process if is built-in, else Invoke app callback. Skip DATA if zero length
+        if ( (p_cbw->total_bytes > 0 ) && !is_data_in(p_cbw->dir) )
+        {
+          if (p_cbw->total_bytes > sizeof(_mscd_buf))
+          {
+            TU_LOG(MSC_DEBUG, "  SCSI reject non READ10/WRITE10 with large data\r\n");
+            fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+          }else
+          {
+            // Didn't check for case 9 (Ho > Dn), which requires examining scsi command first
+            // but it is OK to just receive data then responded with failed status
+            TU_ASSERT( usbd_edpt_xfer(rhport, p_msc->ep_out, _mscd_buf, p_msc->total_len) );
+          }
+        }else
+        {
+          // First process if it is a built-in commands
+          int32_t resplen = proc_builtin_scsi(p_cbw->lun, p_cbw->command, _mscd_buf, sizeof(_mscd_buf));
+
+          // Invoke user callback if not built-in
+          if ( (resplen < 0) && (p_msc->sense_key == 0) )
+          {
+            resplen = tud_msc_scsi_cb(p_cbw->lun, p_cbw->command, _mscd_buf, p_msc->total_len);
+          }
+
+          if ( resplen < 0 )
+          {
+            // unsupported command
+            TU_LOG(MSC_DEBUG, "  SCSI unsupported command\r\n");
+            fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+          }
+          else if (resplen == 0)
+          {
+            if (p_cbw->total_bytes)
+            {
+              // 6.7 The 13 Cases: case 4 (Hi > Dn)
+              // TU_LOG(MSC_DEBUG, "  SCSI case 4 (Hi > Dn): %lu\r\n", p_cbw->total_bytes);
+              fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+            }else
+            {
+              // case 1 Hn = Dn: all good
+              p_msc->stage = MSC_STAGE_STATUS;
+            }
+          }
+          else
+          {
+            if ( p_cbw->total_bytes == 0 )
+            {
+              // 6.7 The 13 Cases: case 2 (Hn < Di)
+              // TU_LOG(MSC_DEBUG, "  SCSI case 2 (Hn < Di): %lu\r\n", p_cbw->total_bytes);
+              fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+            }else
+            {
+              // cannot return more than host expect
+              p_msc->total_len = tu_min32((uint32_t) resplen, p_cbw->total_bytes);
+              TU_ASSERT( usbd_edpt_xfer(rhport, p_msc->ep_in, _mscd_buf, p_msc->total_len) );
+            }
+          }
+        }
+      }
+    break;
+
+    case MSC_STAGE_DATA:
+      TU_LOG(MSC_DEBUG, "  SCSI Data\r\n");
+      //TU_LOG_MEM(MSC_DEBUG, _mscd_buf, xferred_bytes, 2);
+
+      if (SCSI_CMD_READ_10 == p_cbw->command[0])
+      {
+        p_msc->xferred_len += xferred_bytes;
+
+        if ( p_msc->xferred_len >= p_msc->total_len )
+        {
+          // Data Stage is complete
+          p_msc->stage = MSC_STAGE_STATUS;
+        }else
+        {
+          proc_read10_cmd(rhport, p_msc);
+        }
+      }
+      else if (SCSI_CMD_WRITE_10 == p_cbw->command[0])
+      {
+        proc_write10_new_data(rhport, p_msc, xferred_bytes);
+      }
+      else
+      {
+        p_msc->xferred_len += xferred_bytes;
+
+        // OUT transfer, invoke callback if needed
+        if ( !is_data_in(p_cbw->dir) )
+        {
+          int32_t cb_result = tud_msc_scsi_cb(p_cbw->lun, p_cbw->command, _mscd_buf, p_msc->total_len);
+
+          if ( cb_result < 0 )
+          {
+            // unsupported command
+            TU_LOG(MSC_DEBUG, "  SCSI unsupported command\r\n");
+            fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+          }else
+          {
+            // TODO haven't implement this scenario any further yet
+          }
+        }
+
+        if ( p_msc->xferred_len >= p_msc->total_len )
+        {
+          // Data Stage is complete
+          p_msc->stage = MSC_STAGE_STATUS;
+        }
+        else
+        {
+          // This scenario with command that take more than one transfer is already rejected at Command stage
+          TU_BREAKPOINT();
+        }
+      }
+    break;
+
+    case MSC_STAGE_STATUS:
+      // processed immediately after this switch, supposedly to be empty
+    break;
+
+    case MSC_STAGE_STATUS_SENT:
+      // Wait for the Status phase to complete
+      if( (ep_addr == p_msc->ep_in) && (xferred_bytes == sizeof(msc_csw_t)) )
+      {
+        TU_LOG(MSC_DEBUG, "  SCSI Status = %u\r\n", p_csw->status);
+        // TU_LOG_MEM(MSC_DEBUG, p_csw, xferred_bytes, 2);
+
+        // Invoke complete callback if defined
+        // Note: There is racing issue with samd51 + qspi flash testing with arduino
+        // if complete_cb() is invoked after queuing the status.
+        switch(p_cbw->command[0])
+        {
+          case SCSI_CMD_READ_10:
+            if ( tud_msc_read10_complete_cb ) tud_msc_read10_complete_cb(p_cbw->lun);
+          break;
+
+          case SCSI_CMD_WRITE_10:
+            if ( tud_msc_write10_complete_cb ) tud_msc_write10_complete_cb(p_cbw->lun);
+          break;
+
+          default:
+            if ( tud_msc_scsi_complete_cb ) tud_msc_scsi_complete_cb(p_cbw->lun, p_cbw->command);
+          break;
+        }
+
+        TU_ASSERT( prepare_cbw(rhport, p_msc) );
+      }else
+      {
+        // Any xfer ended here is consider unknown error, ignore it
+        TU_LOG1("  Warning expect SCSI Status but received unknown data\r\n");
+      }
+    break;
+
+    default : break;
+  }
+
+  if ( p_msc->stage == MSC_STAGE_STATUS )
+  {
+    // skip status if epin is currently stalled, will do it when received Clear Stall request
+    if ( !usbd_edpt_stalled(rhport,  p_msc->ep_in) )
+    {
+      if ( (p_cbw->total_bytes > p_msc->xferred_len) && is_data_in(p_cbw->dir) )
+      {
+        // 6.7 The 13 Cases: case 5 (Hi > Di): STALL before status
+        // TU_LOG(MSC_DEBUG, "  SCSI case 5 (Hi > Di): %lu > %lu\r\n", p_cbw->total_bytes, p_msc->xferred_len);
+        usbd_edpt_stall(rhport, p_msc->ep_in);
+      }else
+      {
+        TU_ASSERT( send_csw(rhport, p_msc) );
+      }
+    }
+
+    #if TU_CHECK_MCU(OPT_MCU_CXD56)
+    // WORKAROUND: cxd56 has its own nuttx usb stack which does not forward Set/ClearFeature(Endpoint) to DCD.
+    // There is no way for us to know when EP is un-stall, therefore we will unconditionally un-stall here and
+    // hope everything will work
+    if ( usbd_edpt_stalled(rhport, p_msc->ep_in) )
+    {
+      usbd_edpt_clear_stall(rhport, p_msc->ep_in);
+      send_csw(rhport, p_msc);
+    }
+    #endif
+  }
+
+  return true;
+}
+
+/*------------------------------------------------------------------*/
+/* SCSI Command Process
+ *------------------------------------------------------------------*/
+
+// return response's length (copied to buffer). Negative if it is not an built-in command or indicate Failed status (CSW)
+// In case of a failed status, sense key must be set for reason of failure
+static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_t* buffer, uint32_t bufsize)
+{
+  (void) bufsize; // TODO refractor later
+  int32_t resplen;
+
+  mscd_interface_t* p_msc = &_mscd_itf;
+
+  switch ( scsi_cmd[0] )
+  {
+    case SCSI_CMD_TEST_UNIT_READY:
+      resplen = 0;
+      if ( !tud_msc_test_unit_ready_cb(lun) )
+      {
+        // Failed status response
+        resplen = - 1;
+
+        // If sense key is not set by callback, default to Logical Unit Not Ready, Cause Not Reportable
+        if ( p_msc->sense_key == 0 ) tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x04, 0x00);
+      }
+    break;
+
+    case SCSI_CMD_START_STOP_UNIT:
+      resplen = 0;
+
+      if (tud_msc_start_stop_cb)
+      {
+        scsi_start_stop_unit_t const * start_stop = (scsi_start_stop_unit_t const *) scsi_cmd;
+        if ( !tud_msc_start_stop_cb(lun, start_stop->power_condition, start_stop->start, start_stop->load_eject) )
+        {
+          // Failed status response
+          resplen = - 1;
+
+          // If sense key is not set by callback, default to Logical Unit Not Ready, Cause Not Reportable
+          if ( p_msc->sense_key == 0 ) tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x04, 0x00);
+        }
+      }
+    break;
+
+    case SCSI_CMD_READ_CAPACITY_10:
+    {
+      uint32_t block_count;
+      uint32_t block_size;
+      uint16_t block_size_u16;
+
+      tud_msc_capacity_cb(lun, &block_count, &block_size_u16);
+      block_size = (uint32_t) block_size_u16;
+
+      // Invalid block size/count from callback, possibly unit is not ready
+      // stall this request, set sense key to NOT READY
+      if (block_count == 0 || block_size == 0)
+      {
+        resplen = -1;
+
+        // If sense key is not set by callback, default to Logical Unit Not Ready, Cause Not Reportable
+        if ( p_msc->sense_key == 0 ) tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x04, 0x00);
+      }else
+      {
+        scsi_read_capacity10_resp_t read_capa10;
+
+        read_capa10.last_lba = tu_htonl(block_count-1);
+        read_capa10.block_size = tu_htonl(block_size);
+
+        resplen = sizeof(read_capa10);
+        memcpy(buffer, &read_capa10, resplen);
+      }
+    }
+    break;
+
+    case SCSI_CMD_READ_FORMAT_CAPACITY:
+    {
+      scsi_read_format_capacity_data_t read_fmt_capa =
+      {
+          .list_length     = 8,
+          .block_num       = 0,
+          .descriptor_type = 2, // formatted media
+          .block_size_u16  = 0
+      };
+
+      uint32_t block_count;
+      uint16_t block_size;
+
+      tud_msc_capacity_cb(lun, &block_count, &block_size);
+
+      // Invalid block size/count from callback, possibly unit is not ready
+      // stall this request, set sense key to NOT READY
+      if (block_count == 0 || block_size == 0)
+      {
+        resplen = -1;
+
+        // If sense key is not set by callback, default to Logical Unit Not Ready, Cause Not Reportable
+        if ( p_msc->sense_key == 0 ) tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x04, 0x00);
+      }else
+      {
+        read_fmt_capa.block_num = tu_htonl(block_count);
+        read_fmt_capa.block_size_u16 = tu_htons(block_size);
+
+        resplen = sizeof(read_fmt_capa);
+        memcpy(buffer, &read_fmt_capa, resplen);
+      }
+    }
+    break;
+
+    case SCSI_CMD_INQUIRY:
+    {
+      scsi_inquiry_resp_t inquiry_rsp =
+      {
+          .is_removable         = 1,
+          .version              = 2,
+          .response_data_format = 2,
+      };
+
+      // vendor_id, product_id, product_rev is space padded string
+      memset(inquiry_rsp.vendor_id  , ' ', sizeof(inquiry_rsp.vendor_id));
+      memset(inquiry_rsp.product_id , ' ', sizeof(inquiry_rsp.product_id));
+      memset(inquiry_rsp.product_rev, ' ', sizeof(inquiry_rsp.product_rev));
+
+      tud_msc_inquiry_cb(lun, inquiry_rsp.vendor_id, inquiry_rsp.product_id, inquiry_rsp.product_rev);
+
+      resplen = sizeof(inquiry_rsp);
+      memcpy(buffer, &inquiry_rsp, resplen);
+    }
+    break;
+
+    case SCSI_CMD_MODE_SENSE_6:
+    {
+      scsi_mode_sense6_resp_t mode_resp =
+      {
+          .data_len = 3,
+          .medium_type = 0,
+          .write_protected = false,
+          .reserved = 0,
+          .block_descriptor_len = 0  // no block descriptor are included
+      };
+
+      bool writable = true;
+      if ( tud_msc_is_writable_cb )
+      {
+        writable = tud_msc_is_writable_cb(lun);
+      }
+
+      mode_resp.write_protected = !writable;
+
+      resplen = sizeof(mode_resp);
+      memcpy(buffer, &mode_resp, resplen);
+    }
+    break;
+
+    case SCSI_CMD_REQUEST_SENSE:
+    {
+      scsi_sense_fixed_resp_t sense_rsp =
+      {
+          .response_code = 0x70,
+          .valid         = 1
+      };
+
+      sense_rsp.add_sense_len = sizeof(scsi_sense_fixed_resp_t) - 8;
+
+      sense_rsp.sense_key           = p_msc->sense_key;
+      sense_rsp.add_sense_code      = p_msc->add_sense_code;
+      sense_rsp.add_sense_qualifier = p_msc->add_sense_qualifier;
+
+      resplen = sizeof(sense_rsp);
+      memcpy(buffer, &sense_rsp, resplen);
+
+      // Clear sense data after copy
+      tud_msc_set_sense(lun, 0, 0, 0);
+    }
+    break;
+
+    default: resplen = -1; break;
+  }
+
+  return resplen;
+}
+
+static void proc_read10_cmd(uint8_t rhport, mscd_interface_t* p_msc)
+{
+  msc_cbw_t const * p_cbw = &p_msc->cbw;
+
+  // block size already verified not zero
+  uint16_t const block_sz = rdwr10_get_blocksize(p_cbw);
+
+  // Adjust lba with transferred bytes
+  uint32_t const lba = rdwr10_get_lba(p_cbw->command) + (p_msc->xferred_len / block_sz);
+
+  // remaining bytes capped at class buffer
+  int32_t nbytes = (int32_t) tu_min32(sizeof(_mscd_buf), p_cbw->total_bytes-p_msc->xferred_len);
+
+  // Application can consume smaller bytes
+  uint32_t const offset = p_msc->xferred_len % block_sz;
+  nbytes = tud_msc_read10_cb(p_cbw->lun, lba, offset, _mscd_buf, (uint32_t) nbytes);
+
+  if ( nbytes < 0 )
+  {
+    // negative means error -> endpoint is stalled & status in CSW set to failed
+    TU_LOG(MSC_DEBUG, "  tud_msc_read10_cb() return -1\r\n");
+
+    // Sense = Flash not ready for access
+    tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_MEDIUM_ERROR, 0x33, 0x00);
+
+    fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+  }
+  else if ( nbytes == 0 )
+  {
+    // zero means not ready -> simulate an transfer complete so that this driver callback will fired again
+    dcd_event_xfer_complete(rhport, p_msc->ep_in, 0, XFER_RESULT_SUCCESS, false);
+  }
+  else
+  {
+    TU_ASSERT( usbd_edpt_xfer(rhport, p_msc->ep_in, _mscd_buf, nbytes), );
+  }
+}
+
+static void proc_write10_cmd(uint8_t rhport, mscd_interface_t* p_msc)
+{
+  msc_cbw_t const * p_cbw = &p_msc->cbw;
+  bool writable = true;
+
+  if ( tud_msc_is_writable_cb )
+  {
+    writable = tud_msc_is_writable_cb(p_cbw->lun);
+  }
+
+  if ( !writable )
+  {
+    // Not writable, complete this SCSI op with error
+    // Sense = Write protected
+    tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_DATA_PROTECT, 0x27, 0x00);
+    fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+    return;
+  }
+
+  // remaining bytes capped at class buffer
+  int32_t nbytes = (int32_t) tu_min32(sizeof(_mscd_buf), p_cbw->total_bytes-p_msc->xferred_len);
+
+  // Write10 callback will be called later when usb transfer complete
+  TU_ASSERT( usbd_edpt_xfer(rhport, p_msc->ep_out, _mscd_buf, nbytes), );
+}
+
+// process new data arrived from WRITE10
+static void proc_write10_new_data(uint8_t rhport, mscd_interface_t* p_msc, uint32_t xferred_bytes)
+{
+  msc_cbw_t const * p_cbw = &p_msc->cbw;
+
+  // block size already verified not zero
+  uint16_t const block_sz = rdwr10_get_blocksize(p_cbw);
+
+  // Adjust lba with transferred bytes
+  uint32_t const lba = rdwr10_get_lba(p_cbw->command) + (p_msc->xferred_len / block_sz);
+
+  // Invoke callback to consume new data
+  uint32_t const offset = p_msc->xferred_len % block_sz;
+  int32_t nbytes = tud_msc_write10_cb(p_cbw->lun, lba, offset, _mscd_buf, xferred_bytes);
+
+  if ( nbytes < 0 )
+  {
+    // negative means error -> failed this scsi op
+    TU_LOG(MSC_DEBUG, "  tud_msc_write10_cb() return -1\r\n");
+
+    // update actual byte before failed
+    p_msc->xferred_len += xferred_bytes;
+
+    // Sense = Flash not ready for access
+    tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_MEDIUM_ERROR, 0x33, 0x00);
+
+    fail_scsi_op(rhport, p_msc, MSC_CSW_STATUS_FAILED);
+  }else
+  {
+    // Application consume less than what we got (including zero)
+    if ( (uint32_t) nbytes < xferred_bytes )
+    {
+      if ( nbytes > 0 )
+      {
+        p_msc->xferred_len += nbytes;
+        memmove(_mscd_buf, _mscd_buf+nbytes, xferred_bytes-nbytes);
+      }
+
+      // simulate an transfer complete with adjusted parameters --> callback will be invoked with adjusted parameter
+      dcd_event_xfer_complete(rhport, p_msc->ep_out, xferred_bytes-nbytes, XFER_RESULT_SUCCESS, false);
+    }
+    else
+    {
+      // Application consume all bytes in our buffer
+      p_msc->xferred_len += xferred_bytes;
+
+      if ( p_msc->xferred_len >= p_msc->total_len )
+      {
+        // Data Stage is complete
+        p_msc->stage = MSC_STAGE_STATUS;
+      }else
+      {
+        // prepare to receive more data from host
+        proc_write10_cmd(rhport, p_msc);
+      }
+    }
+  }
+}
+
+#endif
diff --git a/src/class/msc/msc_device.h b/src/class/msc/msc_device.h
new file mode 100644
index 0000000..d326943
--- /dev/null
+++ b/src/class/msc/msc_device.h
@@ -0,0 +1,159 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#ifndef _TUSB_MSC_DEVICE_H_
+#define _TUSB_MSC_DEVICE_H_
+
+#include "common/tusb_common.h"
+#include "msc.h"
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+//--------------------------------------------------------------------+
+// Class Driver Configuration
+//--------------------------------------------------------------------+
+
+#if !defined(CFG_TUD_MSC_EP_BUFSIZE) & defined(CFG_TUD_MSC_BUFSIZE)
+  // TODO warn user to use new name later on
+  // #warning CFG_TUD_MSC_BUFSIZE is renamed to CFG_TUD_MSC_EP_BUFSIZE, please update to use the new name
+  #define CFG_TUD_MSC_EP_BUFSIZE  CFG_TUD_MSC_BUFSIZE
+#endif
+
+#ifndef CFG_TUD_MSC_EP_BUFSIZE
+  #error CFG_TUD_MSC_EP_BUFSIZE must be defined, value of a block size should work well, the more the better
+#endif
+
+TU_VERIFY_STATIC(CFG_TUD_MSC_EP_BUFSIZE < UINT16_MAX, "Size is not correct");
+
+//--------------------------------------------------------------------+
+// Application API
+//--------------------------------------------------------------------+
+
+// Set SCSI sense response
+bool tud_msc_set_sense(uint8_t lun, uint8_t sense_key, uint8_t add_sense_code, uint8_t add_sense_qualifier);
+
+//--------------------------------------------------------------------+
+// Application Callbacks (WEAK is optional)
+//--------------------------------------------------------------------+
+
+// Invoked when received SCSI READ10 command
+// - Address = lba * BLOCK_SIZE + offset
+//   - offset is only needed if CFG_TUD_MSC_EP_BUFSIZE is smaller than BLOCK_SIZE.
+//
+// - Application fill the buffer (up to bufsize) with address contents and return number of read byte. If
+//   - read < bufsize : These bytes are transferred first and callback invoked again for remaining data.
+//
+//   - read == 0      : Indicate application is not ready yet e.g disk I/O busy.
+//                      Callback invoked again with the same parameters later on.
+//
+//   - read < 0       : Indicate application error e.g invalid address. This request will be STALLed
+//                      and return failed status in command status wrapper phase.
+int32_t tud_msc_read10_cb (uint8_t lun, uint32_t lba, uint32_t offset, void* buffer, uint32_t bufsize);
+
+// Invoked when received SCSI WRITE10 command
+// - Address = lba * BLOCK_SIZE + offset
+//   - offset is only needed if CFG_TUD_MSC_EP_BUFSIZE is smaller than BLOCK_SIZE.
+//
+// - Application write data from buffer to address contents (up to bufsize) and return number of written byte. If
+//   - write < bufsize : callback invoked again with remaining data later on.
+//
+//   - write == 0      : Indicate application is not ready yet e.g disk I/O busy.
+//                       Callback invoked again with the same parameters later on.
+//
+//   - write < 0       : Indicate application error e.g invalid address. This request will be STALLed
+//                       and return failed status in command status wrapper phase.
+//
+// TODO change buffer to const uint8_t*
+int32_t tud_msc_write10_cb (uint8_t lun, uint32_t lba, uint32_t offset, uint8_t* buffer, uint32_t bufsize);
+
+// Invoked when received SCSI_CMD_INQUIRY
+// Application fill vendor id, product id and revision with string up to 8, 16, 4 characters respectively
+void tud_msc_inquiry_cb(uint8_t lun, uint8_t vendor_id[8], uint8_t product_id[16], uint8_t product_rev[4]);
+
+// Invoked when received Test Unit Ready command.
+// return true allowing host to read/write this LUN e.g SD card inserted
+bool tud_msc_test_unit_ready_cb(uint8_t lun);
+
+// Invoked when received SCSI_CMD_READ_CAPACITY_10 and SCSI_CMD_READ_FORMAT_CAPACITY to determine the disk size
+// Application update block count and block size
+void tud_msc_capacity_cb(uint8_t lun, uint32_t* block_count, uint16_t* block_size);
+
+/**
+ * Invoked when received an SCSI command not in built-in list below.
+ * - READ_CAPACITY10, READ_FORMAT_CAPACITY, INQUIRY, TEST_UNIT_READY, START_STOP_UNIT, MODE_SENSE6, REQUEST_SENSE
+ * - READ10 and WRITE10 has their own callbacks
+ *
+ * \param[in]   lun         Logical unit number
+ * \param[in]   scsi_cmd    SCSI command contents which application must examine to response accordingly
+ * \param[out]  buffer      Buffer for SCSI Data Stage.
+ *                            - For INPUT: application must fill this with response.
+ *                            - For OUTPUT it holds the Data from host
+ * \param[in]   bufsize     Buffer's length.
+ *
+ * \return      Actual bytes processed, can be zero for no-data command.
+ * \retval      negative    Indicate error e.g unsupported command, tinyusb will \b STALL the corresponding
+ *                          endpoint and return failed status in command status wrapper phase.
+ */
+int32_t tud_msc_scsi_cb (uint8_t lun, uint8_t const scsi_cmd[16], void* buffer, uint16_t bufsize);
+
+/*------------- Optional callbacks -------------*/
+
+// Invoked when received GET_MAX_LUN request, required for multiple LUNs implementation
+TU_ATTR_WEAK uint8_t tud_msc_get_maxlun_cb(void);
+
+// Invoked when received Start Stop Unit command
+// - Start = 0 : stopped power mode, if load_eject = 1 : unload disk storage
+// - Start = 1 : active mode, if load_eject = 1 : load disk storage
+TU_ATTR_WEAK bool tud_msc_start_stop_cb(uint8_t lun, uint8_t power_condition, bool start, bool load_eject);
+
+// Invoked when Read10 command is complete
+TU_ATTR_WEAK void tud_msc_read10_complete_cb(uint8_t lun);
+
+// Invoke when Write10 command is complete, can be used to flush flash caching
+TU_ATTR_WEAK void tud_msc_write10_complete_cb(uint8_t lun);
+
+// Invoked when command in tud_msc_scsi_cb is complete
+TU_ATTR_WEAK void tud_msc_scsi_complete_cb(uint8_t lun, uint8_t const scsi_cmd[16]);
+
+// Invoked to check if device is writable as part of SCSI WRITE10
+TU_ATTR_WEAK bool tud_msc_is_writable_cb(uint8_t lun);
+
+//--------------------------------------------------------------------+
+// Internal Class Driver API
+//--------------------------------------------------------------------+
+void     mscd_init            (void);
+void     mscd_reset           (uint8_t rhport);
+uint16_t mscd_open            (uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len);
+bool     mscd_control_xfer_cb (uint8_t rhport, uint8_t stage, tusb_control_request_t const * p_request);
+bool     mscd_xfer_cb         (uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* _TUSB_MSC_DEVICE_H_ */
diff --git a/src/class/msc/msc_host.c b/src/class/msc/msc_host.c
new file mode 100644
index 0000000..fa65199
--- /dev/null
+++ b/src/class/msc/msc_host.c
@@ -0,0 +1,491 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "tusb_option.h"
+
+#if TUSB_OPT_HOST_ENABLED & CFG_TUH_MSC
+
+#include "host/usbh.h"
+#include "host/usbh_classdriver.h"
+
+#include "msc_host.h"
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF
+//--------------------------------------------------------------------+
+enum
+{
+  MSC_STAGE_IDLE = 0,
+  MSC_STAGE_CMD,
+  MSC_STAGE_DATA,
+  MSC_STAGE_STATUS,
+};
+
+typedef struct
+{
+  uint8_t itf_num;
+  uint8_t ep_in;
+  uint8_t ep_out;
+
+  uint8_t max_lun;
+
+  volatile bool configured; // Receive SET_CONFIGURE
+  volatile bool mounted;    // Enumeration is complete
+
+  struct {
+    uint32_t block_size;
+    uint32_t block_count;
+  } capacity[CFG_TUH_MSC_MAXLUN];
+
+  //------------- SCSI -------------//
+  uint8_t stage;
+  void*   buffer;
+  tuh_msc_complete_cb_t complete_cb;
+
+  msc_cbw_t cbw;
+  msc_csw_t csw;
+}msch_interface_t;
+
+CFG_TUSB_MEM_SECTION static msch_interface_t _msch_itf[CFG_TUH_DEVICE_MAX];
+
+// buffer used to read scsi information when mounted
+// largest response data currently is inquiry TODO Inquiry is not part of enum anymore
+CFG_TUSB_MEM_SECTION TU_ATTR_ALIGNED(4)
+static uint8_t _msch_buffer[sizeof(scsi_inquiry_resp_t)];
+
+TU_ATTR_ALWAYS_INLINE
+static inline msch_interface_t* get_itf(uint8_t dev_addr)
+{
+  return &_msch_itf[dev_addr-1];
+}
+
+//--------------------------------------------------------------------+
+// PUBLIC API
+//--------------------------------------------------------------------+
+uint8_t tuh_msc_get_maxlun(uint8_t dev_addr)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  return p_msc->max_lun;
+}
+
+uint32_t tuh_msc_get_block_count(uint8_t dev_addr, uint8_t lun)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  return p_msc->capacity[lun].block_count;
+}
+
+uint32_t tuh_msc_get_block_size(uint8_t dev_addr, uint8_t lun)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  return p_msc->capacity[lun].block_size;
+}
+
+bool tuh_msc_mounted(uint8_t dev_addr)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  return p_msc->mounted;
+}
+
+bool tuh_msc_ready(uint8_t dev_addr)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  return p_msc->mounted && !usbh_edpt_busy(dev_addr, p_msc->ep_in);
+}
+
+//--------------------------------------------------------------------+
+// PUBLIC API: SCSI COMMAND
+//--------------------------------------------------------------------+
+static inline void cbw_init(msc_cbw_t *cbw, uint8_t lun)
+{
+  tu_memclr(cbw, sizeof(msc_cbw_t));
+  cbw->signature = MSC_CBW_SIGNATURE;
+  cbw->tag       = 0x54555342; // TUSB
+  cbw->lun       = lun;
+}
+
+bool tuh_msc_scsi_command(uint8_t dev_addr, msc_cbw_t const* cbw, void* data, tuh_msc_complete_cb_t complete_cb)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  TU_VERIFY(p_msc->configured);
+
+  // TODO claim endpoint
+
+  p_msc->cbw = *cbw;
+  p_msc->stage = MSC_STAGE_CMD;
+  p_msc->buffer = data;
+  p_msc->complete_cb = complete_cb;
+
+  TU_ASSERT(usbh_edpt_xfer(dev_addr, p_msc->ep_out, (uint8_t*) &p_msc->cbw, sizeof(msc_cbw_t)));
+
+  return true;
+}
+
+bool tuh_msc_read_capacity(uint8_t dev_addr, uint8_t lun, scsi_read_capacity10_resp_t* response, tuh_msc_complete_cb_t complete_cb)
+{
+   msch_interface_t* p_msc = get_itf(dev_addr);
+   TU_VERIFY(p_msc->configured);
+
+  msc_cbw_t cbw;
+  cbw_init(&cbw, lun);
+
+  cbw.total_bytes = sizeof(scsi_read_capacity10_resp_t);
+  cbw.dir        = TUSB_DIR_IN_MASK;
+  cbw.cmd_len    = sizeof(scsi_read_capacity10_t);
+  cbw.command[0] = SCSI_CMD_READ_CAPACITY_10;
+
+  return tuh_msc_scsi_command(dev_addr, &cbw, response, complete_cb);
+}
+
+bool tuh_msc_inquiry(uint8_t dev_addr, uint8_t lun, scsi_inquiry_resp_t* response, tuh_msc_complete_cb_t complete_cb)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  TU_VERIFY(p_msc->mounted);
+
+  msc_cbw_t cbw;
+  cbw_init(&cbw, lun);
+
+  cbw.total_bytes = sizeof(scsi_inquiry_resp_t);
+  cbw.dir         = TUSB_DIR_IN_MASK;
+  cbw.cmd_len     = sizeof(scsi_inquiry_t);
+
+  scsi_inquiry_t const cmd_inquiry =
+  {
+    .cmd_code     = SCSI_CMD_INQUIRY,
+    .alloc_length = sizeof(scsi_inquiry_resp_t)
+  };
+  memcpy(cbw.command, &cmd_inquiry, cbw.cmd_len);
+
+  return tuh_msc_scsi_command(dev_addr, &cbw, response, complete_cb);
+}
+
+bool tuh_msc_test_unit_ready(uint8_t dev_addr, uint8_t lun, tuh_msc_complete_cb_t complete_cb)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  TU_VERIFY(p_msc->configured);
+
+  msc_cbw_t cbw;
+  cbw_init(&cbw, lun);
+
+  cbw.total_bytes = 0;
+  cbw.dir         = TUSB_DIR_OUT;
+  cbw.cmd_len     = sizeof(scsi_test_unit_ready_t);
+  cbw.command[0]  = SCSI_CMD_TEST_UNIT_READY;
+  cbw.command[1]  = lun; // according to wiki TODO need verification
+
+  return tuh_msc_scsi_command(dev_addr, &cbw, NULL, complete_cb);
+}
+
+bool tuh_msc_request_sense(uint8_t dev_addr, uint8_t lun, void *resposne, tuh_msc_complete_cb_t complete_cb)
+{
+  msc_cbw_t cbw;
+  cbw_init(&cbw, lun);
+
+  cbw.total_bytes = 18; // TODO sense response
+  cbw.dir         = TUSB_DIR_IN_MASK;
+  cbw.cmd_len     = sizeof(scsi_request_sense_t);
+
+  scsi_request_sense_t const cmd_request_sense =
+  {
+    .cmd_code     = SCSI_CMD_REQUEST_SENSE,
+    .alloc_length = 18
+  };
+
+  memcpy(cbw.command, &cmd_request_sense, cbw.cmd_len);
+
+  return tuh_msc_scsi_command(dev_addr, &cbw, resposne, complete_cb);
+}
+
+bool tuh_msc_read10(uint8_t dev_addr, uint8_t lun, void * buffer, uint32_t lba, uint16_t block_count, tuh_msc_complete_cb_t complete_cb)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  TU_VERIFY(p_msc->mounted);
+
+  msc_cbw_t cbw;
+  cbw_init(&cbw, lun);
+ 
+  cbw.total_bytes = block_count*p_msc->capacity[lun].block_size;
+  cbw.dir         = TUSB_DIR_IN_MASK;
+  cbw.cmd_len     = sizeof(scsi_read10_t);
+ 
+  scsi_read10_t const cmd_read10 =
+  {
+    .cmd_code    = SCSI_CMD_READ_10,
+    .lba         = tu_htonl(lba),
+    .block_count = tu_htons(block_count)
+  };
+ 
+  memcpy(cbw.command, &cmd_read10, cbw.cmd_len);
+ 
+  return tuh_msc_scsi_command(dev_addr, &cbw, buffer, complete_cb);
+}
+ 
+bool tuh_msc_write10(uint8_t dev_addr, uint8_t lun, void const * buffer, uint32_t lba, uint16_t block_count, tuh_msc_complete_cb_t complete_cb)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  TU_VERIFY(p_msc->mounted);
+
+  msc_cbw_t cbw;
+  cbw_init(&cbw, lun);
+
+  cbw.total_bytes = block_count*p_msc->capacity[lun].block_size;
+  cbw.dir         = TUSB_DIR_OUT;
+  cbw.cmd_len     = sizeof(scsi_write10_t);
+
+  scsi_write10_t const cmd_write10 =
+  {
+    .cmd_code    = SCSI_CMD_WRITE_10,
+    .lba         = tu_htonl(lba),
+    .block_count = tu_htons(block_count)
+  };
+
+  memcpy(cbw.command, &cmd_write10, cbw.cmd_len);
+
+  return tuh_msc_scsi_command(dev_addr, &cbw, (void*)(uintptr_t) buffer, complete_cb);
+}
+
+#if 0
+// MSC interface Reset (not used now)
+bool tuh_msc_reset(uint8_t dev_addr)
+{
+  tusb_control_request_t const new_request =
+  {
+    .bmRequestType_bit =
+    {
+      .recipient = TUSB_REQ_RCPT_INTERFACE,
+      .type      = TUSB_REQ_TYPE_CLASS,
+      .direction = TUSB_DIR_OUT
+    },
+    .bRequest = MSC_REQ_RESET,
+    .wValue   = 0,
+    .wIndex   = p_msc->itf_num,
+    .wLength  = 0
+  };
+  TU_ASSERT( usbh_control_xfer( dev_addr, &new_request, NULL ) );
+}
+#endif
+
+//--------------------------------------------------------------------+
+// CLASS-USBH API
+//--------------------------------------------------------------------+
+void msch_init(void)
+{
+  tu_memclr(_msch_itf, sizeof(_msch_itf));
+}
+
+void msch_close(uint8_t dev_addr)
+{
+  TU_VERIFY(dev_addr <= CFG_TUH_DEVICE_MAX, );
+
+  msch_interface_t* p_msc = get_itf(dev_addr);
+
+  // invoke Application Callback
+  if (p_msc->mounted && tuh_msc_umount_cb) tuh_msc_umount_cb(dev_addr);
+
+  tu_memclr(p_msc, sizeof(msch_interface_t));
+}
+
+bool msch_xfer_cb(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  msc_cbw_t const * cbw = &p_msc->cbw;
+  msc_csw_t       * csw = &p_msc->csw;
+
+  switch (p_msc->stage)
+  {
+    case MSC_STAGE_CMD:
+      // Must be Command Block
+      TU_ASSERT(ep_addr == p_msc->ep_out &&  event == XFER_RESULT_SUCCESS && xferred_bytes == sizeof(msc_cbw_t));
+
+      if ( cbw->total_bytes && p_msc->buffer )
+      {
+        // Data stage if any
+        p_msc->stage = MSC_STAGE_DATA;
+
+        uint8_t const ep_data = (cbw->dir & TUSB_DIR_IN_MASK) ? p_msc->ep_in : p_msc->ep_out;
+        TU_ASSERT(usbh_edpt_xfer(dev_addr, ep_data, p_msc->buffer, cbw->total_bytes));
+      }else
+      {
+        // Status stage
+        p_msc->stage = MSC_STAGE_STATUS;
+        TU_ASSERT(usbh_edpt_xfer(dev_addr, p_msc->ep_in, (uint8_t*) &p_msc->csw, sizeof(msc_csw_t)));
+      }
+    break;
+
+    case MSC_STAGE_DATA:
+      // Status stage
+      p_msc->stage = MSC_STAGE_STATUS;
+      TU_ASSERT(usbh_edpt_xfer(dev_addr, p_msc->ep_in, (uint8_t*) &p_msc->csw, sizeof(msc_csw_t)));
+    break;
+
+    case MSC_STAGE_STATUS:
+      // SCSI op is complete
+      p_msc->stage = MSC_STAGE_IDLE;
+
+      if (p_msc->complete_cb) p_msc->complete_cb(dev_addr, cbw, csw);
+    break;
+
+    // unknown state
+    default: break;
+  }
+
+  return true;
+}
+
+//--------------------------------------------------------------------+
+// MSC Enumeration
+//--------------------------------------------------------------------+
+
+static bool config_get_maxlun_complete (uint8_t dev_addr, tusb_control_request_t const * request, xfer_result_t result);
+static bool config_test_unit_ready_complete(uint8_t dev_addr, msc_cbw_t const* cbw, msc_csw_t const* csw);
+static bool config_request_sense_complete(uint8_t dev_addr, msc_cbw_t const* cbw, msc_csw_t const* csw);
+static bool config_read_capacity_complete(uint8_t dev_addr, msc_cbw_t const* cbw, msc_csw_t const* csw);
+
+bool msch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *desc_itf, uint16_t max_len)
+{
+  TU_VERIFY (MSC_SUBCLASS_SCSI == desc_itf->bInterfaceSubClass &&
+             MSC_PROTOCOL_BOT  == desc_itf->bInterfaceProtocol);
+
+  // msc driver length is fixed
+  uint16_t const drv_len = sizeof(tusb_desc_interface_t) + desc_itf->bNumEndpoints*sizeof(tusb_desc_endpoint_t);
+  TU_ASSERT(drv_len <= max_len);
+
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  tusb_desc_endpoint_t const * ep_desc = (tusb_desc_endpoint_t const *) tu_desc_next(desc_itf);
+
+  for(uint32_t i=0; i<2; i++)
+  {
+    TU_ASSERT(TUSB_DESC_ENDPOINT == ep_desc->bDescriptorType && TUSB_XFER_BULK == ep_desc->bmAttributes.xfer);
+    TU_ASSERT(usbh_edpt_open(rhport, dev_addr, ep_desc));
+
+    if ( tu_edpt_dir(ep_desc->bEndpointAddress) == TUSB_DIR_IN )
+    {
+      p_msc->ep_in = ep_desc->bEndpointAddress;
+    }else
+    {
+      p_msc->ep_out = ep_desc->bEndpointAddress;
+    }
+
+    ep_desc = (tusb_desc_endpoint_t const *) tu_desc_next(ep_desc);
+  }
+
+  p_msc->itf_num = desc_itf->bInterfaceNumber;
+
+  return true;
+}
+
+bool msch_set_config(uint8_t dev_addr, uint8_t itf_num)
+{
+  msch_interface_t* p_msc = get_itf(dev_addr);
+  TU_ASSERT(p_msc->itf_num == itf_num);
+
+  p_msc->configured = true;
+
+  //------------- Get Max Lun -------------//
+  TU_LOG2("MSC Get Max Lun\r\n");
+  tusb_control_request_t request =
+  {
+    .bmRequestType_bit =
+    {
+      .recipient = TUSB_REQ_RCPT_INTERFACE,
+      .type      = TUSB_REQ_TYPE_CLASS,
+      .direction = TUSB_DIR_IN
+    },
+    .bRequest = MSC_REQ_GET_MAX_LUN,
+    .wValue   = 0,
+    .wIndex   = itf_num,
+    .wLength  = 1
+  };
+  TU_ASSERT(tuh_control_xfer(dev_addr, &request, &p_msc->max_lun, config_get_maxlun_complete));
+
+  return true;
+}
+
+static bool config_get_maxlun_complete (uint8_t dev_addr, tusb_control_request_t const * request, xfer_result_t result)
+{
+  (void) request;
+
+  msch_interface_t* p_msc = get_itf(dev_addr);
+
+  // STALL means zero
+  p_msc->max_lun = (XFER_RESULT_SUCCESS == result) ? _msch_buffer[0] : 0;
+  p_msc->max_lun++; // MAX LUN is minus 1 by specs
+
+  // TODO multiple LUN support
+  TU_LOG2("SCSI Test Unit Ready\r\n");
+  uint8_t const lun = 0;
+  tuh_msc_test_unit_ready(dev_addr, lun, config_test_unit_ready_complete);
+
+  return true;
+}
+
+static bool config_test_unit_ready_complete(uint8_t dev_addr, msc_cbw_t const* cbw, msc_csw_t const* csw)
+{
+  if (csw->status == 0)
+  {
+    // Unit is ready, read its capacity
+    TU_LOG2("SCSI Read Capacity\r\n");
+    tuh_msc_read_capacity(dev_addr, cbw->lun, (scsi_read_capacity10_resp_t*) ((void*) _msch_buffer), config_read_capacity_complete);
+  }else
+  {
+    // Note: During enumeration, some device fails Test Unit Ready and require a few retries
+    // with Request Sense to start working !!
+    // TODO limit number of retries
+    TU_LOG2("SCSI Request Sense\r\n");
+    TU_ASSERT(tuh_msc_request_sense(dev_addr, cbw->lun, _msch_buffer, config_request_sense_complete));
+  }
+
+  return true;
+}
+
+static bool config_request_sense_complete(uint8_t dev_addr, msc_cbw_t const* cbw, msc_csw_t const* csw)
+{
+  TU_ASSERT(csw->status == 0);
+  TU_ASSERT(tuh_msc_test_unit_ready(dev_addr, cbw->lun, config_test_unit_ready_complete));
+  return true;
+}
+
+static bool config_read_capacity_complete(uint8_t dev_addr, msc_cbw_t const* cbw, msc_csw_t const* csw)
+{
+  TU_ASSERT(csw->status == 0);
+
+  msch_interface_t* p_msc = get_itf(dev_addr);
+
+  // Capacity response field: Block size and Last LBA are both Big-Endian
+  scsi_read_capacity10_resp_t* resp = (scsi_read_capacity10_resp_t*) ((void*) _msch_buffer);
+  p_msc->capacity[cbw->lun].block_count = tu_ntohl(resp->last_lba) + 1;
+  p_msc->capacity[cbw->lun].block_size = tu_ntohl(resp->block_size);
+
+  // Mark enumeration is complete
+  p_msc->mounted = true;
+  if (tuh_msc_mount_cb) tuh_msc_mount_cb(dev_addr);
+
+  // notify usbh that driver enumeration is complete
+  usbh_driver_set_config_complete(dev_addr, p_msc->itf_num);
+
+  return true;
+}
+
+#endif
diff --git a/src/class/msc/msc_host.h b/src/class/msc/msc_host.h
new file mode 100644
index 0000000..7718ad4
--- /dev/null
+++ b/src/class/msc/msc_host.h
@@ -0,0 +1,119 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#ifndef _TUSB_MSC_HOST_H_
+#define _TUSB_MSC_HOST_H_
+
+#include "msc.h"
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+//--------------------------------------------------------------------+
+// Class Driver Configuration
+//--------------------------------------------------------------------+
+
+#ifndef CFG_TUH_MSC_MAXLUN
+#define CFG_TUH_MSC_MAXLUN  4
+#endif
+
+typedef bool (*tuh_msc_complete_cb_t)(uint8_t dev_addr, msc_cbw_t const* cbw, msc_csw_t const* csw);
+
+//--------------------------------------------------------------------+
+// Application API
+//--------------------------------------------------------------------+
+
+// Check if device supports MassStorage interface.
+// This function true after tuh_msc_mounted_cb() and false after tuh_msc_unmounted_cb()
+bool tuh_msc_mounted(uint8_t dev_addr);
+
+// Check if the interface is currently ready or busy transferring data
+bool tuh_msc_ready(uint8_t dev_addr);
+
+// Get Max Lun
+uint8_t tuh_msc_get_maxlun(uint8_t dev_addr);
+
+// Get number of block
+uint32_t tuh_msc_get_block_count(uint8_t dev_addr, uint8_t lun);
+
+// Get block size in bytes
+uint32_t tuh_msc_get_block_size(uint8_t dev_addr, uint8_t lun);
+
+// Perform a full SCSI command (cbw, data, csw) in non-blocking manner.
+// Complete callback is invoked when SCSI op is complete.
+// return true if success, false if there is already pending operation.
+bool tuh_msc_scsi_command(uint8_t dev_addr, msc_cbw_t const* cbw, void* data, tuh_msc_complete_cb_t complete_cb);
+
+// Perform SCSI Inquiry command
+// Complete callback is invoked when SCSI op is complete.
+bool tuh_msc_inquiry(uint8_t dev_addr, uint8_t lun, scsi_inquiry_resp_t* response, tuh_msc_complete_cb_t complete_cb);
+
+// Perform SCSI Test Unit Ready command
+// Complete callback is invoked when SCSI op is complete.
+bool tuh_msc_test_unit_ready(uint8_t dev_addr, uint8_t lun, tuh_msc_complete_cb_t complete_cb);
+
+// Perform SCSI Request Sense 10 command
+// Complete callback is invoked when SCSI op is complete.
+bool tuh_msc_request_sense(uint8_t dev_addr, uint8_t lun, void *resposne, tuh_msc_complete_cb_t complete_cb);
+
+// Perform SCSI Read 10 command. Read n blocks starting from LBA to buffer
+// Complete callback is invoked when SCSI op is complete.
+bool  tuh_msc_read10(uint8_t dev_addr, uint8_t lun, void * buffer, uint32_t lba, uint16_t block_count, tuh_msc_complete_cb_t complete_cb);
+
+// Perform SCSI Write 10 command. Write n blocks starting from LBA to device
+// Complete callback is invoked when SCSI op is complete.
+bool tuh_msc_write10(uint8_t dev_addr, uint8_t lun, void const * buffer, uint32_t lba, uint16_t block_count, tuh_msc_complete_cb_t complete_cb);
+
+// Perform SCSI Read Capacity 10 command
+// Complete callback is invoked when SCSI op is complete.
+// Note: during enumeration, host stack already carried out this request. Application can retrieve capacity by
+// simply call tuh_msc_get_block_count() and tuh_msc_get_block_size()
+bool tuh_msc_read_capacity(uint8_t dev_addr, uint8_t lun, scsi_read_capacity10_resp_t* response, tuh_msc_complete_cb_t complete_cb);
+
+//------------- Application Callback -------------//
+
+// Invoked when a device with MassStorage interface is mounted
+TU_ATTR_WEAK void tuh_msc_mount_cb(uint8_t dev_addr);
+
+// Invoked when a device with MassStorage interface is unmounted
+TU_ATTR_WEAK void tuh_msc_umount_cb(uint8_t dev_addr);
+
+//--------------------------------------------------------------------+
+// Internal Class Driver API
+//--------------------------------------------------------------------+
+
+void msch_init       (void);
+bool msch_open       (uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *desc_itf, uint16_t max_len);
+bool msch_set_config (uint8_t dev_addr, uint8_t itf_num);
+void msch_close      (uint8_t dev_addr);
+bool msch_xfer_cb    (uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* _TUSB_MSC_HOST_H_ */