mimxrt: Add optional MSC support.

Add MSC support using internal flash storage or SD card.

Note this is disabled by default, and can be enabled by boards if needed.

Signed-off-by: iabdalkader <i.abdalkader@gmail.com>

ports/mimxrt/Makefile

@@ -217,6 +217,7 @@ SRC_C += \
 	modmimxrt.c \
 	mphalport.c \
 	mpnetworkport.c \
+	msc_disk.c \
 	network_lan.c \
 	pendsv.c \
 	pin.c \

ports/mimxrt/main.c

@@ -39,6 +39,7 @@
 #include "led.h"
 #include "pendsv.h"
 #include "modmachine.h"
+#include "modmimxrt.h"
 
 #if MICROPY_PY_LWIP
 #include "lwip/init.h"
@@ -55,6 +56,7 @@
 
 #include "systick.h"
 #include "extmod/modnetwork.h"
+#include "extmod/vfs.h"
 
 extern uint8_t _sstack, _estack, _gc_heap_start, _gc_heap_end;
 
@@ -113,6 +115,19 @@ int main(void) {
         // Execute _boot.py to set up the filesystem.
         pyexec_frozen_module("_boot.py", false);
 
+        #if MICROPY_HW_USB_MSC
+        // Set the USB medium to flash block device.
+        mimxrt_msc_medium = &mimxrt_flash_type;
+
+        #if MICROPY_PY_MACHINE_SDCARD
+        const char *path = "/sdcard";
+        // If SD is mounted, set the USB medium to SD.
+        if (mp_vfs_lookup_path(path, &path) != MP_VFS_NONE) {
+            mimxrt_msc_medium = &machine_sdcard_type;
+        }
+        #endif
+        #endif
+
         // Execute user scripts.
         int ret = pyexec_file_if_exists("boot.py");
 

ports/mimxrt/modmimxrt.c

@@ -31,6 +31,9 @@
 static const mp_rom_map_elem_t mimxrt_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__),            MP_ROM_QSTR(MP_QSTR_mimxrt) },
     { MP_ROM_QSTR(MP_QSTR_Flash),               MP_ROM_PTR(&mimxrt_flash_type) },
+    #if MICROPY_HW_USB_MSC
+    { MP_ROM_QSTR(MP_QSTR_MSC),                 MP_ROM_TRUE },
+    #endif
 };
 static MP_DEFINE_CONST_DICT(mimxrt_module_globals, mimxrt_module_globals_table);
 

ports/mimxrt/modmimxrt.h

@@ -30,5 +30,6 @@
 
 extern const mp_obj_type_t mimxrt_flash_type;
 extern const mp_obj_module_t mp_module_mimxrt;
+extern const mp_obj_type_t *mimxrt_msc_medium;
 
 #endif // MICROPY_INCLUDED_MIMXRT_MODMIMXRT_H

ports/mimxrt/mpconfigport.h

@@ -151,8 +151,15 @@ uint32_t trng_random_u32(void);
 #endif
 
 #define MICROPY_HW_ENABLE_USBDEV            (1)
+// Enable USB-CDC serial port
+#ifndef MICROPY_HW_USB_CDC
 #define MICROPY_HW_USB_CDC                  (1)
 #define MICROPY_HW_USB_CDC_1200BPS_TOUCH    (1)
+#endif
+// Enable USB Mass Storage with FatFS filesystem.
+#ifndef MICROPY_HW_USB_MSC
+#define MICROPY_HW_USB_MSC                  (0)
+#endif
 
 // Hooks to add builtins
 

ports/mimxrt/msc_disk.c

@@ -0,0 +1,153 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020-2021 Damien P. George
+ * Copyright (c) 2024-2025 Ibrahim Abdelkader <iabdalkader@openmv.io>
+ *
+ * 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.
+ *
+ */
+#include "tusb.h"
+#if CFG_TUD_MSC
+#include "flash.h"
+#include BOARD_FLASH_OPS_HEADER_H
+#include "stdlib.h"
+#include "modmimxrt.h"
+#if MICROPY_PY_MACHINE_SDCARD
+#include "sdcard.h"
+
+#ifndef MICROPY_HW_SDCARD_SDMMC
+#define MICROPY_HW_SDCARD_SDMMC (1)
+#endif
+
+#define MSC_SDCARD_INDEX    (MICROPY_HW_SDCARD_SDMMC - 1)
+#endif
+
+// This implementation does Not support Flash sector caching.
+// MICROPY_FATFS_MAX_SS  must be identical to SECTOR_SIZE_BYTES
+#define BLOCK_SIZE          (SECTOR_SIZE_BYTES)
+#define BLOCK_COUNT         (MICROPY_HW_FLASH_STORAGE_BYTES / BLOCK_SIZE)
+#define FLASH_BASE_ADDR     (MICROPY_HW_FLASH_STORAGE_BASE)
+
+static bool msc_ejected = false;
+
+const mp_obj_type_t *mimxrt_msc_medium = NULL;
+
+// 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]) {
+    memcpy(vendor_id, MICROPY_HW_USB_MSC_INQUIRY_VENDOR_STRING, MIN(strlen(MICROPY_HW_USB_MSC_INQUIRY_VENDOR_STRING), 8));
+    memcpy(product_id, MICROPY_HW_USB_MSC_INQUIRY_PRODUCT_STRING, MIN(strlen(MICROPY_HW_USB_MSC_INQUIRY_PRODUCT_STRING), 16));
+    memcpy(product_rev, MICROPY_HW_USB_MSC_INQUIRY_REVISION_STRING, MIN(strlen(MICROPY_HW_USB_MSC_INQUIRY_REVISION_STRING), 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) {
+    if (msc_ejected || mimxrt_msc_medium == NULL) {
+        tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x3a, 0x00);
+        return false;
+    }
+    return true;
+}
+
+// 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) {
+    if (mimxrt_msc_medium == &mimxrt_flash_type) {
+        *block_size = BLOCK_SIZE;
+        *block_count = BLOCK_COUNT;
+    #if MICROPY_PY_MACHINE_SDCARD
+    } else if (mimxrt_msc_medium == &machine_sdcard_type) {
+        mimxrt_sdcard_obj_t *card = &mimxrt_sdcard_objs[MSC_SDCARD_INDEX];
+        *block_size = card->block_len;
+        *block_count = card->block_count;
+    #endif
+    }
+}
+
+// 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
+bool tud_msc_start_stop_cb(uint8_t lun, uint8_t power_condition, bool start, bool load_eject) {
+    if (load_eject) {
+        if (start) {
+            // load disk storage
+            msc_ejected = false;
+        } else {
+            // unload disk storage
+            msc_ejected = true;
+        }
+    }
+    return true;
+}
+
+// Callback invoked when received READ10 command.
+// Copy disk's data to buffer (up to bufsize) and return number of copied bytes.
+int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void *buffer, uint32_t bufsize) {
+    if (mimxrt_msc_medium == &mimxrt_flash_type) {
+        flash_read_block(FLASH_BASE_ADDR + lba * BLOCK_SIZE, buffer, bufsize);
+    #if MICROPY_PY_MACHINE_SDCARD
+    } else if (mimxrt_msc_medium == &machine_sdcard_type) {
+        mimxrt_sdcard_obj_t *card = &mimxrt_sdcard_objs[MSC_SDCARD_INDEX];
+        sdcard_read(card, buffer, lba, bufsize / card->block_len);
+    #endif
+    }
+    return bufsize;
+}
+
+// Callback invoked when received WRITE10 command.
+// Process data in buffer to disk's storage and return number of written bytes
+int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t *buffer, uint32_t bufsize) {
+    if (mimxrt_msc_medium == &mimxrt_flash_type) {
+        // Erase count sectors starting at lba
+        for (int n = 0; n < (bufsize / BLOCK_SIZE); n++) {
+            flash_erase_sector(FLASH_BASE_ADDR + (lba + n) * BLOCK_SIZE);
+        }
+        flash_write_block(FLASH_BASE_ADDR + lba * BLOCK_SIZE, buffer, bufsize);
+    #if MICROPY_PY_MACHINE_SDCARD
+    } else if (mimxrt_msc_medium == &machine_sdcard_type) {
+        mimxrt_sdcard_obj_t *card = &mimxrt_sdcard_objs[MSC_SDCARD_INDEX];
+        sdcard_write(card, buffer, lba, bufsize / card->block_len);
+
+    #endif
+    }
+    return bufsize;
+}
+
+// Callback invoked when received an SCSI command not in built-in list below
+// - READ_CAPACITY10, READ_FORMAT_CAPACITY, INQUIRY, MODE_SENSE6, REQUEST_SENSE
+// - READ10 and WRITE10 has their own callbacks
+int32_t tud_msc_scsi_cb(uint8_t lun, uint8_t const scsi_cmd[16], void *buffer, uint16_t bufsize) {
+    int32_t resplen = 0;
+    switch (scsi_cmd[0]) {
+        case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
+            // Sync the logical unit if needed.
+            break;
+
+        default:
+            // Set Sense = Invalid Command Operation
+            tud_msc_set_sense(lun, SCSI_SENSE_ILLEGAL_REQUEST, 0x20, 0x00);
+            // negative means error -> tinyusb could stall and/or response with failed status
+            resplen = -1;
+            break;
+    }
+    return resplen;
+}
+#endif