USBX MSC *media_status value meaning

[ABasi.2]

Hello!

i'm developing a firmware that use an SD card connected to USBX MSC, and i have a couple of question

i want to understand better the  ULONG *media_status value returned in the function :

UINT USBD_STORAGE_Status(VOID *storage_instance, ULONG lun,
                         ULONG media_id,ULONG *media_status) 

UINT USBD_STORAGE_Flush(VOID *storage_instance, ULONG lun, ULONG number_blocks,
                        ULONG lba, ULONG *media_status)

UINT USBD_STORAGE_Write(VOID *storage_instance, ULONG lun, UCHAR *data_pointer,
                        ULONG number_blocks, ULONG lba, ULONG *media_status) 

UINT USBD_STORAGE_Read(VOID *storage_instance, ULONG lun, UCHAR *data_pointer,
                       ULONG number_blocks, ULONG lba, ULONG *media_status)                

 i'm hoping that value is related to the SCSI code value that windows need from a USB MSC

is it true? beyond UX_SUCCESS which value can i use? for example to indicate the media as changed  or is readonly?

how can the functions ULONG USBD_STORAGE_GetMediaLastLba(VOID) and ULONG USBD_STORAGE_GetMediaBlocklength(VOID) can be fired againafter initialization? (maybe i have changed the SD card)

whats the meaning of this function? 

UINT USBD_STORAGE_Notification(VOID *storage_instance, ULONG lun, ULONG media_id,
                               ULONG notification_class, UCHAR **media_notification,
                               ULONG *media_notification_length)

thank you!

best reguards

[FBL]

Hi @ABasi.2 

Thanks a lot for your patience and for raising these detailed points.

Following up on ticket 223015, I checked internally with our USBX team. Unfortunately, at this stage, there is no plan to provide an MSC example implementing multi‑LUN.

I found something interesting that may help you. 

[ABasi.2]

Hello FBL

thank you for the link

BUT

my question is quite different

i don't need a multi lun example

if you read our previos conversation you can check that:

i need to make a project in which i connect my board to a computer like a MSC, then i can add,remove,modify file via USB (i can do that) and i can use that files readed from the microcontroller

also i want to modify that files from microcontroller file and read from PC

i understand that is not possible to use the memory simultanuosely, but for sure there is a method in which i "firmware disconnect" the memory from USB , use it end then reconnect to USB

also there is usually code to send to PC to make the PC to re-read the content of the memory and show on PC

if my question isn't clear please let me know

best reguards