Read only mass storage application using External NOR Flash Drive

RE: Read only mass storage application using External NOR Flash Drive

Einar Thorsrud — Mon, 17 Sep 2018 13:33:32 GMT

Yes, that is true. The SDK does not have any example where you can dynamically change between read-only and writable. Perhaps there are other file system implementations that make it easier, but I don't know of any.

RE: Read only mass storage application using External NOR Flash Drive

Kishan Patel — Fri, 14 Sep 2018 16:20:30 GMT

Hi Einar,

Since its a global def, If I set the _FS_READONLY, I wouldn't have any access to write functions. I want to write to the filesystem locally when its not mounted, and only do read only when its mounted as USB mass storage.

RE: Read only mass storage application using External NOR Flash Drive

Einar Thorsrud — Fri, 14 Sep 2018 07:01:12 GMT

Hi,

The USB MSC Example demonstrates most of what you describe here. It can use both internal flash memory, and (more relevant in your case) external flash memory via QSPI. I do not have experience with the MX66L2G45G, but I would be surprised if you run into significant problems. The example is not read-only, but that is supported by the underlying FatFs by setting the _FS_READONLY define in ffconf.h.