A filesystem and raw block access to the same QSPI flash

RE: A filesystem and raw block access to the same QSPI flash

mrono — Mon, 30 Aug 2021 10:12:49 GMT

Ok, I can now alternate between file access and raw block access. I combined the write-read test routine from the qspi example and the fatfs file access tests from usbd_msc.

Now I need to add these to my actual application. And implement a file transfer method over BLE.

RE: A filesystem and raw block access to the same QSPI flash

mrono — Mon, 30 Aug 2021 07:46:35 GMT

Sorry for the delay, I needed to work on something else last week.

I got this part working. I checked how the block_dev_ram implementation specified an address range, and followed that. So instead of altering the shared geometry struct, I added the offset and size to the block_dev_qspi's config-structure.

This seems to be working. I still need to integrate the raw block access routines and verify that I can alternate between the two.

RE: A filesystem and raw block access to the same QSPI flash

ovrebekk — Fri, 20 Aug 2021 14:03:04 GMT

Unfortunately the guy that developed the nrf_block_dev modules is on vacation at the moment, but looking at the code I can't see any reference to any offset variables or similar that would allow you to start at an address > 0 in the external flash.

As far as I can tell the nrf_block_dev_qspi.c implementation would have to be changed, in order to add a constant offset to the block index for every call to one of the nrf_drv_qspi_read/write/erase functions.

The blk_count variable in the nrf_block_dev_geometry_t struct would then need to be reduced by the same amount, to make sure you don't try to access memory beyond the boundaries of the flash module.

Best regards
Torbjørn