nRF52832 internal flash memory with littlefs

RE: nRF52832 internal flash memory with littlefs

Einar Thorsrud — Wed, 29 Jun 2022 10:54:10 GMT

Hi,

I have tested and looked at your sample. I must admit I am far from a littlefs expert, but the approach in general seems sensible, and is the about the same as is used in the littlefs File System Sample Application. However, updating or overwriting flash data involves deleting and writing to a new location (as bits can only be flipped from 0 to 1 by a page erase), and this will not be possible when the flash is full. So you will need to update the data before the flash is full (and perhaps also consider using multiple files).

RE: nRF52832 internal flash memory with littlefs

Davorin Madaric — Tue, 28 Jun 2022 08:35:37 GMT

Here is sample:
https://github.com/davorinm/littlefsSample

Board used nrf52dk_nrf52832.
Dtk is not modified, storage partition is 24kB.

After about a minute write will begin to fail.

Thank you!

RE: nRF52832 internal flash memory with littlefs

Davorin Madaric — Tue, 28 Jun 2022 06:42:15 GMT

CONFIG_FS_LOG_LEVEL_DBG=y did not reveal anything new.

This is my log:

This is first unsuccessful write at data file index 12240. It fails on fs_write():

[00:03:39.664,245] <dbg> main.dataDetected: newDataDetected
[00:03:39.669,860] <dbg> dataStorage.writeData: seek data to: 12240, 0
[00:03:39.940,765] <err> littlefs: WEST_TOPDIR/modules/fs/littlefs/lfs.c:567: No more free space 10
[00:03:39.940,795] <err> fs: file write error (-28)
[00:03:39.940,795] <dbg> dataStorage.writeData: write new data to: 12240, -28
[00:03:39.940,826] <err> dataStorage: data write error, no more space left: -28

Set data file index to 0, retry to write, fs_write succeded but fails on fs_close
From this point on fs_write suceeds to write, data file index is incremented, fs_close fails with error -28 (-ENOSPC)

[00:03:39.946,380] <dbg> dataStorage.writeData: seek data to: 0, 0
[00:03:40.092,834] <dbg> dataStorage.writeData: write new data to: 0, 40
[00:03:40.292,480] <err> littlefs: WEST_TOPDIR/modules/fs/littlefs/lfs.c:567: No more free space 10
[00:03:40.292,510] <err> fs: file close error (-28)
[00:03:40.292,541] <err> dataStorage: File close error: -28
[00:03:40.292,541] <dbg> dataStorage.dataStorage_addData: data write #2 sucess: 40
[00:03:40.298,065] <dbg> dataStorage.writeDataFileIndex: write new data_file_index: 40, ret: 4

[00:03:40.809,844] <dbg> main.dataDetected: newDataDetected
[00:03:40.815,765] <dbg> dataStorage.writeData: seek data to: 40, 0
[00:03:40.994,689] <dbg> dataStorage.writeData: write new data to: 40, 40
[00:03:41.192,596] <err> littlefs: WEST_TOPDIR/modules/fs/littlefs/lfs.c:567: No more free space 10
[00:03:41.192,626] <err> fs: file close error (-28)
[00:03:41.192,626] <err> dataStorage: File close error: -28
[00:03:41.198,211] <dbg> dataStorage.writeDataFileIndex: write new data_file_index: 80, ret: 4

[00:03:41.699,188] <dbg> main.dataDetected: newDataDetected
[00:03:41.704,833] <dbg> dataStorage.writeData: seek data to: 80, 0
[00:03:41.834,899] <dbg> dataStorage.writeData: write new data to: 80, 40
[00:03:42.032,684] <err> littlefs: WEST_TOPDIR/modules/fs/littlefs/lfs.c:567: No more free space 10
[00:03:42.032,714] <err> fs: file close error (-28)
[00:03:42.032,714] <err> dataStorage: File close error: -28
[00:03:42.038,299] <dbg> dataStorage.writeDataFileIndex: write new data_file_index: 120, ret: 4

In this case file system is 24kB in size, but this write fails on 12kB.

I will prepare an example.

RE: nRF52832 internal flash memory with littlefs

Einar Thorsrud — Mon, 27 Jun 2022 17:06:32 GMT

Hi,

-ENOSPC indicate that there is no more space, and this corresponds to LFS_ERR_NOSPC. I do not notice anything sticking out as incorrect in what you describe. Can you enable logging and also add CONFIG_FS_LOG_LEVEL_DBG=y and see if the log revels anything?

If you don't make progress it would be interesting to test on my end if you have a minimal failing example that runs on a DK so that I can test on my end.