SETTINGS subsystem(CONFIG_SETTINGS) with FCB (SETTINGS_FCB) storage back-end does not work on STM32U575

[zafersn]

tested setting subsys module (CONFIG_SETTINGS) on the stm32u575 and settings_backend_init returns an error <err> flash_stm32: Write range invalid. Offset: 983040, len: 8 . so went into this problem and stm32u5 doesnt accept if written data' offeset and len is not a multiple of FLASH_STM32_WRITE_BLOCK_SIZE (16 bytes)

and here is where the size is given.

sizeof(fda) = 8 bytes

So, am I wrong here, or is it an issue?

[Laczen]

@zafersn, this is a bug. FCB at the moment does not seem to support write-block-size > 8 as a result of how the sector header is written/read.

[zafersn]

@Laczen Thanks for your reply. Is there an issue created for this? I can follow it up to stay updated? if you know, could you please mention here?

[Laczen]

I don't think this has been reported as an issue/bug. The fix should be quite trivial: create a buffer that is correctly sized fcb_get_length(..., size_of(fda)), copy the fda to the start of this buffer, and write the buffer.