How to identify multiple resets to clear wifi credentials?

[yanshay]

I'm developing on ESP32S3.
I want to identify repeating resets to erase wifi credentials stored in flash.
I tried using rtc memory for that using:

#[ram(rtc_slow, persistent)]
static mut QUICK_BOOT_COUNTER: i32 = 0;
#[ram(rtc_slow, persistent)]
static mut PREV_BOOT_TIME: u64 = 0;

It works when I reset via espflash (pressing Crtl-R several times).
When I reset using the onboard reset button it doesn't.
Also, the log disconnects so I can't debug it.

Should I do this differently? It looks like the memory doesn't persist across these resets.
Is there memory that isn't erased on external button reset that I could use (other than flash)?

[bjoernQ]

RTC memory is only retained for a few reset reasons - a hard-reset (i.e. reset button) definitely won't retain RTC memory.

For saving WiFi credentials you really want to use flash memory (e.g. the NVS partition which espflash includes by default or use a custom partition). It's also what ESP-IDF does

[yanshay]

I am using the flash memory for the wifi credentials.

I'm just trying to identify multiple frequent resets using the built in reset button on the board to allow the user to reset them and other initial configurations he needs to remember . I didn't want to use the flash memory for that because it is temporary data, but seems I'll have to.

[bjoernQ]

Ah - I somehow missed that - you could at least reduce the erase cycles by not storing a counter value but toggling single bits and make use of https://docs.rs/embedded-storage/0.3.1/embedded_storage/nor_flash/trait.MultiwriteNorFlash.html