RE: nRF52832 SPI flash init/boot failure

Hung Bui — Tue, 23 Jun 2026 13:07:05 GMT

Hi Oliver,

I agree that it could be timing issue. How often do you experience the issue ? My understanding is that you saw the issue when you do DFU update and after the image transfer completely and the device reset it won't be able to update the new image ?

Could you try to do a flash dump of the internal flash when the issue happen ? There could be some metadata MCUBoot store on the internal flash that may make the change in timing/activity and cause the problem. We can compare to the flash when the device is working.

Could you show the schematic and name of the external flash ?

RE: nRF52832 SPI flash init/boot failure

Revilo — Tue, 23 Jun 2026 09:12:12 GMT

While posting this, your AI suggested to reset SPIM in an early boot stage (so did another AI after I copied the initial post in it's input). So I removed assertions and logging from Kconfig an added the following to my main.c. The DFU still fails. I tried some sequence variations.

#include <nrfx_spim.h>
#include <zephyr/init.h>

#define EXT_FLASH_SPI_IDX 2 // index has to be in sync with dts

static int init_rstExtFlashSpi()
{
    // reset driver
    const nrfx_spim_t extFlashSpi = NRFX_SPIM_INSTANCE(EXT_FLASH_SPI_IDX);
    nrfx_spim_uninit(&extFlashSpi);

    // force reset peripheral hardware
    __DSB();
    __ISB();
    PP_CAT(NRF_SPIM, EXT_FLASH_SPI_IDX)->ENABLE = 0;
    __DSB();
    __ISB();
    PP_CAT(NRF_SPIM, EXT_FLASH_SPI_IDX)->PSEL.SCK = 0xFFFFFFFF;
    PP_CAT(NRF_SPIM, EXT_FLASH_SPI_IDX)->PSEL.MOSI = 0xFFFFFFFF;
    PP_CAT(NRF_SPIM, EXT_FLASH_SPI_IDX)->PSEL.MISO = 0xFFFFFFFF;
    __DSB();
    __ISB();

    return 0;
}

#undef EXT_FLASH_SPI_IDX

SYS_INIT(init_rstExtFlashSpi, EARLY, 0);

What would you suggest trying next?