nRF52840 - Zephyr OS - Flash Protection

RE: nRF52840 - Zephyr OS - Flash Protection

SirBranch — Tue, 17 Aug 2021 13:50:26 GMT

Thanks for all the help and the following up! 😃

RE: nRF52840 - Zephyr OS - Flash Protection

Sigurd — Tue, 17 Aug 2021 09:52:23 GMT

[quote user="SirBranch"]looking forward for when this gets added as a Kconfig![/quote]

A PR have been created for this now.

https://github.com/zephyrproject-rtos/zephyr/pull/37732

RE: nRF52840 - Zephyr OS - Flash Protection

SirBranch — Wed, 11 Aug 2021 14:19:30 GMT

Thanks for the insight, much appreciated!

I'll look into getting that to run on Zephyr using the HAL, looking forward for when this gets added as a Kconfig!

Thanks for the help

RE: nRF52840 - Zephyr OS - Flash Protection

Sigurd — Tue, 10 Aug 2021 15:10:44 GMT

[quote user=""]Any insight into how to achieve this on Zephyr RTOS would be greatly appreciated.[/quote]

There are no Kconfig or similar in Zephyr for this, but we are looking into adding this.

Here are some code on how to enable it:

void nrf_bootloader_debug_port_disable(void)
{
    if (NRF_UICR->APPROTECT != 0x0)
    {
        nrf_nvmc_write_word((uint32_t)&NRF_UICR->APPROTECT, 0x0);
        NVIC_SystemReset();
    }
#if (!defined (NRF52810_XXAA) && !defined (NRF52811_XXAA) && !defined (NRF52832_XXAA) && !defined (NRF52832_XXAB))
    if (NRF_UICR->DEBUGCTRL != 0x0)
    {
        nrf_nvmc_write_word((uint32_t)&NRF_UICR->DEBUGCTRL, 0x0);
        NVIC_SystemReset();
    }
#endif
}

RE: nRF52840 - Zephyr OS - Flash Protection

SirBranch — Mon, 09 Aug 2021 14:19:11 GMT

To provide an update on the state of this ticket:

I'm currently able to protect with the known nrfjprog command:

nrfjprog --rbp ALL -f NRF52

But I'm looking for a way to do this from the application code. I've set CONFIG_SOC_FLASH_NRF_UICR=y from the bootloader configuration as well as application and I'm currently able to read in run time using:

NRF_UICR->APPROTECT

But this reference doesn't seem to allow for writing or clearing. I've tried using the flash API in the following manner to read/write but no success in even being able to read:

#define PER_UICR 0x10001000UL
#define UICR_REG_APPROTECT 0x208UL

void uicr_reg_approtect_read(void){

	const struct device* flash_dev = device_get_binding(DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL);
    uint32_t reg_approtect = 0UL;

    if (flash_dev == NULL) {
        LOG_ERR("Nordic nRF52 flash driver was not found!\n");
        return;
    }  // Check status

    LOG_WRN("Found flash controller %s", log_strdup(DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL));

    err = flash_read(flash_dev, PER_UICR + UICR_REG_APPROTECT, &reg_approtect, sizeof(uint32_t));

    if (err != 0) {
        LOG_WRN("Flash read of REG_APPROTECT failed! %d\n", err);
    } else {
        LOG_WRN("UICR - REG_APPROTECT 0x%X", reg_approtect);
    }

}