how to enable readback protection

[nimalhuang]

Hi, Guys,

I am trying to enable the readback protection for the code region 0 and code region 1, I know that the NRF_UICR->RBPCONF register is flash_backed, so I have to include uicr_config.h file and uncomment the line
const uint32_t UICR_RBPCONF attribute((at(0x10001004))) attribute((used)) = 0xFFFF0000;

However, I use eclipse and gcc, so it seems the "at" keyword doesn't apply in eclipse gcc, so is there any equivalence in gcc or how should I enable this readback protection in the application but not using nrfgo, I know that the nrfgo can definitely do that. Thank you:)

[RK]

A search in the forums shows this answer

devzone.nordicsemi.com/.../

which says it's not trivial and probably involves reading the ld manual. I assume you want to embed the data in your application so that when it's flashed the UICR is written. If I were going to do that I'd probably write a small .bin/.hex file with the values I want flashed in and add a step to merge it in with my code .hex file at the end using objcopy.

[endnode]

Hi,

You can either write UICR->RBPCONF from within the application by something like this:

#if LOCK_UICR
    // Check if read-back mechanism is turned ON.
    if((uint32_t)((NRF_UICR->RBPCONF & UICR_RBPCONF_PALL_Msk) >> UICR_RBPCONF_PALL_Pos) != UICR_RBPCONF_PALL_Enabled) {
        ble_flash_word_write((uint32_t *)&NRF_UICR->RBPCONF, (NRF_UICR->RBPCONF & ~UICR_RBPCONF_PALL_Msk));
    }
#endif

or you can put something like this to the end of your HEX file:

:020000041000EA
:10100000FFFFFFFFFF00FFFFFFFFFFFFFFFFFFFFEF
:00000001FF

[Hung Bui]

I think you can follow what we did here to write the bootloader address to UICR:

__attribute__ ((section(".uicrBootStartAddress"))) uint32_t m_uicr_bootloader_start_address = BOOTLOADER_REGION_START;

Note: You would need to define the uicrBootStartAddress section in the .ld file as in gcc_nrf51_bootloader_xxaa.ld file.

Example project: bootloader - gcc - BLE - TestRBP.zip

[nimalhuang]

Hi, Thank you for your reply. Because I enable softdevice s130, using function ble_flash while softdevice running will halt the cpu and hence cause hard fault, so this is not gonna work.

[nimalhuang]

Hi, Huang

I add code as you said, but it doesn't work. I add the following code in the main.c:

attribute((section(".uicrrbpconf"))) uint32_t UICR_ADDR_0x04 = 0xffff0000;

and define the ".uicrrbpconf" section in ld file:

.uicrrbpconf 0x10001004 : {

}

Is there anything that I have missed? Thank you