Does bootloader use Customer UICR registers?

[Collin]

I want to use the UICR customer registers to store MAC/serialization information for my devices. It looks like the UICR customer section would be great, and the product spec says they are reserved for user application, but @jldewitt mentioned here that the UICR might be used by the bootloader. Is there any documentation on this? I am using a semi-stock Nordic DFU bootloader, but haven't found any info on possible Customer UICR usage...

[Hung Bui]

Hi Collin,

If you have a look at chapter 14 in the nRF52 product spec, you can find that the first 128 bytes of the UICR are reserved for Nordic's use. You can use the rest of the space of those CUSTOMER[] register.

[John]

Hi Collin & Hung,

The comment I made in the linked question above was based on some declarations in dfu_init.h in SDK 10.0.0. I haven't checked to see if this is still in SDK12.1.0 which is what I am currently using.

Code snippet:

    /** The device info offset can be modified to place the device info settings at a different location.
  * If the customer reserved UICR location is used for other application specific data, the offset
  * must be updated to avoid collision with that data.
  */
/** [DFU UICR DEV offset] */
#define UICR_CUSTOMER_DEVICE_INFO_OFFSET    0x0                                             /**< Device info offset inside the customer UICR reserved area. Customers may change this value to place the device information in a user-preferred location. */
/** [DFU UICR DEV offset] */

#define UICR_CUSTOMER_RESERVED_OFFSET       0x80                                            /**< Customer reserved area in the UICR. The area from UICR + 0x80 is reserved for customer usage. */
#define DFU_DEVICE_INFO_BASE                (NRF_UICR_BASE + \
                                             UICR_CUSTOMER_RESERVED_OFFSET + \
                                             UICR_CUSTOMER_DEVICE_INFO_OFFSET)              /**< The device information base address inside of UICR. */
#define DFU_DEVICE_INFO                     ((dfu_device_info_t *)DFU_DEVICE_INFO_BASE)     /**< The memory mapped structure for device information data. */

#define DFU_DEVICE_TYPE_EMPTY               ((uint16_t)0xFFFF)                              /**< Mask indicating no device type is present in UICR. 0xFFFF is default flash pattern when not written with data. */
#define DFU_DEVICE_REVISION_EMPTY           ((uint16_t)0xFFFF)                              /**< Mask indicating no device revision is present in UICR. 0xFFFF is default flash pattern when not written with data. */
#define DFU_SOFTDEVICE_ANY                  ((uint16_t)0xFFFE)                              /**< Mask indicating that any SoftDevice is allowed for updating this application. Allows for easy development. Not to be used in production images. */

Regards, John

[Collin]

Thanks for the info! I just switched from 12.1.0 to 13.0.0, and I couldn't find the file dfu_init.h in either folder. I also searched for the text UICR_CUSTOMER_DEVICE_INFO_OFFSET, UICR_CUSTOMER_RESERVED_OFFSET, and DFU_DEVICE_INFO_BASE in all SDK files, and didn't get a match. That seems to imply that the customer UICR are no longer used by Nordic code, which would line up with @hungbui's response.

[Collin]

Thanks. Which SDKs is that valid for? See @jldewitt's reply above. I am most interested in SDK12 and 13.