UUID not populating correctly from Winbond Flash

[Poofjunior]

We might have the wrong library function call. The right call may be:

    uint8_t arr[8];
    flash_get_unique_id(arr);
    // pico_unique_board_id_t unique_id;
    // pico_get_unique_board_id(&unique_id);
    memcpy((void*)(&regs.R_UUID[8]), (void*)&arr, sizeof(arr));
 

[Poofjunior]

It looks like there is a sub-issue here related to the pico-sdk:
raspberrypi/pico-sdk#2291

It appears that the unique id, as printed to the usb device descriptors, is printed as big-endian. If we read the data and output the data as little-endian (which is consistent with how the board reads the device from the Winbond flash), we would get a little-endian result that disagrees with the iSerial usb descriptor field.

[Poofjunior]

It appears that this works in some devices (harp.device.white-rabbit) but not others (harp.device.environment-sensor), even when both are using the same version of the pico sdk and Harp core. Here's a screenshot of the register dump across a working device (top) and not-working device (bottom)