1 /* 2 * Copyright (c) 2021 Raspberry Pi (Trading) Ltd. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #ifndef _PICO_UNIQUE_ID_H 8 #define _PICO_UNIQUE_ID_H 9 10 #include "pico.h" 11 12 #ifdef __cplusplus 13 extern "C" { 14 #endif 15 16 /** \file pico/unique_id.h 17 * \defgroup pico_unique_id pico_unique_id 18 * 19 * Unique device ID access API 20 * 21 * RP2040 does not have an on-board unique identifier (all instances of RP2040 22 * silicon are identical and have no persistent state). However, RP2040 boots 23 * from serial NOR flash devices which have a 64-bit unique ID as a standard 24 * feature, and there is a 1:1 association between RP2040 and flash, so this 25 * is suitable for use as a unique identifier for an RP2040-based board. 26 * 27 * This library injects a call to the flash_get_unique_id function from the 28 * hardware_flash library, to run before main, and stores the result in a 29 * static location which can safely be accessed at any time via 30 * pico_get_unique_id(). 31 * 32 * This avoids some pitfalls of the hardware_flash API, which requires any 33 * flash-resident interrupt routines to be disabled when called into. 34 */ 35 36 #define PICO_UNIQUE_BOARD_ID_SIZE_BYTES 8 37 38 /** 39 * \brief Unique board identifier 40 * \ingroup pico_unique_id 41 * 42 * This struct is suitable for holding the unique identifier of a NOR flash 43 * device on an RP2040-based board. It contains an array of 44 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES identifier bytes. 45 */ 46 typedef struct { 47 uint8_t id[PICO_UNIQUE_BOARD_ID_SIZE_BYTES]; 48 } pico_unique_board_id_t; 49 50 /*! \brief Get unique ID 51 * \ingroup pico_unique_id 52 * 53 * Get the unique 64-bit device identifier which was retrieved from the 54 * external NOR flash device at boot. 55 * 56 * On PICO_NO_FLASH builds the unique identifier is set to all 0xEE. 57 * 58 * \param id_out a pointer to a pico_unique_board_id_t struct, to which the identifier will be written 59 */ 60 void pico_get_unique_board_id(pico_unique_board_id_t *id_out); 61 62 /*! \brief Get unique ID in string format 63 * \ingroup pico_unique_id 64 * 65 * Get the unique 64-bit device identifier which was retrieved from the 66 * external NOR flash device at boot, formatted as an ASCII hex string. 67 * Will always 0-terminate. 68 * 69 * On PICO_NO_FLASH builds the unique identifier is set to all 0xEE. 70 * 71 * \param id_out a pointer to a char buffer of size len, to which the identifier will be written 72 * \param len the size of id_out. For full serial, len >= 2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1 73 */ 74 void pico_get_unique_board_id_string(char *id_out, uint len); 75 76 77 #ifdef __cplusplus 78 } 79 #endif 80 81 #endif 82
