src/rp2_common/pico_unique_id/unique_id.c (PicoSDK)

/* * Copyright (c) 2021 Raspberry Pi (Trading) Ltd. * * SPDX-License-Identifier: BSD-3-Clause */ #include "hardware/flash.h" #include "pico/bootrom.h" #include "pico/unique_id.h" static_assert(PICO_UNIQUE_BOARD_ID_SIZE_BYTES == FLASH_UNIQUE_ID_SIZE_BYTES, "Board ID size must match flash ID size"); static pico_unique_board_id_t retrieved_id; static void __attribute__((constructor)) _retrieve_unique_id_on_boot(void) { #if PICO_RP2040 #if PICO_NO_FLASH // The hardware_flash call will panic() if called directly on a NO_FLASH // build. Since this constructor is pre-main it would be annoying to // debug, so just produce something well-defined and obviously wrong. for (int i = 0; i < PICO_UNIQUE_BOARD_ID_SIZE_BYTES; i++) retrieved_id.id[i] = 0xee; #else flash_get_unique_id(retrieved_id.id); #endif #else rom_get_sys_info_fn func = (rom_get_sys_info_fn) rom_func_lookup(ROM_FUNC_GET_SYS_INFO); union { uint32_t words[9]; uint8_t bytes[9 * 4]; } out; __unused int rc = func(out.words, 9, SYS_INFO_CHIP_INFO); assert(rc == 4); for (int i = 0; i < PICO_UNIQUE_BOARD_ID_SIZE_BYTES; i++) { retrieved_id.id[i] = out.bytes[PICO_UNIQUE_BOARD_ID_SIZE_BYTES - 1 + 2 * 4 - i]; } #endif } void pico_get_unique_board_id(pico_unique_board_id_t *id_out) { *id_out = retrieved_id; } void pico_get_unique_board_id_string(char *id_out, uint len) { assert(len > 0); size_t i; // Generate hex one nibble at a time for (i = 0; (i < len - 1) && (i < PICO_UNIQUE_BOARD_ID_SIZE_BYTES * 2); i++) { int nibble = (retrieved_id.id[i/2] >> (4 - 4 * (i&1))) & 0xf; id_out[i] = (char)(nibble < 10 ? nibble + '0' : nibble + 'A' - 10); } id_out[i] = 0; }