read_uid.c

00001 /**
00002  * @file    read_uid.c
00003  * @brief
00004  *
00005  * DAPLink Interface Firmware
00006  * Copyright (c) 2009-2016, ARM Limited, All Rights Reserved
00007  * SPDX-License-Identifier: Apache-2.0
00008  *
00009  * Licensed under the Apache License, Version 2.0 (the "License"); you may
00010  * not use this file except in compliance with the License.
00011  * You may obtain a copy of the License at
00012  *
00013  * http://www.apache.org/licenses/LICENSE-2.0
00014  *
00015  * Unless required by applicable law or agreed to in writing, software
00016  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00017  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00018  * See the License for the specific language governing permissions and
00019  * limitations under the License.
00020  */
00021 
00022 #include "read_uid.h"
00023 #include "cortex_m.h"
00024 
00025 #define IAP_LOCATION  *(volatile unsigned int *)(0x10400100)
00026 static uint32_t command[5];
00027 static uint32_t result[5];
00028 typedef void (*IAP)(uint32_t[], uint32_t[]);
00029 
00030 void read_unique_id(uint32_t *id)
00031 {
00032 #if defined(INTERNAL_FLASH)
00033     cortex_int_state_t local_state = cortex_int_get_and_disable();
00034 
00035     // readUID IAP call
00036     IAP iap_entry = (IAP)IAP_LOCATION;
00037     command[0] = 58;
00038     iap_entry(command, result);
00039     *id = result[1] ^ result[2] ^ result[3] ^ result[4];
00040 
00041     cortex_int_restore(local_state);
00042 #else
00043     // IAP commands are only supported for parts with on-chip flash.
00044     (void)command;
00045     (void)result;
00046     *id = 0xdeadbeef;
00047 #endif
00048 }