1 /**
2  *
3  * Built with ARM Mbed-OS
4  *
5  * Copyright (c) 2019-2021 Embedded Planet, Inc.
6  * SPDX-License-Identifier: Apache-2.0
7  *
8  * Licensed under the Apache License, Version 2.0 (the "License");
9  * you may not use this file except in compliance with the License.
10  * You may obtain a copy of the License at
11  *
12  *     http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing, software
15  * distributed under the License is distributed on an "AS IS" BASIS,
16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  * See the License for the specific language governing permissions and
18  * limitations under the License.
19  */
20 
21 #if MCUBOOT_DATA_SHARING && !MCUBOOT_BOOTLOADER_BUILD
22 
23 #include "DataShare.h"
24 #include "boot_status.h"
25 
26 #include <cstring>
27 
28 #define PTR_TO_UINT8(x) ((volatile uint8_t *) x)
29 #define PTR_TO_UINT16(x) ((volatile uint16_t *) x)
30 #define PTR_TO_UINT32(x) ((volatile uint32_t *) x)
31 
32 #define SHARED_DATA_ENTRY_BASE MCUBOOT_SHARED_DATA_BASE+SHARED_DATA_HEADER_SIZE
33 
DataShare(uint8_t * shared_base)34 DataShare::DataShare(uint8_t *shared_base) : _shared_base(shared_base) {
35     volatile uint16_t *ptr = PTR_TO_UINT16(MCUBOOT_SHARED_DATA_BASE);
36 
37     /* Validate magic word */
38     if(*ptr++ == SHARED_DATA_TLV_INFO_MAGIC) {
39         _is_valid = true;
40     }
41 
42     _total_size = *ptr;
43 
44 }
45 
is_valid()46 bool DataShare::is_valid() {
47     return _is_valid;
48 }
49 
get_total_size()50 uint16_t DataShare::get_total_size() {
51     if(!is_valid()) {
52         return 0;
53     }
54 
55     return _total_size;
56 }
57 
get_next(uint16_t * type,mbed::Span<uint8_t> buf,uint16_t * actual_size)58 int DataShare::get_next(uint16_t *type, mbed::Span<uint8_t> buf, uint16_t *actual_size) {
59 
60     if(!is_valid()) {
61         return DATA_SHARE_ERROR_CORRUPT;
62     }
63 
64     if(_current_offset >= (_total_size - SHARED_DATA_HEADER_SIZE)) {
65         return DATA_SHARE_ERROR_EOF;
66     }
67 
68     uint16_t working_offset = _current_offset;
69 
70     /* Get the type and the length */
71     *type = *PTR_TO_UINT16((SHARED_DATA_ENTRY_BASE + working_offset));
72     working_offset += sizeof(uint16_t);
73     *actual_size = *PTR_TO_UINT16((SHARED_DATA_ENTRY_BASE + working_offset));
74     working_offset += sizeof(uint16_t);
75 
76     /* Check if the output buffer is large enough */
77     if((size_t)buf.size() < *actual_size) {
78         return DATA_SHARE_ERROR_OUT_OF_MEM;
79     }
80 
81     /* Copy data of TLV entry */
82     memcpy(buf.data(), (const uint8_t*)PTR_TO_UINT8((SHARED_DATA_ENTRY_BASE + working_offset)), *actual_size);
83 
84     working_offset += *actual_size;
85 
86     /* Update state */
87     _current_offset = working_offset;
88 
89     return DATA_SHARE_OK;
90 
91 }
92 
rewind()93 void DataShare::rewind() {
94     _current_offset = 0;
95 }
96 
97 #endif /* MCUBOOT_DATA_SHARING && !MCUBOOT_BOOTLOADER_BUILD */
98