1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 
15 #define PW_LOG_MODULE_NAME "KVS"
16 #define PW_LOG_LEVEL PW_KVS_LOG_LEVEL
17 
18 #include "pw_kvs/fake_flash_memory.h"
19 
20 #include "pw_kvs_private/config.h"
21 #include "pw_log/log.h"
22 
23 namespace pw::kvs {
24 
Check(std::span<FlashError> errors,FlashMemory::Address address,size_t size)25 Status FlashError::Check(std::span<FlashError> errors,
26                          FlashMemory::Address address,
27                          size_t size) {
28   for (auto& error : errors) {
29     if (Status status = error.Check(address, size); !status.ok()) {
30       return status;
31     }
32   }
33 
34   return OkStatus();
35 }
36 
Check(FlashMemory::Address start_address,size_t size)37 Status FlashError::Check(FlashMemory::Address start_address, size_t size) {
38   // Check if the event overlaps with this address range.
39   if (begin_ != kAnyAddress &&
40       (start_address >= end_ || (start_address + size) <= begin_)) {
41     return OkStatus();
42   }
43 
44   if (delay_ > 0u) {
45     delay_ -= 1;
46     return OkStatus();
47   }
48 
49   if (remaining_ == 0u) {
50     return OkStatus();
51   }
52 
53   if (remaining_ != kAlways) {
54     remaining_ -= 1;
55   }
56 
57   return status_;
58 }
59 
Erase(Address address,size_t num_sectors)60 Status FakeFlashMemory::Erase(Address address, size_t num_sectors) {
61   if (address % sector_size_bytes() != 0) {
62     PW_LOG_ERROR(
63         "Attempted to erase sector at non-sector aligned boundary; address %x",
64         unsigned(address));
65     return Status::InvalidArgument();
66   }
67   const size_t sector_id = address / sector_size_bytes();
68   if (address / sector_size_bytes() + num_sectors > sector_count()) {
69     PW_LOG_ERROR(
70         "Tried to erase a sector at an address past flash end; "
71         "address: %x, sector implied: %u",
72         unsigned(address),
73         unsigned(sector_id));
74     return Status::OutOfRange();
75   }
76 
77   std::memset(
78       &buffer_[address], int(kErasedValue), sector_size_bytes() * num_sectors);
79   return OkStatus();
80 }
81 
Read(Address address,std::span<std::byte> output)82 StatusWithSize FakeFlashMemory::Read(Address address,
83                                      std::span<std::byte> output) {
84   if (address + output.size() >= sector_count() * size_bytes()) {
85     return StatusWithSize::OutOfRange();
86   }
87 
88   // Check for injected read errors
89   Status status = FlashError::Check(read_errors_, address, output.size());
90   std::memcpy(output.data(), &buffer_[address], output.size());
91   return StatusWithSize(status, output.size());
92 }
93 
Write(Address address,std::span<const std::byte> data)94 StatusWithSize FakeFlashMemory::Write(Address address,
95                                       std::span<const std::byte> data) {
96   if (address % alignment_bytes() != 0 ||
97       data.size() % alignment_bytes() != 0) {
98     PW_LOG_ERROR("Unaligned write; address %x, size %u B, alignment %u",
99                  unsigned(address),
100                  unsigned(data.size()),
101                  unsigned(alignment_bytes()));
102     return StatusWithSize::InvalidArgument();
103   }
104 
105   if (data.size() > sector_size_bytes() - (address % sector_size_bytes())) {
106     PW_LOG_ERROR("Write crosses sector boundary; address %x, size %u B",
107                  unsigned(address),
108                  unsigned(data.size()));
109     return StatusWithSize::InvalidArgument();
110   }
111 
112   if (address + data.size() > sector_count() * sector_size_bytes()) {
113     PW_LOG_ERROR(
114         "Write beyond end of memory; address %x, size %u B, max address %x",
115         unsigned(address),
116         unsigned(data.size()),
117         unsigned(sector_count() * sector_size_bytes()));
118     return StatusWithSize::OutOfRange();
119   }
120 
121   // Check in erased state
122   for (unsigned i = 0; i < data.size(); i++) {
123     if (buffer_[address + i] != kErasedValue) {
124       PW_LOG_ERROR("Writing to previously written address: %x",
125                    unsigned(address));
126       return StatusWithSize::Unknown();
127     }
128   }
129 
130   // Check for any injected write errors
131   Status status = FlashError::Check(write_errors_, address, data.size());
132   std::memcpy(&buffer_[address], data.data(), data.size());
133   return StatusWithSize(status, data.size());
134 }
135 
FlashAddressToMcuAddress(Address address) const136 std::byte* FakeFlashMemory::FlashAddressToMcuAddress(Address address) const {
137   if (address > sector_count() * sector_size_bytes()) {
138     PW_LOG_ERROR(
139         "FlashAddressToMcuAddress beyond end of memory; address %x, max "
140         "address %x",
141         unsigned(address),
142         unsigned(sector_count() * sector_size_bytes()));
143     return nullptr;
144   }
145   return buffer_.data() + address;
146 }
147 
148 }  // namespace pw::kvs
149