xref: /aosp_15_r20/external/pigweed/pw_kvs/fake_flash_memory.cc (revision 61c4878ac05f98d0ceed94b57d316916de578985)
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 "PW_FLASH"
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(span<FlashError> errors,FlashMemory::Address address,size_t size)25 Status FlashError::Check(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 
60 Vector<FlashError, 0> FakeFlashMemory::no_errors_;
61 
Erase(Address address,size_t num_sectors)62 Status FakeFlashMemory::Erase(Address address, size_t num_sectors) {
63   if (address % sector_size_bytes() != 0) {
64     PW_LOG_ERROR(
65         "Attempted to erase sector at non-sector aligned boundary; address %x",
66         unsigned(address));
67     return Status::InvalidArgument();
68   }
69   const size_t sector_id = address / sector_size_bytes();
70   if (address / sector_size_bytes() + num_sectors > sector_count()) {
71     PW_LOG_ERROR(
72         "Tried to erase a sector at an address past flash end; "
73         "address: %x, sector implied: %u",
74         unsigned(address),
75         unsigned(sector_id));
76     return Status::OutOfRange();
77   }
78 
79   std::memset(
80       &buffer_[address], int(kErasedValue), sector_size_bytes() * num_sectors);
81   return OkStatus();
82 }
83 
Read(Address address,span<std::byte> output)84 StatusWithSize FakeFlashMemory::Read(Address address, span<std::byte> output) {
85   if (address + output.size() >= sector_count() * size_bytes()) {
86     return StatusWithSize::OutOfRange();
87   }
88 
89   // Check for injected read errors
90   Status status = FlashError::Check(read_errors_, address, output.size());
91   std::memcpy(output.data(), &buffer_[address], output.size());
92   return StatusWithSize(status, output.size());
93 }
94 
Write(Address address,span<const std::byte> data)95 StatusWithSize FakeFlashMemory::Write(Address address,
96                                       span<const std::byte> data) {
97   if (address % alignment_bytes() != 0 ||
98       data.size() % alignment_bytes() != 0) {
99     PW_LOG_ERROR("Unaligned write; address %x, size %u B, alignment %u",
100                  unsigned(address),
101                  unsigned(data.size()),
102                  unsigned(alignment_bytes()));
103     return StatusWithSize::InvalidArgument();
104   }
105 
106   if (address + data.size() > sector_count() * sector_size_bytes()) {
107     PW_LOG_ERROR(
108         "Write beyond end of memory; address %x, size %u B, max address %x",
109         unsigned(address),
110         unsigned(data.size()),
111         unsigned(sector_count() * sector_size_bytes()));
112     return StatusWithSize::OutOfRange();
113   }
114 
115   // Check in erased state
116   for (unsigned i = 0; i < data.size(); i++) {
117     if (buffer_[address + i] != kErasedValue) {
118       PW_LOG_ERROR("Writing to previously written address: %x",
119                    unsigned(address));
120       return StatusWithSize::Unknown();
121     }
122   }
123 
124   // Check for any injected write errors
125   Status status = FlashError::Check(write_errors_, address, data.size());
126   std::memcpy(&buffer_[address], data.data(), data.size());
127   return StatusWithSize(status, data.size());
128 }
129 
FlashAddressToMcuAddress(Address address) const130 std::byte* FakeFlashMemory::FlashAddressToMcuAddress(Address address) const {
131   if (address > sector_count() * sector_size_bytes()) {
132     PW_LOG_ERROR(
133         "FlashAddressToMcuAddress beyond end of memory; address %x, max "
134         "address %x",
135         unsigned(address),
136         unsigned(sector_count() * sector_size_bytes()));
137     return nullptr;
138   }
139   return buffer_.data() + address;
140 }
141 
142 }  // namespace pw::kvs
143