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esphome/esphome/components/esp8266/preferences.cpp
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9.5 KiB
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#ifdef USE_ESP8266
#include <c_types.h>
extern "C" {
#include "spi_flash.h"
}
#include "esphome/core/defines.h"
#include "esphome/core/helpers.h"
#include "esphome/core/log.h"
#include "esphome/core/preferences.h"
#include "preferences.h"
#include <cstring>
namespace esphome::esp8266 {
static const char *const TAG = "esp8266.preferences";
static uint32_t *s_flash_storage = nullptr; // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
static bool s_prevent_write = false; // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
static bool s_flash_dirty = false; // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
static constexpr uint32_t ESP_RTC_USER_MEM_START = 0x60001200;
static constexpr uint32_t ESP_RTC_USER_MEM_SIZE_WORDS = 128;
static constexpr uint32_t ESP_RTC_USER_MEM_SIZE_BYTES = ESP_RTC_USER_MEM_SIZE_WORDS * 4;
// RTC memory layout for preferences:
// - Eboot region: RTC words 0-31 (reserved, mapped from preference offset 96-127)
// - Normal region: RTC words 32-127 (mapped from preference offset 0-95)
static constexpr uint32_t RTC_EBOOT_REGION_WORDS = 32; // Words 0-31 reserved for eboot
static constexpr uint32_t RTC_NORMAL_REGION_WORDS = 96; // Words 32-127 for normal prefs
static constexpr uint32_t PREF_TOTAL_WORDS = RTC_EBOOT_REGION_WORDS + RTC_NORMAL_REGION_WORDS; // 128
// Maximum preference size in words (limited by uint8_t length_words field)
static constexpr uint32_t MAX_PREFERENCE_WORDS = 255;
#define ESP_RTC_USER_MEM ((uint32_t *) ESP_RTC_USER_MEM_START)
#ifdef USE_ESP8266_PREFERENCES_FLASH
static constexpr uint32_t ESP8266_FLASH_STORAGE_SIZE = 128;
#else
static constexpr uint32_t ESP8266_FLASH_STORAGE_SIZE = 64;
#endif
static inline bool esp_rtc_user_mem_read(uint32_t index, uint32_t *dest) {
if (index >= ESP_RTC_USER_MEM_SIZE_WORDS) {
return false;
}
*dest = ESP_RTC_USER_MEM[index]; // NOLINT(performance-no-int-to-ptr)
return true;
}
static inline bool esp_rtc_user_mem_write(uint32_t index, uint32_t value) {
if (index >= ESP_RTC_USER_MEM_SIZE_WORDS) {
return false;
}
if (index < 32 && s_prevent_write) {
return false;
}
auto *ptr = &ESP_RTC_USER_MEM[index]; // NOLINT(performance-no-int-to-ptr)
*ptr = value;
return true;
}
extern "C" uint32_t _SPIFFS_end; // NOLINT
static uint32_t get_esp8266_flash_sector() {
union {
uint32_t *ptr;
uint32_t uint;
} data{};
data.ptr = &_SPIFFS_end;
return (data.uint - 0x40200000) / SPI_FLASH_SEC_SIZE;
}
static uint32_t get_esp8266_flash_address() { return get_esp8266_flash_sector() * SPI_FLASH_SEC_SIZE; }
static inline size_t bytes_to_words(size_t bytes) { return (bytes + 3) / 4; }
template<class It> uint32_t calculate_crc(It first, It last, uint32_t type) {
uint32_t crc = type;
while (first != last) {
crc ^= (*first++ * 2654435769UL) >> 1;
}
return crc;
}
static bool save_to_flash(size_t offset, const uint32_t *data, size_t len) {
for (uint32_t i = 0; i < len; i++) {
uint32_t j = offset + i;
if (j >= ESP8266_FLASH_STORAGE_SIZE)
return false;
uint32_t v = data[i];
uint32_t *ptr = &s_flash_storage[j];
if (*ptr != v)
s_flash_dirty = true;
*ptr = v;
}
return true;
}
static bool load_from_flash(size_t offset, uint32_t *data, size_t len) {
for (size_t i = 0; i < len; i++) {
uint32_t j = offset + i;
if (j >= ESP8266_FLASH_STORAGE_SIZE)
return false;
data[i] = s_flash_storage[j];
}
return true;
}
static bool save_to_rtc(size_t offset, const uint32_t *data, size_t len) {
for (uint32_t i = 0; i < len; i++) {
if (!esp_rtc_user_mem_write(offset + i, data[i]))
return false;
}
return true;
}
static bool load_from_rtc(size_t offset, uint32_t *data, size_t len) {
for (uint32_t i = 0; i < len; i++) {
if (!esp_rtc_user_mem_read(offset + i, &data[i]))
return false;
}
return true;
}
// Stack buffer size - 16 words total: up to 15 words of preference data + 1 word CRC (60 bytes of preference data)
// This handles virtually all real-world preferences without heap allocation
static constexpr size_t PREF_BUFFER_WORDS = 16;
class ESP8266PreferenceBackend : public ESPPreferenceBackend {
public:
uint32_t type = 0;
uint16_t offset = 0;
uint8_t length_words = 0; // Max 255 words (1020 bytes of data)
bool in_flash = false;
bool save(const uint8_t *data, size_t len) override {
if (bytes_to_words(len) != this->length_words)
return false;
const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
uint32_t *buffer = buffer_alloc.get();
memset(buffer, 0, buffer_size * sizeof(uint32_t));
memcpy(buffer, data, len);
buffer[this->length_words] = calculate_crc(buffer, buffer + this->length_words, this->type);
return this->in_flash ? save_to_flash(this->offset, buffer, buffer_size)
: save_to_rtc(this->offset, buffer, buffer_size);
}
bool load(uint8_t *data, size_t len) override {
if (bytes_to_words(len) != this->length_words)
return false;
const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
uint32_t *buffer = buffer_alloc.get();
bool ret = this->in_flash ? load_from_flash(this->offset, buffer, buffer_size)
: load_from_rtc(this->offset, buffer, buffer_size);
if (!ret)
return false;
if (buffer[this->length_words] != calculate_crc(buffer, buffer + this->length_words, this->type))
return false;
memcpy(data, buffer, len);
return true;
}
};
class ESP8266Preferences : public ESPPreferences {
public:
uint32_t current_offset = 0;
uint32_t current_flash_offset = 0; // in words
void setup() {
s_flash_storage = new uint32_t[ESP8266_FLASH_STORAGE_SIZE]; // NOLINT
ESP_LOGVV(TAG, "Loading preferences from flash");
{
InterruptLock lock;
spi_flash_read(get_esp8266_flash_address(), s_flash_storage, ESP8266_FLASH_STORAGE_SIZE * 4);
}
}
ESPPreferenceObject make_preference(size_t length, uint32_t type, bool in_flash) override {
const uint32_t length_words = bytes_to_words(length);
if (length_words > MAX_PREFERENCE_WORDS) {
ESP_LOGE(TAG, "Preference too large: %u words", static_cast<unsigned int>(length_words));
return {};
}
const uint32_t total_words = length_words + 1; // +1 for CRC
uint16_t offset;
if (in_flash) {
if (this->current_flash_offset + total_words > ESP8266_FLASH_STORAGE_SIZE)
return {};
offset = static_cast<uint16_t>(this->current_flash_offset);
this->current_flash_offset += total_words;
} else {
uint32_t start = this->current_offset;
bool in_normal = start < RTC_NORMAL_REGION_WORDS;
// Normal: offset 0-95 maps to RTC offset 32-127
// Eboot: offset 96-127 maps to RTC offset 0-31
if (in_normal && start + total_words > RTC_NORMAL_REGION_WORDS) {
// start is in normal but end is not -> switch to Eboot
this->current_offset = start = RTC_NORMAL_REGION_WORDS;
in_normal = false;
}
if (start + total_words > PREF_TOTAL_WORDS)
return {}; // Doesn't fit in RTC memory
// Convert preference offset to RTC memory offset
offset = static_cast<uint16_t>(in_normal ? start + RTC_EBOOT_REGION_WORDS : start - RTC_NORMAL_REGION_WORDS);
this->current_offset = start + total_words;
}
auto *pref = new ESP8266PreferenceBackend(); // NOLINT(cppcoreguidelines-owning-memory)
pref->offset = offset;
pref->type = type;
pref->length_words = static_cast<uint8_t>(length_words);
pref->in_flash = in_flash;
return pref;
}
ESPPreferenceObject make_preference(size_t length, uint32_t type) override {
#ifdef USE_ESP8266_PREFERENCES_FLASH
return make_preference(length, type, true);
#else
return make_preference(length, type, false);
#endif
}
bool sync() override {
if (!s_flash_dirty)
return true;
if (s_prevent_write)
return false;
ESP_LOGD(TAG, "Saving");
SpiFlashOpResult erase_res, write_res = SPI_FLASH_RESULT_OK;
{
InterruptLock lock;
erase_res = spi_flash_erase_sector(get_esp8266_flash_sector());
if (erase_res == SPI_FLASH_RESULT_OK) {
write_res = spi_flash_write(get_esp8266_flash_address(), s_flash_storage, ESP8266_FLASH_STORAGE_SIZE * 4);
}
}
if (erase_res != SPI_FLASH_RESULT_OK) {
ESP_LOGE(TAG, "Erasing failed");
return false;
}
if (write_res != SPI_FLASH_RESULT_OK) {
ESP_LOGE(TAG, "Writing failed");
return false;
}
s_flash_dirty = false;
return true;
}
bool reset() override {
ESP_LOGD(TAG, "Erasing storage");
SpiFlashOpResult erase_res;
{
InterruptLock lock;
erase_res = spi_flash_erase_sector(get_esp8266_flash_sector());
}
if (erase_res != SPI_FLASH_RESULT_OK) {
ESP_LOGE(TAG, "Erasing failed");
return false;
}
// Protect flash from writing till restart
s_prevent_write = true;
return true;
}
};
void setup_preferences() {
auto *pref = new ESP8266Preferences(); // NOLINT(cppcoreguidelines-owning-memory)
pref->setup();
global_preferences = pref;
}
void preferences_prevent_write(bool prevent) { s_prevent_write = prevent; }
} // namespace esphome::esp8266
namespace esphome {
ESPPreferences *global_preferences; // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
} // namespace esphome
#endif // USE_ESP8266