kopia lustrzana https://github.com/espressif/esp-idf
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doc | ||
include | ||
private_include | ||
test | ||
test_wl_host | ||
.gitignore | ||
Partition.cpp | ||
README.rst | ||
SPI_Flash.cpp | ||
WL_Flash.cpp | ||
component.mk | ||
crc32.cpp | ||
crc32.h | ||
wear_levelling.cpp |
README.rst
Wear Levelling APIs =================== Overview -------- Most of the flash devices and specially SPI flash devices that are used in ESP32 have sector based organization and have limited amount of erase/modification cycles per memory sector. To avoid situation when one sector reach the limit of erases when other sectors was used not often, we have made a component that avoid this situation. The wear levelling component share the amount of erases between all sectors in the memory without user interaction. The wear_levelling component contains APIs related to reading, writing, erasing, memory mapping data in the external SPI flash through the partition component. It also has higher-level APIs which work with FAT filesystem defined in the :doc:`FAT filesystem </api-reference/storage/fatfs>`. The wear levelling component does not cache data in RAM. Write and erase functions modify flash directly, and flash contents is consistent when the function returns. Wear Levelling access APIs -------------------------- This is the set of APIs for working with data in flash: - ``wl_mount`` mount wear levelling module for defined partition - ``wl_unmount`` used to unmount levelling module - ``wl_erase_range`` used to erase range of addresses in flash - ``wl_write`` used to write data to the partition - ``wl_read`` used to read data from the partition - ``wl_size`` return size of avalible memory in bytes - ``wl_sector_size`` returns size of one sector Generally, try to avoid using the raw wear levelling functions in favor of filesystem-specific functions. Memory Size ----------- The memory size calculated in the wear Levelling module based on parameters of partition. The module use few sectors of flash for internal data.