prf::config::PicoLittleFsConfigBackend class final
#include <config/pico_littlefs_backend.hpp>

PicoSDK flash backend that stores config section files in LittleFS.

It provides power-loss-tolerant persistence, wear leveling, and atomic rename while keeping ConfigStore independent from hardware details. Partition is always placed at the end of on-chip flash and its size is controlled by CONFIG_LFS_PARTITION_SIZE_BYTES at build time.

Base classes

class IConfigBackend: Abstract storage backend used by ConfigStore.

Public types

struct FilesystemUsage
struct Options: Backend setup options.

Constructors, destructors, conversion operators

PicoLittleFsConfigBackend(): Constructs backend with default options.
PicoLittleFsConfigBackend(const Options& options) explicit: Constructs backend with explicit flash-layout options.
~PicoLittleFsConfigBackend() override: Unmounts filesystem when mounted.

Public functions

auto filesystem_usage(FilesystemUsage* out_usage) -> bool: Returns current LittleFS usage counters for configured partition.
auto last_error_op() const -> const char*: Returns short identifier of operation that produced last error.
auto last_flash_error() const -> int: Returns last flash_safe_execute return code observed by callbacks.
auto last_lfs_error() const -> int: Returns last LittleFS error code observed by backend operations.
auto last_mount_recovery_action() const -> const char*: Returns last mount-recovery action selected by backend policy.
auto partition_size_bytes() const -> uint32_t: Returns configured flash partition size in bytes.
auto read_file(std::string_view relative_path, std::vector<uint8_t>* out_bytes) -> ConfigReadStatus override: Reads one section payload file from LittleFS.
auto remove_file(std::string_view relative_path) -> bool override: Removes one section payload file.
auto storage_offset_bytes() const -> uint32_t: Returns configured flash partition offset from start of XIP flash.
auto valid() const -> bool: Returns true when flash layout was validated and backend can mount.
auto write_file_atomic(std::string_view relative_path, const std::vector<uint8_t>& bytes) -> bool override: Writes one section payload file with temp-file + rename semantics.

Function documentation

const char* prf::config::PicoLittleFsConfigBackend::last_mount_recovery_action() const

Returns last mount-recovery action selected by backend policy.

The value is reset to none after a later fully successful mount path.