#include <string.h>
#include <zephyr/kernel.h>
#include <zephyr/init.h>
#include <zephyr/sys/crc.h>
#include <zephyr/logging/log.h>
#include <safe_data/safe_data.h>

Macros
#define	SAFE_TAG_SEED 0x0u
#define	SAFE_DATA_KIND_COUNT (SAFE_DATA_FAULT_KIND_MUTATOR_CLAMPED + 1)
#define	SAFE_DATA_KAT_EXPECTED 0xCBF43926u

Functions
	LOG_MODULE_REGISTER (safe_data, CONFIG_SAFE_DATA_LOG_LEVEL)
static uint32_t	safe_tag_update (uint32_t c, const uint8_t *p, size_t len)
static uint32_t	safe_tag (const void *p, size_t len)
static uint32_t	safe_tag_inverted (const void *shadow, size_t len)
static bool	payload_matches_shadow (const void payload, const void shadow, size_t len)
void	safe_data_fault_handler (const void *payload, size_t len)
	Legacy user-overridable (weak) fault handler.
int	safe_data_fault_handler_register (safe_data_fault_cb_t cb)
	Register the fault handler callback.
int	safe_data_stats_get (struct safe_data_stats *out)
	Snapshot the global statistics.
void	safe_data_stats_reset (void)
	Reset all statistics counters to zero.
static void	safe_event (enum safe_data_fault_kind kind, const void *payload, size_t len)
int	safe_data_init (struct k_mutex lock, void payload, size_t len, uint32_t crc, void shadow)
	Initialise the lock and seal the current payload contents.
static int	verify_quiet (const void payload, size_t len, uint32_t crc, const void shadow)
int	safe_data_verify (const void payload, size_t len, uint32_t crc, const void shadow)
	Verify payload integrity. Pure: read-only and lock-free; it NEVER modifies the payload, so it is safe to call concurrently with writers (a transient mismatch may then be reported - callers needing atomicity should use the higher-level helpers).
int	safe_data_verify_repair (void payload, size_t len, uint32_t crc, void shadow)
	Verify payload integrity and repair a recoverable fault in place.
int	safe_data_read (struct k_mutex lock, void payload, size_t len, uint32_t crc, void shadow, void *out)
	Verify under lock and copy the payload out to `out`.
int	safe_data_write (struct k_mutex lock, void payload, size_t len, uint32_t crc, void shadow, const void *in)
	Copy `in` into the payload under lock and reseal the integrity tag.
int	safe_data_update (struct k_mutex lock, void payload, size_t len, uint32_t crc, void shadow, safe_data_mutator_t fn, void *user)
	Atomic read-modify-write: lock, verify, run `fn`, reseal on success.
int	safe_data_commit (struct k_mutex lock, void payload, size_t len, uint32_t crc, void shadow)
	Reseal after an explicit external modification (advanced use). Lock, recompute the integrity tag, unlock.
int	safe_data_selftest (void)
	Self-test of the integrity mechanism itself.
int	safe_data_selftest_result (void)
	Result of the boot-time self-test (CONFIG_SAFE_DATA_SELFTEST_BOOT).
static int	safe_data_boot_selftest (void)
	SYS_INIT (safe_data_boot_selftest, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT)

Variables
static safe_data_fault_cb_t	fault_cb
static atomic_t	stat_counters [(SAFE_DATA_FAULT_KIND_MUTATOR_CLAMPED+1)]
static volatile bool	event_mute
static int	boot_selftest_result = -EAGAIN