File syn_param.h¶

FileList > src > syntropic > storage > syn_param.h

Persistent parameter store with wear leveling. More...

#include "../common/syn_defs.h"
#include "../port/syn_port_flash.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_ParamSlotHeader Slot header — stored at the beginning of each parameter slot.
struct	SYN_ParamStore Wear-leveled flash parameter store instance.

Public Functions¶

Type	Name
SYN_Status	syn_param_erase_all (SYN_ParamStore * store) Erase all parameter data (factory reset).
SYN_Status	syn_param_init (SYN_ParamStore * store, uint32_t flash_base, uint8_t sector_count, uint16_t data_size) Initialize the parameter store.
SYN_Status	syn_param_load (const SYN_ParamStore * store, void * data) Load parameters from the latest valid slot.
SYN_Status	syn_param_save (SYN_ParamStore * store, const void * data) Save parameters to the next slot (wear-leveled).

Public Static Functions¶

Type	Name
uint16_t	syn_param_write_count (const SYN_ParamStore * store) Get the current write count (approximate wear indicator).

Macros¶

Type	Name
define	SYN_PARAM_MAGIC `0xC0DEu` Magic number for parameter slot headers.

Detailed Description¶

Stores key-value parameters in flash with: * Wear leveling: Slot rotation across flash sectors * Integrity: CRC-16 on each slot * Atomic writes: Sequence numbers to identify the latest valid slot * No dynamic allocation: Fixed-size parameter block, caller-owned RAM

** **

The flash region is divided into sectors. Each sector contains N slots. Each slot stores the full parameter block + header (sequence, CRC). Writes go to the next free slot. When a sector is full, the next sector is erased and writing continues there.

Sector 0:  [slot0][slot1][slot2]...[slotN]
Sector 1:  [slot0][slot1]...
Sector 2:  ...

The highest sequence number with a valid CRC is the active slot.

** **

// Define your parameters as a struct
typedef struct {
    uint16_t brightness;
    int16_t  offset;
    uint8_t  mode;
} MyParams;

static SYN_ParamStore store;
static MyParams params;

syn_param_init(&store, FLASH_PARAM_START, 2, sizeof(MyParams));
syn_param_load(&store, &params);   // loads latest valid or defaults

params.brightness = 80;
syn_param_save(&store, &params);   // writes to next slot

Public Functions Documentation¶

function syn_param_erase_all¶

Erase all parameter data (factory reset).

SYN_Status syn_param_erase_all (
    SYN_ParamStore * store
)

Parameters:

store Store instance.

Returns:

SYN_OK on success.

function syn_param_init¶

Initialize the parameter store.

SYN_Status syn_param_init (
    SYN_ParamStore * store,
    uint32_t flash_base,
    uint8_t sector_count,
    uint16_t data_size
)

Scans flash to find the latest valid slot. Must be called before load or save.

Parameters:

store Store instance.
flash_base Start address of the flash region for params.
sector_count Number of flash sectors to use for wear leveling.
data_size Size of the parameter struct in bytes.

Returns:

SYN_OK if at least one valid slot was found, SYN_ERROR if flash is blank (use defaults).

function syn_param_load¶

Load parameters from the latest valid slot.

SYN_Status syn_param_load (
    const SYN_ParamStore * store,
    void * data
)

Parameters:

store Initialized store.
data Buffer to receive the parameter data (must be data_size bytes).

Returns:

SYN_OK on success, SYN_ERROR if no valid data found.

function syn_param_save¶

Save parameters to the next slot (wear-leveled).

SYN_Status syn_param_save (
    SYN_ParamStore * store,
    const void * data
)

Writes to the next free slot, rotating across sectors. When a sector fills up, the next sector is erased and writing continues there.

Parameters:

store Initialized store.
data Parameter data to save (must be data_size bytes).

Returns:

SYN_OK on success, SYN_ERROR on flash write failure.

Public Static Functions Documentation¶

function syn_param_write_count¶

Get the current write count (approximate wear indicator).

static inline uint16_t syn_param_write_count (
    const SYN_ParamStore * store
)

Parameters:

store Store instance.

Returns:

The sequence number, which increments with each save.

Macro Definition Documentation¶

define SYN_PARAM_MAGIC¶

Magic number for parameter slot headers.

#define SYN_PARAM_MAGIC `0xC0DEu`

The documentation for this class was generated from the following file src/syntropic/storage/syn_param.h