File syn_fwimage.h¶

File List > src > syntropic > system > syn_fwimage.h
#ifndef SYN_FWIMAGE_H
#define SYN_FWIMAGE_H

#include "../common/syn_defs.h"
#include "../util/syn_crc.h"

#include <stdbool.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

/* ── Magic number ───────────────────────────────────────────────────────── */

#define SYN_FW_MAGIC 0x53594E46u /* "SYNF" in little-endian */

/* ── Image state ────────────────────────────────────────────────────────── */

typedef enum {
    SYN_FW_STATE_EMPTY = 0xFF,     
    SYN_FW_STATE_WRITING = 0x01,   
    SYN_FW_STATE_NEW = 0x02,       
    SYN_FW_STATE_TESTING = 0x03,   
    SYN_FW_STATE_CONFIRMED = 0x04, 
    SYN_FW_STATE_INVALID = 0x00,   
} SYN_FwState;

/* ── Image header ───────────────────────────────────────────────────────── */

typedef struct {
    uint32_t magic;        
    uint32_t version_code; 
    uint32_t image_size;   
    uint32_t image_crc;    
    uint8_t state;         
    uint8_t reserved[3];   
#if defined(SYN_FW_USE_HMAC) && SYN_FW_USE_HMAC
    uint8_t image_hmac[32]; 
#endif
    uint32_t header_crc; 
} SYN_FwImageHeader;

/* ── Validation ─────────────────────────────────────────────────────────── */

static inline bool syn_fwimage_header_valid(const SYN_FwImageHeader *hdr)
{
    if (hdr->magic != SYN_FW_MAGIC)
        return false;

    /* CRC-32 over all fields before header_crc, including padding and HMAC (if present).
     * offsetof correctly accounts for struct layout and padding. */
    uint32_t crc = syn_crc32(hdr, offsetof(SYN_FwImageHeader, header_crc));
    return (crc == hdr->header_crc);
}

static inline void syn_fwimage_seal_header(SYN_FwImageHeader *hdr)
{
    hdr->header_crc = syn_crc32(hdr, offsetof(SYN_FwImageHeader, header_crc));
}

static inline bool syn_fwimage_is_bootable(const SYN_FwImageHeader *hdr)
{
    if (!syn_fwimage_header_valid(hdr))
        return false;
    return (hdr->state == SYN_FW_STATE_NEW || hdr->state == SYN_FW_STATE_TESTING ||
            hdr->state == SYN_FW_STATE_CONFIRMED);
}

#ifdef __cplusplus
}
#endif

#endif /* SYN_FWIMAGE_H */