SOME/IP to Classic Signal Mapping

/* Gateway BSW SWC: Adaptive → Classic signal bridge */

/* SOME/IP serialization rules (AUTOSAR AP SWS):
   - Integers: Big-endian unless configured otherwise
   - Structs: members packed in declaration order, no padding unless aligned
   - Strings: 4-byte length prefix + UTF-8 bytes */

typedef struct {
    uint32_t someip_header[2];   /* 8 bytes: MsgID, Length, RequestID, version */
    uint16_t audioVolume;         /* bytes 8-9: BE uint16 */
    uint8_t  volumeValid;         /* byte 10: validity flag */
    uint8_t  reserved;            /* byte 11: alignment */
} SomeIP_AudioEvent_t;

FUNC(void, GW_CODE) Gateway_SOMEIP_to_Classic_Runnable(void)
{
    SomeIP_AudioEvent_t event;

    /* 1. Read from IPC shared memory (Adaptive writes, Classic reads) */
    HwSemaphore_Acquire(HW_SEM_IPC_AUDIO);
    if (ipc_shared_mem.audio_event_new_flag) {
        memcpy(&event, &ipc_shared_mem.audio_event, sizeof(event));
        ipc_shared_mem.audio_event_new_flag = 0;
        HwSemaphore_Release(HW_SEM_IPC_AUDIO);

        /* 2. Deserialize: SOME/IP BE uint16 → Classic uint16 */
        uint16 volumeClassic = (uint16)(event.audioVolume); /* already BE on Cortex-R */

        /* 3. Write to Classic COM signal */
        if (event.volumeValid) {
            (void)Com_SendSignal(COM_SIG_AUDIO_VOLUME, &volumeClassic);
        } else {
            (void)Com_InvalidateSignal(COM_SIG_AUDIO_VOLUME);
        }
    } else {
        HwSemaphore_Release(HW_SEM_IPC_AUDIO);
    }
}

/* SOME/IP event arrives at 20ms; Classic COM Tx fires at 10ms */
/* Gateway uses last-is-best: same value retransmitted every 10ms */
/* until next SOME/IP event updates it */

static uint16 lastAudioVolume = 0;
static boolean volumeValid = FALSE;

/* Called from 20ms SOME/IP event handler */
void Gateway_UpdateAudioVolume(uint16 newVolume, boolean valid)
{
    /* Spinlock protects against 10ms COM task reading simultaneously */
    GetSpinlock(SPINLOCK_GW_AUDIO);
    lastAudioVolume = newVolume;
    volumeValid = valid;
    ReleaseSpinlock(SPINLOCK_GW_AUDIO);
}

/* Called from 10ms COM task (BSW SWC runnable) */
FUNC(void, GW_CODE) Gateway_AudioVolume_Runnable(void)
{
    uint16 volume;
    boolean valid;
    GetSpinlock(SPINLOCK_GW_AUDIO);
    volume = lastAudioVolume;
    valid  = volumeValid;
    ReleaseSpinlock(SPINLOCK_GW_AUDIO);

    if (valid) {
        (void)Com_SendSignal(COM_SIG_AUDIO_VOLUME, &volume);
    } else {
        (void)Com_InvalidateSignal(COM_SIG_AUDIO_VOLUME);
    }
}