TEE_Result TA_CreateEntryPoint()

in TAs/optee_ta/fTPM/fTPM.c [112:193]
47 lines of code
7 McCabe index (conditional complexity)

TEE_Result TA_CreateEntryPoint(void)
{
    #define STARTUP_SIZE 0x0C

    uint8_t startupClear[STARTUP_SIZE] = { 0x80, 0x01, 0x00, 0x00, 0x00, 0x0c,
                                           0x00, 0x00, 0x01, 0x44, 0x00, 0x00 };
    uint8_t startupState[STARTUP_SIZE] = { 0x80, 0x01, 0x00, 0x00, 0x00, 0x0c,
                                           0x00, 0x00, 0x01, 0x44, 0x00, 0x01 };
    uint32_t respLen;
    uint8_t *respBuf;

    // If we've been here before, don't init again.
    if (fTPMInitialized) {
        // We may have had TA_DestroyEntryPoint called but we didn't 
        // actually get torn down. Re-NVEnable, just in case.
        if (_plat__NVEnable(NULL) == 0) {
            TEE_Panic(TEE_ERROR_BAD_STATE);
        }
        return TEE_SUCCESS;
    }

    // Initialize NV admin state
    _admin__NvInitState();

    // If we fail to open fTPM storage we cannot continue.
    if (_plat__NVEnable(NULL) == 0) {
        TEE_Panic(TEE_ERROR_BAD_STATE);
    }

    // This only occurs when there is no previous NV state, i.e., on first
    // boot, after recovering from data loss, we reset the platform, etc.
    if (_plat__NvNeedsManufacture()) {
        DMSG("TPM_Manufacture\n");
        TPM_Manufacture(1);
    }

    // "Power-On" the platform
    _plat__Signal_PowerOn();

    // Internal init for reference implementation
    _TPM_Init();

    // Startup with state
    if (g_chipFlags.fields.TpmStatePresent) {

        // Re-use request buffer for response (ignored)
        respBuf = startupState;
        respLen = STARTUP_SIZE;

        ExecuteCommand(STARTUP_SIZE, startupState, &respLen, &respBuf);
        if (fTPMResponseCode(respLen, respBuf) == TPM_RC_SUCCESS) {
            goto Exit;
        }

#ifdef fTPMDebug
        DMSG("Fall through to startup clear\n");
#endif

        //DMSG("Start self test");
        //CryptSelfTest(1);

        goto Clear;
    }

Clear:
    // Re-use request buffer for response (ignored)
    respBuf = startupClear;
    respLen = STARTUP_SIZE;

    // Fall back to a Startup Clear
    ExecuteCommand(STARTUP_SIZE, startupClear, &respLen, &respBuf);

Exit:
    // Init is complete, indicate so in fTPM admin state.
    g_chipFlags.fields.TpmStatePresent = 1;
    _admin__SaveChipFlags();

    // Initialization complete
    fTPMInitialized = true;

    return TEE_SUCCESS;
}